[cm ]
Based on the knowledge of the structure of hemp fiber, its chemical and physical structure and properties, its possible application in various technical solutions is known. However, some applications require changing these properties. In order to modify them, in basic technological operations, these are mechanical modifications such as cutting or grinding. More advanced techniques that significantly change the properties, however, are based on chemical modifications such as alkalization, acetylation, esterification, silanization, acrylation, or through the use of carboxylic acids, anhydrides or solvent replacement. Each of the mentioned physical and chemical modifications causes a specific change in the properties of the hemp fiber and adjusts it to the most interactive use. This topic is explored more in-depth in the extensive work of Tanasa et al. [ 28 ].
Plants are the main source of natural extracts. Their matrix is used to extract all the natural compounds needed by humans, such as oils, essential oils, compounds with healing properties and others. Hemp, in this case, is also a rich source of these substances. In order to obtain them and collect the appropriate fraction, an appropriate extraction method should be selected. The literature indicates two main ones: the method with the use of organic solvents and the method with the use of supercritical gases. In the case of the first of them, one of the first steps is the comminution of the plant material and then treatment with a suitably selected organic solvent or their mixture at a predetermined temperature. The solvent flushes out specific compounds from the plant matrix as a result of its diffusion through its tissue. Unfortunately, this method suffers from a number of disadvantages, such as low selectivity, contamination of the extract obtained with residues of often toxic solvents, and the effect of high temperature as a factor causing the degradation of unstable natural compounds. The second method, i.e., the use of supercritical gases (most often carbon dioxide), is more innovative and allows avoiding the use of both elevated temperatures and organic solvents that are unfriendly to the natural environment. In this case, the solubility of active natural compounds that depend on such physicochemical factors as gas pressure, the temperature of the extraction process-by controlling these parameters, the gas diffusivity and polarity are controlled, which affects the solubility of the extracted substances. An additional advantage is that this process is carried out under inert gas conditions, which significantly reduces the oxidation of unstable compounds in the air atmosphere. Unfortunately, a small range of substances dissolves very well in supercritical carbon dioxide, which is why small amounts of other solvents are often used as cosolvents to help flush out the expected natural compounds from the matrix [ 63 ].
As the research conducted so far shows, over 500 active substances have been discovered in Cannabis Sativa , which can be classified into 18 main groups of chemical substances. Among other things, they are rich in 12 fatty acids, about 200 terpenes and 20 heterocyclic compounds containing nitrogen atoms in their ring structure, over 50 hydrocarbons and as many as 100 cannabinoids, of which hemp is the most famous. The main cannabidiols found in this plant include delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN). The structures of the listed compounds have been collected and presented in Figure 2 . These salivae also contain various polyphenols with antioxidant properties, coloring compounds and polysaccharides [ 64 ].
Structural formulas of cannabinoids occurring in hemp (CBD—cannabidiol; CBN—cannabinol; CBG—cannabigerol; CBC—cannabichromene; THC—tetrahydrocannabinol; THCV—tetrahydrocannabivarin).
Previous research in cannabis has discovered CBD was shown to have very strong antioxidant, anti-inflammatory and bactericidal properties and is used in anxiolytic, anticonvulsant and neurological therapies, while CBG also has analgesic properties. All of the mentioned compounds belong to the group of phytocannabinoids occurring depending on the variety and the way of cultivation in various quantities in cannabis. Cannabigerol is a precursor to the formation of compounds such as THC, CBD and cannabichromene (CBC). Unfortunately, THC, due to its psychoactive effects, has made cannabis infamous, as it contains a wide range of active, health-promoting natural compounds. CBD, CBC, and CBG are indicated as one of the main potential medicinal substances that can help people with diseases such as cancer, neurological diseases, bacterial infections and severe inflammation in the body. Strong healing properties are indicated even among drug-resistant bacteria, such as the Staphylococcus aureus strain. Hemp also contains various polyphenols with antioxidant properties, coloring compounds and polysaccharides [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 ].
Waxes are still a little-known and studied part of the hemp plants. Its source may be hemp dust and waste generated during the processing of entire plants, fibers, seeds and leaves in various technological processes. This dust and waste is usually a waste product, but in the future, it may become a potential source of hemp waxes for use as an ingredient in cosmetics or as a natural polymer plasticizer [ 69 ]. They are part of the oil fraction which, according to the data contained in Table 2 given by L. Apostol in his article, has the following composition [ 78 ]:
Composition of the oily fraction derived from hemp seeds.
Component | Value [%] |
---|---|
The content of the oily fraction in the entire mass of the hemp seed | 28.7 |
Palmitic acid | 6.96 |
Stearic acid | 2.74 |
Arachidic acid | 0.77 |
10.47 | |
Oleic acid | 13.64 |
Linoleic acid | 56.35 |
Gamma-linoleic acid | 1.35 |
Alpha-linoleic acid | 17.30 |
Stearidonic acid | 0.50 |
Eicosenoic acid | 0.39 |
89.53 |
Attard et al., as a result of their research, performed an extraction using the supercritical carbon dioxide method and the Soxhlet extraction using heptane. In all the samples tested, they detected the presence of hydrocarbons, fatty acids, alcohols, fatty aldehydes, sterols, cannabinols and wax esters. The last of the mentioned groups of compounds were characterized by chain length from C 38 to C 58 . The most common wax ester in the samples was C 46 , and then C 44 . Interestingly, almost all wax esters were lost from hemp waste processed during paper production. The largest amounts of waxes were obtained as a result of supercritical extraction carried out at a temperature of about 50 °C and high pressure of 350 bar [ 69 ].
Other studies on cannabis samples by Francisco et al. showed the following chemical composition of the waxes obtained from the ethanol suspension [ 79 ]. These data are presented in Table 3 below.
The content of the fraction in the entire mass of the hemp waxes.
Component | Value [%] |
---|---|
pentacosane | 1.92–2.17 |
heptacosane | 6.96–7.55 |
octacosane | 0.75–5.56 |
nonacosane | 9.92–10.51 |
triacontane | 0.44–0.58 |
dotriacontane | 0.49 |
tritriacontane | 1.58–2.06 |
pentatriacontane | 1.13–1.24 |
heptatriacontane | 1.18–1.23 |
sabinene | 0.31–0.51 |
p-cymene | 3.32–5.15 |
β-cubebene | 0.31–0.40 |
(−)-trans-caryophyllene | 5.90–7.22 |
β-copaene | 0.32–0.40 |
α-humulene | 0.51–0.94 |
(E,E)-β-farnesene | 0.30–0.33 |
γ-gurjunene | 0.27 |
γ-curcumene | 0.59–0.70 |
valencene | 0.51–0.60 |
germacrene A | 0.39–0.44 |
α-7-epi-selinene | 0.42–0.54 |
α-cadinene | 0.20–0.33 |
α-bisabolene | 1.63–2.50 |
(E,E)-α-farnesene | 0.28 |
dehydro-1,8-cineole | 1.23–1.99 |
isoborneol | 0.38 |
fenchone | 0.26–0.44 |
cis-thujone | 0.27 |
endo-fenchol | 0.26–0.28 |
cis-nerolidol | 2.50–2.84 |
trans-nerolidol | 0.43 |
caryophyllene oxide | 0.49–0.89 |
humulene epoxide II | 0.31–0.37 |
10-epi-γ-eudesmol | 0.61–0.82 |
1,10-di-epi-cubenol | 0.29–0.36 |
γ-eudesmol | 0.29–0.47 |
α-muurolol | 0.25–0.35 |
β-eudesmol | 0.67–1.01 |
α-bisabolol | 0.18 |
(2Z,6Z)-farnesol | 0.49 |
CBD | 4.20–9.67 |
CBC | 0.11–0.18 |
Δ -THC | 0.12–0.13 |
Δ -THC | 0.22–0.37 |
CBG | 0.07–0.22 |
CBN | 1.20–2.40 |
CBDA | 22.91–34.56 |
THCA | 5.78–5.89 |
heptanal | 0.22–0.61 |
2,4-hexadienal | 0.11 |
nonanal | 0.37 |
vanillin | 0.27 |
tridecanoic acid | 0.21–0.31 |
ethyl tetradecanoate | 0.42 |
hexadecenoic acid | 0.25–0.27 |
ethyl hexadecanoate | 0.22–0.31 |
As the research of the above scientists show, hemp waxes are rich not only in alkanes but also in monoterpenes, sesquiterpenes, terpenoids, but also in cannabinoids. This suggests that apart from the plasticizing and lubricating properties, the cannabis wax esters have strong healing and antioxidant properties. These products play a multi-functional role in their applications. However, these substances still require in-depth study because of the limited knowledge about them.
The subject of the use of cannabis in science, industry or the arts has gained prominence in recent years. As can be seen from the Figure 3 below, the popularity of this keyword in the Scopus database has increased nearly 10-fold over the last 20 years. This indicates a remarkable interest, particularly since 2015, in this plant. The possibility of its use in a wide range of applications and the development of the pro-ecological trend in the world causes newer and more advanced research towards the description of properties and applications of hemp plants in everyday products.
Change in the number of occurrences of the keyword “hemp” in the Scopus database in 2000–2021.
Fiber hemp is a species of the annual hemp plant. These plants do not contain psychoactive substances; they are used in many industries, reaching a height of 1.5–3.5 m under favorable conditions. The main direction of the use of hemp in agriculture is the production of straw. As a result of processing the straw of mono-hemp fibrous hemp, we obtain 25–30% of the fiber and about 70% of the shives. Hemp is an interesting plant in terms of ecology and economy. Their cultivation does not require the use of plant protection products or pesticides, and hemp itself inhibits the development of weeds, repels pests, is resistant to diseases and requires only minerals contained in the soil. This has a positive effect on the environment as it contributes to the improvement of soil systems [ 80 ]. A suitable example is that these plants have a pile system root, which loosens and ventilates the soil and improves its water conditions, making it more beneficial for all plants that coexist with cannabis. This brings about positive effects, positively influencing the development of the economy, especially everything in agricultural countries. A favorable pro-ecological effect on the environment may, to some extent, reduce the need to increase expenditure on environmental protection and climate change. As indicated in the work of Żuk-Gołaszewska et al., one hectare of hemp plants is capable of absorbing about 2.5 tons of carbon dioxide [ 80 ]. Agriculture is the main and basic source of food, but despite this, it is not an economically competitive sector of the economy compared to other industries. Hemp straw in agriculture is used as a source of fodder with very good nutritional parameters for farm animals, mainly cattle. However, apart from that, it is also used as highly efficient biomass in the processes of generating both thermal and electric energy, which was presented in Figure 4 below [ 81 ].
Processing cannabis for energy purposes.
One of the industries that use hemp is the food industry. Hemp food has been known for thousands of years and, at the same time, is a modern, fashionable and healthy food supplement containing valuable ingredients. The hemp seed based on which most hemp foods are prepared contains all of the amino acids and Omega 3, 6 and 9 fatty acids needed for the proper functioning of the human body, especially the brain, in appropriate proportions. About 35% of the seed content is easily digestible high-quality protein, but also contains dietary fiber to support the digestive system and proper digestion, as well as vitamins B and E. On the other hand, about 30% of the seed content is carbohydrates, providing energy for the body. Hemp seeds can be eaten raw, sprouted or powdered as flour. They are used for baking, as well as hemp milk made from them, similar to soy. About 27–38% of the seed weight can be extracted into hemp oil rich in unsaturated fatty acids, as Fike pointed out in his article [ 9 ]. The competition for hemp-based food products is the entire food market, especially organic food. Food products made on the basis of hemp have a positive health-promoting effect on our body. They affect cell regeneration, slow down the aging processes, inhibit the development of cancer cells and have a significant effect on immunity [ 9 ].
As Kaniewski pointed out in his work, hemp seeds are a rich source of edestin, phytic acid, choline, trigonelline, lecithin, chlorophyll, vitamin K and tocopherols, as well as many micro and macro elements such as iron, calcium, zinc, phosphorus, magnesium and vitamin E, which strong antioxidant properties. It protects unsaturated fatty acids against oxidation reactions, thanks to which they retain their properties. In addition, it has a positive effect on the circulatory system, making blood vessels more flexible, improving blood flow and reducing the possibility of ischemic heart disease or atherosclerosis [ 82 ]. Vitamin E is otherwise known as alpha-tocopherol (5.66% of all tocopherols). Cannabis also contains gamma-tocopherol (89.11%), beta-tocopherol (0.33%) and delta-tocopherol (4.90%). These are antioxidant compounds that are involved through the interaction and active quenching of DPPH and ABTS + cationic radicals. They form metal transfer chelates with them. They also absorb oxygen radicals generated by AAPPH (ORAC) and prevent lipid peroxidation in human LDL. Thanks to such good antioxidant properties, these compounds protect proteins, lipid membranes and DNA against the harmful effects of radicals that cause oxidative damage, as mentioned in the article by Żuk-Gołaszewska et al. [ 80 ]. Hemp food improves digestion and is beneficial for the healthy digestive system, and also lowers cholesterol, reducing the risk of heart attacks, one of the main civilization diseases of the 21st century in highly developed countries [ 78 ].
The fibers obtained from Cannabis Sativa can be used to produce high-quality fabrics that are used in the clothing industry around the world. It is worth emphasizing that the production of hemp fibers is more ecological and less water-absorbing than the widely produced and used cotton. According to Columbia History of the World, hemp fabrics have been known to man since the eighth millennium BC. From the 5th century BC up to the stage of the industrial revolution, hemp fabrics were used in the production of about 90% of sails. Until the United States of America introduced the so-called Marihuana Tax Act (1937), which also included industrial hemp, about 80% of all fabrics intended for clothes and other everyday textile products were made of hemp fabrics. According to specialists in the textile industry, hemp fabrics are more durable and three times more extensible; they are warmer, more delicate and have high water absorption than cotton fabrics. One of Ireland’s exports from the decades to the 1930s was high-quality hemp-based underwear, while Italian hemp-based fabrics were considered one of the best textiles in the world. Hemp was also used to strengthen rotting and fire-resistant carpets, as opposed to artificial, flammable synthetics [ 69 ].
Another of the industries mentioned that uses industrial hemp is the pulp and paper industry. The first century AD saw the discovery in China that hemp paper is 50–100 times more durable than most papyrus varieties, and its production it is 100 times easier and cheaper. In the following years, this discovery spread all over the world, especially in Europe and America, where hemp paper was used to create bibles, banknotes, securities, navigation maps, logbooks, and in later years also, books and newspapers [ 83 ]. In 1776, the first declarations of independence for the United States were written on hemp paper, the popularity of which grew until the beginning of the 20th century and global industrial development. Until 1883, hemp paper accounted for most of the global paper market. Hemp has always been a significant competition in the present pulp and paper industry. Twenty to thirty percent of hemp stalks are made of hemp fiber, which is used to produce environmentally friendly paper. One hectare of hemp can produce 3–4 times more paper than the same area of trees, and the time of their growth is incomparably shorter and under favorable conditions, the harvest can take place even 3–4 times a year. Hemp paper, unlike wood pulp, does not require the clearing of long-growing, centuries-old forests that produce the oxygen necessary for life or such strong chemical processes that have a significant impact on the environment. The possibility of using recycled hemp paper is estimated at seven times, while the possibility of using wood for only three. The pulp and paper industry is one of the biggest competitors of the hemp industry, which, thanks to its political and economic influence, contributed to the introduction of the first cannabis prohibition in the United States and influenced the unfavorable perception of this plant in the world. In 1916, a method of producing hemp pulp for the production of paper was invented in the United States, using not the fibers of the stalks, as previously, but cellulose-rich fibers-shives, with four times higher efficiency, compared to wood production. The process could also use a much lower amount of sulfur and acid chemicals, and the hemp paper produced by this method does not require an environmentally harmful bleaching process. Unfortunately, no collection machines are available, and removing the outer shives from the inner fiber has not allowed this method to gain sufficient popularity. However, hemp is taking part in the production of paper again and again. As indicated in their article by Amode and Jeetah, paper production in 2018 was estimated at 400 million tons, and the annual growth each year until 2030 is forecasted at 1.1%. The data also allow the conclusion that by 2060 there will be an increase in the use of paper for printing and writing by as much as 180%. This information gives a signal that there is a need to use other sources of cellulose besides wood in the paper industry, and for environmental and ecological reasons, it will be worth increasing interest in hemp in this direction [ 84 ]. This is due to better product parameters, such as exceptional strength and mechanical and thermal resistance, resistance to abrasion and yellowing and high flexibility of the material [ 85 ].
Hemp is an extremely efficient and environmentally friendly building material. This is due to the fact that the increase in hemp biomass is two to four times greater than in forests managed on the same acreage. Hemp fiber is used to make furniture and decorations, partition plates are produced, thermal insulation of buildings is also carried out, or research is carried out on concrete blocks containing hemp fibers, characterized by low thermal conductivity and good acoustic barrier. From special varieties of hemp, it is easy to produce ecological bricks up to seven times stronger than concrete. Fiber hemp is also used to produce insulation material, building material for the construction of roofs, walls and floors. It is quite resistant to moisture, does not rot, is not flammable and is almost 100% recyclable. According to research by construction specialists, cellulose concrete made with hemp is resistant to fire and insects, is lighter than conventional building materials and has much better acoustic, thermal and insulating properties [ 86 , 87 , 88 , 89 , 90 ]. Seng et al. in their article, indicate that the thermal conductivity of hemp concrete, depending on the method, ranges from 0.103 to 0.112 W m −1 ·K −1 [ 88 ]. The use of hemp concrete reduces the cost of building a residential house thanks to the simplification of the structure and the use of cheaper raw materials. Other plant derivatives, such as hemp oil, can also be an important ingredient used in the manufacture of paints and varnishes, as it dries quickly and leaves a thin, flexible film, and the use of its subsidies in petrochemicals is eliminated.
Hemp influenced the development of the automotive industry from the very beginning. They were used in the first cars to produce structural elements. The fibers of this plant were tested as a component in the production of car bodies by Henry Ford in 1941 and by Lotus Cars. Hemp was also used to create laminates for any type of construction. Researchers dealing with the subject of hemp-containing materials postulate that hemp-based materials are extremely durable and at the same time have a high biodegradability potential. Many specialists present hemp as a natural material that is stronger than that obtained from other sources of natural cellulose fibers such as coconut, bamboo or jute. The prospect of biomaterials that make up motor vehicles is promising due to the high cost of storing old cars and a strong impact on the natural environment. The calculation of the impact of the entire product life cycle is emphasized. Hemp fiber is used to make body parts, cockpits, seats and other interior elements. On the other hand, the obtained hemp oil can be successfully used as a pro-ecological component of paints and varnishes [ 91 , 92 , 93 ].
Recently, the use of hemp derivatives in the cosmetics industry has been a very fashionable direction. Hemp oil and extracts containing regenerative, anti-aging and anti-inflammatory substances are used in the production of hemp-based cosmetics. The concentration of the four main components in industrial hemp and wild hemp varied as follows: β-caryophyllene 11–22% and 15.4–29.6%, α-humulene 4.4–7.6% and 5.3–11.9%, caryophyllene oxide 8.6–13.7% and 0.2–31.2%, and humulene epoxide 2, 2.3–5.6% and 1.2–9.5%, respectively. The concentration of CBD in the essential oil of wild hemp ranged from 6.9 to 52.4% of the total oil content, while CBD in the essential oils of registered varieties ranged from 7.1 to 25%, as described in more detail in their article by Zheljazkov et al. [ 94 ]. It is applied directly to the skin, has a protective effect, soothes inflammation, irritation and skin changes, it is recommended for people with severe allergies. Beauty salons use hemp preparations as a moisturizing and nourishing agent, reducing discoloration and evening-out skin tone. Hemp oil belongs to the so-called dry oils because it is quickly absorbed and leaves no greasy film. It can be applied directly to the skin, but today many companies produce cosmetics based on it, including care creams, lotions, massage oils, soaps, shampoos, conditioners and more. Hemp extracts largely contain cannabidiol (CBD) and resin fractions that have soothing and calming properties. The pharmaceutical and medical industries also appreciate hemp ingredients more and more. Research is being carried out on the treatment of depression, sleepiness, convulsions, degenerative diseases such as Alzheimer’s disease and nutritional problems [ 95 ]. The latest reports also indicate strong antimicrobial properties, strong Gram-positive and Gram-negative effect on drug-resistant bacteria. Preliminary information also suggests possible inhibitory effects on the growth of cancer cells [ 94 , 95 , 96 ]. Recently, there have also been reports of the biggest problem at the moment, i.e., the SARS-CoV-2 pandemic. CBD contained in hemp was used on lung epithelial cells and in mice. Cannabidiol and its metabolite 7-OH-CBD strongly block viral replication by inhibiting gene expression and reversing the effects of infection. In this case, CBD inhibits SARS-CoV-2 replication in the early stages of the disease. This relationship is therefore indicated by Nguyen et al. as a very effective potential measure to prevent infection in the early stages of infection; however, further testing and clinical trials are needed to clearly confirm the effects of cannabidiol on this virus [ 97 , 98 ].
Currently, most branches of the economy are based on polymer products, but their negative impact significantly affects the degradation of the natural environment. For this reason, research is carried out, and newer, more environmentally friendly polymer composites are introduced to the market. Such are also composites based on hemp fibers. These fibers replace the previously commonly used glass fibers with reinforcing properties [ 99 ]. However, those used so far have been energy-consuming in the production process and difficult to utilize and non-biodegradable. On the other hand, replacing them with hemp fibers allowed for the creation of more environmentally friendly composites, which, after use, have a smaller impact on the environment during storage and are also subject to partial decomposition. The most popular biocomposites are those based on resins such as unsaturated polyester, phenolic or epoxy resins. They have found their application in the production of cars, hulls of boats and small airplanes, wind turbines and other objects made with the technology of creating laminates [ 43 ]. It is also possible to use hemp oils for the synthesis of polymers, but so far, it is a poorly developed branch. A new approach indicated in the research work of Dr. Masek’s group is the use of hemp extracts and waxes in composites based on biothermoplastics and ecological vulcanizates. The hemp compounds mentioned are used as dyes, indicators of degradation processes, inhibitors and catalysts of aging processes [ 63 , 100 ].
Interesting and worth mentioning and emphasizing is the possibility of using hemp plants for the rehabilitation of mining excavations. These plants, due to their good adaptation to environmental conditions, high resistance to pests and diseases, are a great organism for pioneering introduction to damaged heaps and post-mining areas. They have good properties of binding heavy metals in their structure, which significantly allows the soil to be cleaned in a short and ecological way and enables the introduction of other species of fauna and flora to the reclaimed ecosystem [ 82 , 83 , 101 ].
The Figure 5 attached above gives a good indication of the fields in which interest in hemp plants has been greatest over the last 10 years. The top five with the highest number of publications on them are material science, engineering, agricultural and biological sciences, chemistry and chemical engineering. This analysis shows very interesting data, as the general opinion of the average consumer is that the greatest use of hemp is in cosmetology, pharmaceuticals and the medical industry, less so in the food industry. However, the data presented show that it is the industry, especially the materials industry, that has the greatest aspirations for the use of these plants in science and industry. As illustrated in Figure 6 below.
The number of occurrences of the phrase “hemp” in the Scopus database in the last 10 years, broken down into individual fields (as of 5 December 2021).
The use of hemp in various industries due to the division into the parts of the plant used.
Polymers are the most important construction material of the 20th and 21st centuries in many industries around the world. However, their cheapness and durability caused enormous havoc on the natural environment due to the deposition of huge heaps of rubbish on land and huge islands of artificial plastic seen even from space in the ratings. For this reason, the industry of biodegradable polymers and creative composites made of these polymers with natural additives has been rapidly developing in recent years. As can be seen from the above-mentioned examples of applications and the specified chemical compositions and physicochemical properties of hemp and its derivatives, these plants are an ideal candidate for a huge share in this industry sector.
Thermoplastics are currently the largest group of manufactured polymers. They have such advantages as the possibility of material, raw material or energy recycling. Over the past decades, new types of thermoplastics were developed that are made from renewable green sources and are biodegradable. Unfortunately, many of these materials do not have the required physical or chemical properties as well as conventional fossil-based thermoplastics [ 102 ]. Such conventional polymers are polypropylene (PP) and polyethylene (PE). They are characterized by durability, stiffness, lightness, good barrier properties; they are satisfactorily chemically inert, easily processable and, above all, cheap. These features make them one of the most commonly used polymers in everyday life for the production of packaging, everyday equipment and construction materials. However, these are non-biodegradable polymers; in order to increase the potential of products made of them for biodegradation and to reduce their mass proportion in the product, natural fillers are also introduced to strengthen the mechanical properties [ 103 ]. Hemp fibers can be an excellent filler in this case. This is emphasized in their work by Sullins et al. [ 104 , 105 , 106 ]. The addition of modified hemp fibers for modified hemp fibers to the PP composite increased its flexural and tensile properties. The composite with up to 30% of fibers showed better properties than pure polymer or content of 15%. Hemp fibers also showed very good interfacial interactions with this polymer matrix. On the other hand, Etaati et al., in their research, indicated changes in the analysis of dynamic mechanical properties. They investigated changes in these properties of polypropylene composites with short hemp fibers at temperatures from 25 to 150 °C. They indicate in their article that the addition of fibers strengthens the composite when working at higher temperatures, above alpha relaxation. They also emphasize that when more modifications are used in the form of a coupling agent, it is also required, which confirms the earlier statement about the necessity to modify the fibers and the composites formed with them [ 107 , 108 ]. Researcher Oliveira et al. instead dealt with PE-based composites. In her research, she showed that the treatment of hemp fibers with alkali in order to flush out lignin and hemicellulose improved the dispersion of these fibers in the matrix and improved resistance to thermal degradation. The addition of 5% modified hemp fibers and the use of a bonding agent also improved the processability during rotational molding [ 109 ]. The introduction of hemp allows lowering or eliminating voids altogether and creates stronger connections at the fiber-polymer matrix boundary, thanks to which it does not change the strength, while the modulus of elasticity increases material. Additionally, such composites characterize a more hydrophilic surface that can affect their faster degradation and thus facilitate the recycling of polyethylene-based products [ 110 ]. The most frequently used biodegradable polymer composites with hemp fibers are those based on polymers of aliphatic polyesters such as polylactide (PLA) or polyhydroxybutyrate (PHB) [ 99 , 111 , 112 , 113 ]. In the case of these polymers, the addition of hemp fibers accelerates hydrolytic degradation, which is worth mentioning that such material decomposes faster in the environment into simple compounds such as water, carbon dioxide and biomass. According to Mazzanti et al., even such a small addition of 3% wt. causes this effect [ 114 ]. As for PP and PE, also for PLA, the addition of hemp fibers significantly enhances the mechanical and thermal properties of such refined compositions. Differential Scanning Calorimetry (DSC) studies indicated that the addition of fibers did not significantly affect the glass transition and melting temperatures [ 115 ]. At this point, it is also worth emphasizing that in the case of using such a filler as hemp fibers, it depends on the orientation of the material. Arrangement parallel to the force of the fibers leads to a strong effect of transferring stresses inside the material; therefore, an important stage in the preparation of polymer composites with them is their proper orientation through the use of appropriate unit operations in the process, such as rolling, extruding, injection or calendaring. This approach allows the best possible use of the fibers as an active filler in polymer composites [ 116 , 117 ]. Apart from fibers, hemp extracts are also other additives to thermoplastic polymers. Thus far, this is a supplement with antioxidant properties. In his work, Plota et al. showed the thermally stabilizing effect of CBD on polylactide and Topas. In this case, the indicative effect of this additive is also indicated, as the color of refined samples changed with the aging processes. This is one of the few works in this direction worth exploring [ 118 ]. An equally interesting approach was shown by a team of researchers led by Andriotis et al. They created water-soluble fibers produced by the electrospun method using polyvinyl (pyrrolidine) (PVP) and Eudragit L-100, in which CBD and CBG were used as active substances with therapeutic effect [ 119 ]. Thermoplastic composites using hemp materials, as you can see, are in common use and find more and more possible applications in everyday life as well as in construction materials. It is worth continuing research on this type of material in order to increase their share in green polymer composites.
Rubbers are another important material used by humans. Due to cross-linking, unfortunately, they are not recyclable, and their natural decomposition takes hundreds of years. For this reason, it is worth delving into and developing intensively more environmentally friendly rubber compounds. In this case, hemp materials can also help us. Previous studies indicate the use of hemp derivatives in mixtures based on natural rubber (NR) [ 120 ]. From the results obtained by Moonart et al., it follows that in order to obtain good adhesion between the fiber and the polymer matrix, they must be treated. In this case, it was proposed to prepare by treating the hemp fiber with alkali and then using a KMnO 4 solution and silane. Such modification resulted in an increase in the tensile strength of the fibers and a better interfacial connection of the materials [ 121 , 122 ]. Another study investigated NR vulcanizates with hemp fibers cross-linked with benzoyl peroxide. This arrangement exhibited increased hardness, modulus at 100% elongation, tear strength, tensile strength and elongation at break. This effect depended on the degree of fiber filling of the composite. Hemp fibers can be, in this case, a good replacement for synthetic or steel fibers due to their cheapness, biodegradability and good weight-to-strength ratio [ 123 ].
Duroplasts are the last group of the polymeric materials we discuss with conspicuous additives [ 124 ]. One of the most commonly used thermosets is unsaturated epoxy resins [ 41 , 53 , 125 , 126 , 127 , 128 , 129 , 130 ]. It is this polymer that is one of the most modified with hemp derivatives. As a result of the addition of fibers, the tensile, compressive and bending strengths increased. It is logical because the fibers perfectly transfer stresses in materials in which they are active fillers. Modification by copolymerization involving the grafting of acrylonitrile on the surface of the fibers also allowed for a minimal improvement in thermal stability than in the case of unmodified hemp fibers [ 108 , 131 , 132 ]. In his article, Scarponi compared the use of glass and hemp fibers [ 133 ]. They showed that hemp/epoxy composites could compete with glass/epoxy composites. The covers for ultra-light airplanes produced for the purpose of the tests showed very good properties and, at the same time, greater environmental friendliness [ 134 ]. As indicated by previous research and theory, natural fibers require some modification to improve compatibility with the polymer matrix. In the case of combinations of hemp fibers with unsaturated polyester resin (UPE), esterification of the fibers is a good example. Such an operation allows to significantly improve the interfacial adhesion, as a result of which the chemical resistance but also the mechanical and thermal resistance of the obtained composites is improved. Another popular polymer matrix of hemp composites is polyurethanes. Members et al., in their publication, showed that the addition of hemp derivatives influenced such properties of polyurethane foams as morphology, mechanical, thermal and insulating properties. They showed in their work that impregnation with sunflower oil and tung oil resulted in improved thermal stability and flame retardancy of PUR foams. It reduced hydrophilicity by limiting water absorption [ 135 ]. Materials such as PUR are used in the construction industry to improve the thermal insulation properties of buildings. The introduction of the hemp filler brings us closer to a more sustainable development of this industry sector. Hemp fibers added to polyurethanes in the amount of 15% by weight will increase the tensile and bending modulus. Such an addition makes the product more environmentally friendly and reduces its cost [ 136 , 137 ].
This overview article shows how important cannabis has been in human history so far and what it may be in the future. The contained data illustrating the richness of the chemical composition of these plants indicates the possibility of the very wide use of active compounds in medicine, pharmacy, cosmetology and the food industry. Interest in these plants is already growing in these sectors. The use of hemp and its derivatives in the new materials sector also shows promise for the development of environmentally friendly polymer products. The polymer industry, contributing to each of the main sectors of the economy, can draw from this green source of many active phytosubstances, oils and fibers. The pro-ecological aspect of hemp cultivation, low soil and water requirements and the possibility of processing and using 100% of plants with cheap production allow us to be optimistic about the development of this production department and related science activities. There is also a lack of basic knowledge in the use of other cannabis derivatives in the polymer industry. The section dealing with elastomers is the poorest in the literature on this subject. It is a signal for researchers, technologists and entrepreneurs with a possible niche to research and use this valuable source of substances, not only fibers as a strengthening additive but also extracts and waxes as an antioxidant, antimicrobial substances, plasticizers and aging time indicators. In our opinion, scientists from around the world should intensify research on environmentally friendly materials such as hemp, which is the material of the future.
This work was completed while the second author was a doctoral candidate in the Interdisciplinary Doctoral School at the Lodz University of Technology, Poland.
AAPPH (ORAC) | Oxygen Radical Absorbance Capacity |
ABTS | 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) |
CBC | Cannabichromene |
CBD | Cannabidiol |
CBDA | Cannabinoid acid |
CBG | Cannabigerol |
CBN | Cannabinol |
C-NMR | Carbon-13 (C13) nuclear magnetic resonance |
DPPH | 2,2-diphenyl-1-picrylhydrazyl. |
FT-IR | Infrared Spectroscopy with Fourier Transformation |
NaOH | Sodium hydroxide |
THC | Delta-9-tetrahydrocannabinol |
THCV | Tetrahydrocannabivarin |
Conceptualization, formal analysis, data analysis, investigation, methodology, review and editing, A.M.; data analysis, investigation, methodology and writing, K.T.; description of results, methodology, data analysis, investigation and writing K.T.; supervisor A.M. All authors have read and agreed to the published version of the manuscript.
No external funding provided.
Not applicable.
Data availability statement, conflicts of interest.
The authors declare no conflict of interest.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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[vc_row][vc_column][vc_column_text]Paper produced entirely or mostly from the fibers of the hemp plant is known as hemp paper . Hemp or industrial hemp is the non-narcotic kin of drug cannabis or marijuana. Hemp belongs to the same plant species Cannabis Sativa L as marijuana. It’s difficult to understand how hemp paper is produced unless you understand the history of it because the method has evolved over the decades. This botanical relationship had led to hemp being outlawed in much of the world in the 20th century. Thankfully, many countries have now corrected this human blunder. Hemp has been decriminalized since it does not possess any psychoactive properties. Tetrahydrocannabinol (THC), the psychoactive element is present in high concentration in drug cannabis: 7.5 to 10 percent or higher. This gives marijuana its capacity to cause the so-called high. THC presence is limited to 0.3 percent or less in hemp, which means this plant has no psychotropic effects.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
Historians inform us that the world’s earliest paper was made by the Chinese from hemp fibers nearly 2,200 years ago around 150 BCE. It spread from China to the Middle East and then to the rest of the world. All paper used in the world was hemp paper till 1883. The first printed Bible, known as the Gutenberg Bible or the 42-line Bible, used hemp paper. Mark Twain’s novels also got printed on hemp paper. It was hemp paper that Thomas Paine used to print the leaflets that spread the idea of American independence. The first two drafts of the American Declaration of Independence were written on hemp paper. The first version of the US Constitution also got drafted on hemp paper. The current usage of hemp paper, however, is restricted mostly to specialty paper. [/vc_column_text][tm_image align=”center” md_align=”center” image=”10694″][vc_column_text]
Ancient Chinese paper
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Fibers sourced from hemp stalks are among the strongest plant fibers in tensile strength. Hemp stalks yield two types of fibers: long bast fibers and short hemp hurds or pulp fibers. Longer bast fibers come from the outer layer of the hemp stem while hemp hurds refers to the woody inner core.
It is possible to use both types of fibers for the production of hemp paper. Paper made from the long bast fibers is crumbly, thin, and coarse. Paper made from hemp hurds or pulp is thicker and softer. The production process of paper from hemp pulp is also easier.
Hemp paper like traditional paper needs the pulping of the fibers into a slurry. This is easier to do using hemp hurds. The first step is to separate the pulp from other plant matter. The next step is to soak the refined pulp in clean water and pound it to get a pulp slurry.
In industrial papermaking, some additives are used for the slurry. The next step is to remove the excess water from the slurry. The paper machine spreads the slurry on a mobile continuous screen for the water to be drained by gravity or vacuum.
Then the wet paper goes through pressing to be dried. The final outcome is a roll of paper. Cutting the rolls into different paper sizes using mechanized cutters is often a separate enterprise that paper mills do not undertake.
One of the major differences between handmade paper and industrialized paper constitutes in the edges. The machine-cut paper has smooth edges. Wooden frames called deckles are used to cut the paper into different sizes in handmade paper. That leaves the edges slightly uneven. Known as deckle-edges, they indicate that the paper is handmade.[/vc_column_text][tm_image align=”center” md_align=”center” image=”10695″][vc_column_text]
Producing handmade hemp paper
Knowing how hemp paper is made isn’t enough. You need to know the benefits.
Hemp remained the primary source of papermaking for 2000 years until wood pulp substituted it in the 20th century. The renewed interest in using hemp for papermaking is a result of a growing consciousness about several environmental hazards of using tree paper.
Hemp is nature’s solution to all the problems associated with the use of wood paper. Hemp has considerably higher renewability than trees as a source for paper. The quantity of paper generated from one acre of hemp is equal to what four to 10 acres of trees can produce over a period of 20 years.
The reason behind this productivity is the higher cellulose content in hemp stalks. Cellulose is the main ingredient of paper. Hemp stalks contain up to 85 percent cellulose in comparison to about 30 percent cellulose in wood.
The use of chemicals to remove the non-cellulose contents is significantly higher in the case of wood as nearly 70 percent of the wood is non-cellulose. Also, trees need 20 to 80 years to mature. Hemp, in contrast, is ready for use in four months.
Hemp paper is also significantly more durable than paper produced from wood pulp. It does not yellow and cracks as easily as wood paper. Ancient remnants of hemp paper testify to its durability. Hemp paper is a natural substitute for the special acid paper used for conserving important documents.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
If Mother Earth had a choice, she would choose hemp paper over wood paper. Hemp paper is far more environmentally-friendly than tree paper. Deforestation is a case in point. The world lost 502,000 square miles or 1.3 million square kilometers of forest cover between 1990 and 2016.
The National Geographic published this data quoting a World Bank report. The effects of deforestation are grim and far-reaching. It is one of the primary causes of global warming and climate change . To destroy a forest is also to release the carbon dioxide sequestered there into the atmosphere.
In addition, fewer trees imply a reduced capacity for carbon dioxide absorption. Forests are also critical for the natural water cycle to be maintained. Further, there is the loss of natural habitats for a wide range of flora and fauna. That endangers their existence and threatens the planet’s natural biodiversity.
Using hemp instead of trees for papermaking is one eco-friendly response to the problem of deforestation. In addition to reducing the need to fell trees, hemp also regenerates the soil. Paper companies planting eucalyptus after felling all the trees in an area does not compare with hemp.
Another environment-friendly aspect of hemp paper is that it needs no bleaching. The production of hemp paper thus eliminates the chances of contaminating water with dioxin or chlorine, as paper mills do. The chemicals used in separating hemp fibers from the lignin are far less toxic.
The only plant better suited for papermaking than hemp is kenaf. However, kenaf does not grow as fast as hemp and does not produce as much fiber as hemp does. Hemp has the potential to meet all our paper needs, but kenaf does not.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
Contemporary use of hemp paper is mostly limited to the production of specialty paper such as cigarette paper and cosmetic tissue paper. Only a few companies in Europe and North America have experimented with producing writing paper from hemp.
One of the reasons behind the resistance to using hemp as a source for writing paper could be the costs involved in changing the machinery. About 40 to 60 percent of retooling is necessary to switch from tree paper to hemp paper.
Gmund, a large papermill in Germany is increasingly producing large batches of hemp paper varieties, including writing paper. Other paper mills around the world need to undertake the equipment change to produce more hemp paper unless we want to be left with no more trees to fell.[/vc_column_text][/vc_column][/vc_row]
Related posts, how hemp can transform the construction ..., recycled polyester vs. recycled cotton vs ....
Recent congressional activity highlights the changing environment for cannabis regulation. Specifically, U.S. Congress is moving forward with legislation that will change the regulation of hemp-derived products. The industry could see changes as early as this fall, although it's more likely to be in the first quarter of 2025.
The Agriculture Improvement Act of 2018 (the 2018 Farm Bill) amended the Controlled Substances Act (CSA) to exclude certain products from the definition of marijuana. Specifically, the Act defines hemp as "the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts and salts of isomers, whether growing or not, with a delta-9 tetrahydrocannabinol (THC) concentration of not more than 0.3 percent on a dry weight basis."
This definition in the 2018 Farm Bill removed hemp with 0.3 percent or less of THC from the CSA, which in practice means that cannabidiol (CBD) that meets the definition of hemp is not considered a controlled substance. Although Congress' intent is generally understood to have been the legalization of hemp production (for textiles and nonintoxicating supplements) for the first time in more than a century, the 2018 Farm Bill language admittedly did not foresee the creation of the hemp-derived cannabinoid market, now conservatively valued at $28.4 billion. 1
The Farm Bill is now up for reauthorization, which happens approximately every five years. The U.S. House of Representatives' version of the 2024 Farm Bill contains language that modifies these provisions. Specifically, it now contains provisions that clarify the types of hemp cannabinoid products that would be considered lawful. The bill would redefine the existing statutory definition of hemp by replacing language basing the legal limits for hemp on its delta-9 tetrahydrocannabinol (delta-9 THC) concentration and instead basing the definition on hemp's "total tetrahydrocannabinol (including tetrahydrocannabinol acid (THCA]) [Total THC] concentration." Other statutory language regarding hemp "derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers, whether growing or not" would remain unchanged.
In addition, at the House Committee on Agriculture's late-May markup of the Farm Bill reauthorization language, an amendment was passed that changed the definition of hemp in federal law to only include naturally occurring, naturally derived and nonintoxicating cannabinoids. (See Holland & Knight's previous alert, " House Agriculture Committee Completes Markup of 2024 Farm Bill ," May 28, 2024.) The bill as amended does not define "intoxicating," however, it would prohibit hemp cannabinoid products with "quantifiable amounts" of Total THC (including THCA) or any other cannabinoids that have (or are marketed to have) "similar effects on humans or animals" as THC, as determined by the U.S. Department of Agriculture (USDA).
Although the U.S. Senate version of the 2024 Farm Bill has not yet been released, it is clear Congress is looking to resolve, in some fashion, issues related to THC production resulting from the 2018 Farm Bill.
The Agriculture-FDA Appropriations legislation for fiscal year 2025 also contains language addressing hemp. The House bill contains language similar to the 2024 Farm Bill proposals that further refines the federal definition of hemp to only include naturally occurring, naturally derived and nonintoxicating cannabinoids and excludes those with "quantifiable amounts" of Total THC.
The recently released Senate version of the Agriculture-FDA funding bill contains no provisions related to hemp and cannabinoids. The full Senate will vote on the bill in the coming weeks. Provisions could be added when the bill is debated by the full Senate, but the most likely outcome is that House and Senate negotiators will work toward finding a solution before final passage this year.
Congressional action on the Farm Bill and the appropriations process are significant because they become effective upon enactment – which could be as early as this fall. Thus, they will become legally binding before the U.S. Drug Enforcement Agency (DEA) publishes its final regulation on the rescheduling of marijuana.
Holland & Knight will continue to closely monitor these developments. Please contact the authors for more information.
1 2023 U.S. National Cannabinoid Report , Whitney Economics
Information contained in this alert is for the general education and knowledge of our readers. It is not designed to be, and should not be used as, the sole source of information when analyzing and resolving a legal problem, and it should not be substituted for legal advice, which relies on a specific factual analysis. Moreover, the laws of each jurisdiction are different and are constantly changing. This information is not intended to create, and receipt of it does not constitute, an attorney-client relationship. If you have specific questions regarding a particular fact situation, we urge you to consult the authors of this publication, your Holland & Knight representative or other competent legal counsel.
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Impact hub case studies: cross-sector institutions solving public problems, apopo, singapore’s alliances for action, and the guinea worm eradication program, policy paper.
In an effort to support policymakers and civic entrepreneurs around the world, New America and the Chandler Institute of Governance in Singapore are conducting research to better understand the features of cross-sector institutions that can solve public problems.
One model is an Impact Hub, a type of institution that brings together diverse partners to address a specific, clearly defined policy challenge. Impact Hubs pool the expertise, resources, and networks of partners from the public, private, and civic sectors. They implement concrete solutions and use metrics to track outcomes. The Impact Hub Field Guide describes their features in detail and the steps for shaping one.
Several hubs are already operating at the global, national, and local levels all over the world. A new collection of case studies examines three of these hubs in depth: APOPO, Singapore’s Alliances for Action, and the Guinea Worm Eradication Program.
In order to reduce civilian harm from the millions of landmines in post-conflict zones all over the world, APOPO , a Belgian-based nonprofit, implemented a novel, cost-effective method: trained scent-detection rats. To find both landmines and cases of tuberculosis, the organization used an innovative operational model based on local partnerships, technological innovation, and community engagement to deploy rats at scale and save thousands of lives.
In order to develop and implement solutions to a range of local challenges, the Singaporean government partnered with companies, civil society organizations, and citizens to create Alliances for Action (AfA). These time-bound, results-based initiatives built civic ties and made measurable progress on issues ranging from environmental protection to online harms.
The Guinea Worm Eradication Program (GWEP) brought together partners ranging from presidents to village elders to prevent the spread of the Guinea Worm disease, a painful, debilitating ailment that affects people in some of the world’s most isolated and lowest-income areas. In 1986, when the Carter Center, a U.S. nonprofit organization, started its initiative to address the disease, 3.5 million people suffered from it. In 2023, the world recorded only 14 cases, with the disease on the verge of being only the second ever to be eradicated (after smallpox in 1980).
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Case Studies in Chemical and Environmental Engineering. Volume 9, June 2024, 100550. ... In this context, we systematically reviewed 101 reviews and 655 research papers on hemp to map what we already know and what we still need to know about hemp, across its supply chain; from cultivar selection through production to end use. ...
According to the study on different pulping methods of hemp bast fiber, it is found quite acceptable in place of wood from the technical point of view, and even woody cores can also be a promising raw material for paper. Hemp pulps are generally used by mixing with wood pulp, and currently, 100% hemp paper production is not seen [41]. Hemp is ...
Similarly to its main component, the CF of LHC varies across regions [] (Table 2).Most LCA studies have also reported that LHC has the potential to be a carbon negative material [18,20,21,29,30,31], and highlight the production of lime-based binders as a hotspot during its life cycle [9,32,33].Moreover, when large amounts of lime-based binders are used, the resultant material tends to be ...
State of the art: studies on hemp in the b uilding sector Several studies r elated to hem p - based products employed in the bui lding sector were carried out during the last 15 years.
2024, Case Studies in Chemical and Environmental Engineering. Show abstract. ... In this context, we systematically reviewed 101 reviews and 655 research papers on hemp to map what we already know and what we still need to know about hemp, across its supply chain; from cultivar selection through production to end use. ...
As is the case for many other industrial plant species, hemp economics is complex. ... which it is grown and refined; it can be a carbon neutral or carbon negative plant, depending on these methods. In one study, hemp straw grown on a 2.47-acre field ... D.G. Industrial Hemp as an Alternative Crop in North Dakota: A White Paper Study of the ...
Hemp concrete is a lightweight concrete that is currently only being used as an in-fill material. in non-structural applications (see Figure 2). In European countries it is normally cast in ...
Familiarity with hemp paper has risen from 35.0% in 2019 to 61.6% in 2020. General use of hemp-based products has risen from 32.6% in 2019 to 54.7% in 2020. ... Through a case study of Vermont residents, results offer a reference for consumer response and behavior toward hemp in the first year of federal legalization.
this paper will be implemented with periodical tests to study the evolution of the performances of the material and its durability in residential structures. The main concern about the durability of hempcrete is determined by the presence of vegetal material because the variation of moisture conditions can cause its degradation. Thus, a
Department of Textiles and Consumer Sciences. Tel: (850) 644 -8078, Fax: (850) 645-4673. E -mail: [email protected]. ABSTRACT. Objectives of this paper are to discuss hemp within the ...
The ecofriendly or green revolution has greatly evolved, especially from a marketing perspective. Hemp products, especially food protein and non-food products (paper) may well be the next evolution ecofriendly supply chain strategies. Through the use of a case study approach, hemp as a source for paper that results in a quicker cycle time and is more climate change friendly than trees, may ...
A 2021 case study of CBD-rich hemp extract revealed 93.5% average increase in hair regrowth. Hemp extract works through the endocannabinoid system (ECS) in the body and has novel effects on hair follicle elongation and hair matrix keratinocytes activated through ECS receptors in the hair follicle cells. As such, the therapeutic effects of hemp ...
Sustainable construction materials, environmentally friendly materials, hemp, and hempcrete were used as keywords for literature research. For the research paper, papers published from the past 10 to 15 years with a few older studies were also included. various articles, YouTube videos and journals were also being considered for the same.
This study describes what is known about the economic and regulatory considerations of U.S. hemp agriculture through the lens of path dependency, and important questions remain regarding the legal and regulatory landscape of hemp, and are further complicated by its current listing as a Schedule 1 drug. The Agricultural Act of 2014 allowed for federally funded research on hemp for the first ...
Click on the button or image to read and download the IHBA Position Paper from February 2022 on The Appropriate Measurement of Hemp and Other Natural Building Material Performance. Download. Other resources on hemp building. Print Book. Hemp Buildings: 50 International Case Studies . by Steve Allin, order the book from the Seedpress website ...
Hemp products, especially food protein and non-food products (paper) may well be the next evolution ecofriendly supply chain strategies. Through the use of a case study approach, hemp as a source for paper that results in a quicker cycle time and is more climate change friendly than trees, may well turn out to be a part of a sustainable supply ...
Until 1883, hemp paper accounted for most of the global paper market. Hemp has always been a significant competition in the present pulp and paper industry. ... In this case, hemp materials can also help us. Previous studies indicate the use of hemp derivatives in mixtures based on natural rubber (NR) . From the results obtained by Moonart et ...
Hemp concrete is a "carbon-negative" or "better-than-zero-carbon" substance because the hemp plant absorbs more carbon from the atmosphere than it emits during its production and application on site. It is a bio-composite material that can be utilised as an alternative to concrete and standard insulation in building.
According to the study on different pulping methods of hemp bast fiber, it is found quite acceptable in place of wood from the technical point of view, and even woody cores can also be a promising raw material for paper. Hemp pulps are generally used by mixing with wood pulp, and currently, 100% hemp paper production is not seen
Papers focused specifically on hemp fiber, like the influence of weave patterns and features (Corbin et a l., 2020), have enab led introduction into the industry. Th at being said, U S pilot studies
Paper made from the long bast fibers is crumbly, thin, and coarse. Paper made from hemp hurds or pulp is thicker and softer. The production process of paper from hemp pulp is also easier. Hemp paper like traditional paper needs the pulping of the fibers into a slurry. This is easier to do using hemp hurds.
This paper presents a review of the state-of-the-art of hemp concrete research, with a view to identifying research gaps that shall guide future research for its implementation in the fast-growing green buildings industry. ... no larger than 40 ± 5 mm in their largest dimension. Sinka et al. (2014) in their studies had used hemp hurds having ...
Case Studies. View All Matching Results; July 26, 2024. Congress Advances Cannabis and Hemp Proposals. ... Substances Act (CSA) to exclude certain products from the definition of marijuana. Specifically, the Act defines hemp as "the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts ...
In an effort to support policymakers and civic entrepreneurs around the world, New America and the Chandler Institute of Governance in Singapore are conducting research to better understand the features of cross-sector institutions that can solve public problems.. One model is an Impact Hub, a type of institution that brings together diverse partners to address a specific, clearly defined ...