Industrial hemp (Cannabis sativa) is one of the most available and widely produced bast fibers with high cellulose content. Interest in these fibers is warranted due to environmental protection challenges as well as their inherent properties such as low density, high specific strength, and stiffness. In addition, advanced research and progress have gone into increasing their mechanical performance through surface treatments and in the development of new materials. The most promising application for hemp fibers is as reinforcement in polymeric composites or through hybridization. Nonetheless, more research is needed to improve their properties and expand their range of applications. The biodegradability issue is one problem that must be addressed when considering long life-cycle applications as the reproducibility of these composites’ final properties. This review is a comprehensive literature review on hemp fibers. It includes hemp fibers’ chemical and mechanical properties, surface modifications, hybrid composites, as well as current and future applications.

https://www.mdpi.com/2079-6439/7/12/106/pdf

Industrial Hemp Fibers: An Overview

Effects of interphase regions and filler networks on the viscosity of PLA/PEO/carbon nanotubes biosensor

Mechanical, wear, and drop load impact behavior of glass/Caryota urens hybridized fiber‐reinforced nanoclay/SiC toughened epoxy multihybrid composite

Toward sustainability of polymer-matrix composites, this study aimed to prepare and evaluate glass fiber reinforced (GFR) biocomposites of fully bio-based furan resin, and their partial comparison with those from resole phenolic resin used commonly in composite industry. Thus, the bioresin, poly(furfuryl alcohol), PFA, was synthesized using a sulfonic acid catalyst. A furan biocomposite with a woven glass fiber (GF), modified by (3-aminopropyl)-triethoxysilane, and various percentages of talc filler were prepared. The mechanical properties of the GFR composite specimens were studied using three-point bending test, tensile test, and dynamic mechanical thermal analysis. Flexural strength was enhanced from 202 to 240 MPa by employing modified fibers, while using 1, 3 and 5 wt% of talc, it reached to 235, 252 and 228 MPa, respectively. Simultaneous use of the modified fibers and 3 wt% of talc significantly improved the flexural strength up to 327 MPa. The scanning electron microscope images evidently confirmed an increase in fiber-matrix adhesion in bioresins with modified fibers and talc. Thermogravimetric analysis established a promotion of thermal properties as a result of the apparent initial decomposition temperature, which was more obvious for the modified fiber containing biocomposites. Finally, the superiority of the bioresin was proved by comparing it to its petro-based counterpart in acidic, basic, and organic solvents. Thus, in many common uses, the inexpensive sustainable PFA bioresin can be considered as a promising alternative to a non-sustainable phenolic resin originated from petroleum resource.

Alessandra Maino

Papers

Glass/Epoxy and Hemp/Bio based epoxy composites: Manufacturing and structural performances