Natural fiber reinforced polymer composites play important roles in the production of eco-friendly materials because of their high modulus, meticulous strength and reduced carbon footprint on the environment. Coconut (cocos nucifera) is cultivated extensively in tropical countries for its fruits whereas the husks and shells are mostly disposed as waste. These portions of the coconut plant serve as potential resource for natural fibers which are used to reinforce polymer composites. This work gives an overview of current knowledge of coir fiber and coir fiber reinforced polymer composites. The preparation and production of different matrices reinforced with coir fibers and the mechanical structural and thermal properties of these composites have been studied by several researchers and are elucidated in this review. The major treatment techniques used to modify coir fibers were also discussed.

A review of coir fiber reinforced polymer composites

In the time of rapidly depleting petroleum resources, worldwide food shortages, and solid waste problems, it is imperative to promote dedicated research into using an appropriate pretreatment technique utilizing regeneratable raw materials such as lignocellulosic biomass. However, not all pretreatment techniques are viable alternatives for industrial practice. Pretreatment is an important step to upgrade different kinds of lignocellulosic biomass into more valuable products, including biofuels and bio-based industrial chemicals. Most of the pretreatment techniques have their limitations or weaknesses, including high operational costs and temperature, toxicity and corrosiveness to the instrument, etc., while, some other pretreatment methods such as biological and plasma pretreatment are green procedures that can also be used to alter the physical and chemical properties of lignocellulosic materials. Although our present understanding is still low and not much research has been done to guarantee which pretreatment method is the reliable alternative, the combination of different pretreatment methods could be a good strategy to overcome the limitations of each approach. This review presents an overview of different pretreatment methods of lignocellulosic biomass to increase the rate and the degree of cellulose hydrolysis and subsequent processing steps as well as future perspectives.

Pretreatment and fermentation of lignocellulosic biomass: Reaction mechanisms and process engineering

Mechanical properties of bamboo fiber-reinforced polymer composites: a review of recent case studies

The aim of this paper was to review the recent advances in treatment strategies for natural fibers before their utilization in a reinforced composite in the last 5 years. More focus was placed on e...

An empirical review of the recent advances in treatment of natural fibers for reinforced plastic composites

Flexural response of 3D printed sandwich composite

In this study, jute fabrics/epoxy-laminated composites were fabricated via a simple and effective manual layering. Hot-alkali treatment was used to pretreat jute fabrics to improve their interfacial compatibility. The effects of hot-alkali treatment with five concentrations (2%, 4%, 6%, 8% and 10%) on the composition, crystallinity and surface morphology of jute fibers, were analyzed with the aids of Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and the scanning electron microscope (SEM). The mechanical properties (tensile and flexural) of laminated composites, and the morphology of the tensile fracture surface, were analyzed. The results indicated that the crystallinity index (CI) and crystallite size (CS) of the cellulose in jute fibers were improved, and there were three stages for CI and CS with the increase of alkali concentrations. Hot-alkali treatment improved the mechanical properties of laminated composites, especially for the 6% NaOH-treated jute fabric reinforced. The tensile strength, flexural strength, tensile modulus and flexural modulus of 6% NaOH-treated fabrics reinforced composites were enhanced by 37.5%, 72.3%, 23.2% and 72.2%, respectively, as compared with those of untreated fabrics reinforced composites. The fiber pull-out and the gaps of the tensile fracture surface were reduced after hot-alkali treatment.

Xue Wang

Papers

Effect of Hot-Alkali Treatment on the Structure Composition of Jute Fabrics and Mechanical Properties of Laminated Composites

Bending behaviors of three grid sandwich structures with wood facing and jute fabrics/epoxy composites cores