Towards a better understanding of the links between the composition and mechanical properties of hemp fibers
Topic(s) : Material science
Co-authors :
Antoine BOZEK (FRANCE), Johnny BEAUGRAND (FRANCE), Fabienne MATHIS (FRANCE), Laurent GUILLAUMAT , Armel MEWOLI (FRANCE)Abstract :
Nowadays, composite materials are reaching a pivotal moment. They must adapt to ecological challenges while maintaining their economic attractiveness and specific properties. Amid the different developments in the composite materials field, natural fibers composites (NFC) are highlight for their ecological and economic interests. Partially produced from biomass, they generally permit to lower the economical global cost while reducing the human footprint, aiming to design a cheaper and more ecofriendly final product. To date, the heterogeneity of the initial raw materials limiting their industrials productions. Among annual fibers, Hemp (Cannabis Sativa L.) is a promising crop for industrial applications in many industrial fields, including materials. The main qualities of this plant are its resistance to water stress and lower demands for inputs (fertilizers in particular) than other plants such as flax. In addition, it can be harvested on so-called marginal lands, not suitable for food agriculture. [1] Production of hemp for industries can focus on improving the quality and yield of its fibers, aiming to be use as reinforcement, replacing synthetic ones, such as glass or carbons. [2] However, the disparities of the biocomposition and structure (Cellulose microfibrillar angle, diameter of the lumen) of the technical fibers leads to contrast mechanical behavior, even in a same genotype, and have to be further study.
This presentation will focus on the links between genetics criteria and tensile mechanical properties, with a particular attention on the fibers elements polymers composition and its impact on the properties. Among the biocomposition, lignin, monosaccharides and proteins contents have been measured by different analytical chemistry methods (respectively Absorption Spectroscopy, Gas Chromatography, and Elemental Analysis). The mechanical properties have been studied on bundles of fibers of seven centimeter, to emphasize the properties of the matrix (the middle lamella) connecting the fibers together and excluding the probability to break one individual fiber at both extremities. Young’s modulus and tensile strength have been measured (Figure 1). Thus, statistical correlation has been calculated to estimate which biopolymer impact the most the mechanical properties of the bundle alone, before using them in natural fiber composites materials. It has permit to highlight biopolymers of interest for the breeding of genotypes, and the impact of the lignin, proteins and monosaccharides content on the final properties of fibers. It also underlining the heterogeneity of the crop and the technical fibers within a same genotype.
This presentation will focus on the links between genetics criteria and tensile mechanical properties, with a particular attention on the fibers elements polymers composition and its impact on the properties. Among the biocomposition, lignin, monosaccharides and proteins contents have been measured by different analytical chemistry methods (respectively Absorption Spectroscopy, Gas Chromatography, and Elemental Analysis). The mechanical properties have been studied on bundles of fibers of seven centimeter, to emphasize the properties of the matrix (the middle lamella) connecting the fibers together and excluding the probability to break one individual fiber at both extremities. Young’s modulus and tensile strength have been measured (Figure 1). Thus, statistical correlation has been calculated to estimate which biopolymer impact the most the mechanical properties of the bundle alone, before using them in natural fiber composites materials. It has permit to highlight biopolymers of interest for the breeding of genotypes, and the impact of the lignin, proteins and monosaccharides content on the final properties of fibers. It also underlining the heterogeneity of the crop and the technical fibers within a same genotype.