“The construction industry is facing increased demand for adopting sustainable ‘green’ building materials to minimise the carbon footprint of the infrastructure sector to meet the United Nations 2030 Sustainability Goals.

Natural bio-composite materials such as timber and bamboo have been widely used in construction for centuries. Hemp has also been used in different forms in the construction sector for decades for its thermal and acoustic insulation capability owing to its moisture buffering capacity and thermal conductivity.

The current research aims to explore the possible application of hydrophilic hemp shives for assisting the internal curing of concrete materials as a biodegradable alternative to currently used chemical products.

The properties of hemp have been assessed based on their water absorption and desorption properties associated with their characteristic sizes.

It was observed that, in addition to its excellent moisture absorption capacity, hemp released most of its absorbed moisture into the surroundings under a high relative humidity (>93%); the best outcome was observed for smaller hemp particles (<2.36 mm).

Furthermore, when compared to typical internal curing agents such as lightweight aggregates, hemp showed a similar behaviour in releasing its absorbed moisture to the surroundings indicating its potential application as a natural internal curing agent for concrete materials.

An estimate of the volume of hemp shives required to provide a similar curing response to traditional internal curing techniques has been proposed.”

https://pubmed.ncbi.nlm.nih.gov/37297126

https://www.mdpi.com/1996-1944/16/11/3993

“There has been increasing interest in green and recyclable materials to promote the circular economy. Moreover, the climate change of the last decades has led to an increase in the range of temperatures and energy consumption, which entails more energy expenditure for heating and cooling buildings.

In this review, the properties of hemp stalk as an insulating material are analyzed to obtain recyclable materials with green solutions to reduce energy consumption and reduce noise to increase the comfort of buildings.

Hemp stalks are a low-value by-product of hemp crops; however, they are a lightweight material with a high insulating property.

This study aims to summarize the research progress in materials based on hemp stalks and to study the properties and characteristics of the different vegetable binders that could be used to produce a bio-insulating material. The material itself and its microstructural and physical aspects that affect the insulating properties are discussed, as is their influence on durability, moisture resistance, and fungi growth.

Research suggests using lignin-based or recyclable cardboard fiber to develop a bio-composite material from hemp stalk, but long-term stability requires further investigation.”

https://pubmed.ncbi.nlm.nih.gov/37110081

“According to the results presented in the different studies of the last decades, hemp is positioned as a green material with great insulating properties that could replace some inorganic commercial materials to improve the insulating performance of buildings and build green buildings.”

https://www.mdpi.com/1996-1944/16/8/3245

“We investigated the thermal conductivity of materials based on pyrolysis temperature, filler loading, filler size, and type of biomass feedstock.

Hemp stalk and switchgrass were pyrolyzed at 450, 550, and 650 °C and crushed into 50, 75, and 100 μm particle sizes. Biocarbon fillers (10, 15, and 20 wt %) were added to the bioepoxy polymer matrix.

The study showed increased filler loading and particle size increased thermal conductivity-the biocomposite samples with 20 wt % filler loading of 100 μm particle size of the biocarbon obtained at 650 °C showed the maximum thermal conductivity in both hemp biocarbon-filled composites (0.59 W·m^-1·K^-1) and switchgrass-filled composites (0.58 W·m^-1·K^-1) with the highest flame time. Biocarbon in biofiber-reinforced polymer composites can improve thermal conductivity and extend the flame time.

These findings significantly contribute to developing hemp-based bioepoxy composite materials for thermal applications in various fields. These include insulating materials for buildings and thermal management systems, energy-efficient applications, and help in material selection and product design with a positive environmental impact.”

https://pubmed.ncbi.nlm.nih.gov/37151540

“These novel composite materials will likely be increasingly important in sustainable manufacturing and construction processes. Using sustainable and renewable materials like hemp and biocarbon aligns with the trend toward eco-friendly and green manufacturing practices.”

https://pubs.acs.org/acsodf/article/8/17/15422/343646/Thermal-Response-of-Biocarbon-Filled-Hemp-Fiber

“The present work aims to develop thermosetting resins using epoxidized hemp oil (EHO) as a bio-based epoxy matrix and a mixture of methyl nadic anhydride (MNA) and maleinized hemp oil (MHO) in different ratios as hardeners.

The results show that the mixture with only MNA as a hardener is characterized by high stiffness and brittleness. In addition, this material is characterized by a high curing time of around 170 min. On the other hand, as the MHO content in the resin increases, the mechanical strength properties decrease and the ductile properties increase.

Therefore, it can be stated that the presence of MHO confers flexible properties to the mixtures. In this case, it was determined that the thermosetting resin with balanced properties and high bio-based content contains 25% MHO and 75% MNA. Specifically, this mixture obtained a 180% higher impact energy absorption and a 195% lower Young’s modulus than the sample with 100% MNA.

Also, it has been observed that this mixture has significantly shorter times than the mixture containing 100% MNA (around 78 min), which is of great concern at an industrial level. Therefore, thermosetting resins with different mechanical and thermal properties can be obtained by varying the MHO and MNA content.”

https://pubmed.ncbi.nlm.nih.gov/36987185

“After compiling all the data obtained, it can be concluded that maleinized hemp oil (MHO) is an excellent crosslinking agent next to methyl nadic anhydride (MNA), which is of petrochemical origin, for epoxidized hemp oil (EHO).

After performing the mechanical tests, it was observed that the sample containing 100% MNA (100MNA) presented with high rigidity and brittleness, whereas, with the addition of MHO in different amounts, it was observed that the material showed greater ductility and flexibility.”

https://www.mdpi.com/2073-4360/15/6/1404

“In this study, hemp seed oil was reacted with maleic anhydride in an ene reaction to obtain maleinized hemp seed oil (MHO).

The use of MHO as a plasticizer and compatibilizer has been studied for polylactic acid (PLA) and thermoplastic starch (TPS) blends (80/20, respectively). By mechanical, thermal and morphological characterizations, the addition of MHO provides a dual effect, acting as plasticizer and compatibilizer between these two partially miscible biopolymers.

The addition of MHO up to 7.5 phr (parts by weight of MHO per hundred parts of PLA and TPS) revealed a noticeable increase in the ductile properties, reaching an elongation at break 155% higher than the PLA/TPS blend. Furthermore, contrary to what has been observed with maleinized oils such as linseed oil, the thermal properties do not decrease significantly as a result of the plasticizing effect, due to the compatibilizing behavior of the MHO and the natural antioxidants present in the oil.

Finally, a disintegration test was carried out in aerobic conditions at 58 °C, for 24 days, to demonstrate that the incorporation of the MHO, although causing a slight delay, does not impair the biodegradability of the blend, obtaining total degradation in 24 days.”

https://pubmed.ncbi.nlm.nih.gov/33922939

“MHO is shown to be a potential plasticizer and compatibilizer of organic origin, to be used in different polymeric blends without affecting their biodegradability.”

https://www.mdpi.com/2073-4360/13/9/1392

“Hempseeds, the edible fruits of the Cannabis sativa L. plant, were initially considered a by-product of the hemp technical fibre industry. Nowadays, following the restorationing of the cultivation of C. sativa L. plants containing an amount of delta-9-tetrahydrocannabinol (THC) <0.3% or 0.2% (industrial hemp) there is a growing interest for the hempseeds production due to their high nutritional value and functional features.

The goal of this review is to examine the scientific literature concerning the nutritional and functional properties of hempseeds. Furthermore, we revised the scientific literature regarding the potential use of hempseeds and their derivatives as a dietary supplement for the prevention and treatment of inflammatory and chronic-degenerative diseases on animal models and humans too.

In the first part of the work, we provide information regarding the genetic, biochemical, and legislative aspects of this plant that are, in our opinion essential to understand the difference between “industrial” and “drug-type” hemp. In the final part of the review, the employment of hempseeds by the food industry as livestock feed supplement and as ingredient to enrich or fortify daily foods has also revised.

Overall, this review intends to encourage further and comprehensive investigations about the adoption of hempseeds in the functional foods field.”

https://pubmed.ncbi.nlm.nih.gov/32610691

“Overall, the studies performed on animal models have highlighted that there is some evidence about the protective and beneficial effects of hempseeds dietary supplementation especially on inflammatory and chronic-degenerative diseases such as CVDs and neurodegenerative ones, whereas, from the human studies some benefits for the atopic dermatitis treatment, certain blood parameters, and inflammatory responses modulation were emerged following the hempseed oil dietary intake.”

https://www.mdpi.com/2072-6643/12/7/1935

“Hemp seed (Cannabis sativa L.) contain large amounts of nutrients, e.g. protein, dietary fiber, minerals, and unsaturated fatty acids, which make them a good fortifying component in food production.

The aim of the present study was to determine the effect of hemp addition on the physicochemical properties, cooking quality, texture parameters and sensory properties of durum wheat pasta. The samples were fortified with 5-40% of commercially available hemp flour or 2.5-10% of hemp cake obtained from hemp seed oil pressing.

Our study showed that the addition of hemp seed raw materials led to an increase in the protein, total dietary fiber (TDF), ash and fat content in the pasta samples.

Due to its lower granulation and higher nutritional value, hemp flour was found to be a better raw material for the fortification of pasta than hemp cake. Pasta enriched with hemp flour at the level of 30-40% contains 19.53-28.87% d.m. of protein and 17.02-21.49% d.m. of TDF and according to the EU, a definition can be described as a high-protein and high-fiber products.

All enriched pasta samples were also characterized by safe Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content, and their sensory properties were accepted by consumers.”

https://pubmed.ncbi.nlm.nih.gov/33735229

“Consumers are looking for new plant-based raw materials that could be a good source of protein. One of the high-protein raw materials, which is increasingly becoming part of a healthy balanced human diet is hemp (Cannabis sativa L.).”

“Hemp seeds are a rich source of nutrients.”

“The results of the research indicate the possibility of using hemp components to improve the nutritional value of pasta while maintaining its safety.

Both hemp raw materials allow enriching pasta with protein, dietary fiber, mainly its insoluble fraction and minerals.

Pasta with 30% addition of hemp flour can be described as a high-protein and high-fiber product and at the same time characterized by satisfactory organoleptic properties and good cooking qualities.”

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248790