Renewable and sustainable biobased materials: An assessment on biofibers, biofilms, biopolymers and biocomposites

Demands for reducing energy consumption and environmental impacts are the major driving factors for the development of natural fiber–reinforced composites (NFRCs) in many sectors. Compared with synthesized fiber, natural fiber provides several advantages in terms of biodegradability, light weight, low price, life-cycle superiority, and satisfactory mechanical properties. However, the inherent features of plant-based natural fibers have presented challenges to the development and application of NFRCs, such as variable fiber quality, limited mechanical properties, water absorption, low thermal stability, incompatibility with hydrophobic matrices, and propensity to agglomeration. Substantial research has recently been conducted to address these challenges for improved performance of NFRCs and their applications. This article reviews the recent advancements of plant-based NFRCs, focusing on strategies and breakthroughs in enhancing the NFRCs’ performance, including fiber modification, fiber hybridization, lignocellulosic fillers incorporation, conventional processing techniques, additive manufacturing (3D printing), and new fiber source exploration. The sustainability of plant-based NFRCs using life-cycle assessment and the burgeoning applications of NFRCs with emphasis on the automotive industry are also discussed.

Recent advancements of plant-based natural fiber–reinforced composites and their applications

Mechanical properties evaluation of sisal fibre reinforced polymer composites: A review

Fused deposition modeling (FDM) has gained much attention in recent years, as it revolutionizes the rapid manufacturing of customized polymer-based composite components. To facilitate the engineering applications of these FDM-printed components, understanding their basic mechanical behaviors is necessary. In this paper, the mechanical characteristics, including tensile and flexural properties of samples fabricated by FDM with different additives, i.e. wood, ceramic, copper, aluminum and carbon fiber, based polylactic acid (PLA) composites are comprehensively investigated. The effects of different PLA composites, build orientations and raster angles on mechanical responses are compared and analyzed in detail. It is found that ceramic, copper and aluminum-based PLA composite parts have similar or even increased mechanical properties compared with virgin PLA made parts. In most cases, PLA composite samples that are FDM-printed in on-edge orientation with +45°/−45° raster angles have the highest mechanical strength and modulus. It is worth noting that the results in this research provide a useful guideline for fabricating complex functional PLA composite components with optimized mechanical properties.

Mechanical characteristics of wood, ceramic, metal and carbon fiber-based PLA composites fabricated by FDM

Environment friendly, renewable and sustainable poly lactic acid (PLA) based natural fiber reinforced composites – A comprehensive review

The processing strategy adopted to develop biocomposites plays a significant role in determining their characteristics. The present experimental investigation explores the feasibility of using direct-injection molding (D-IM) process for processing of sisal fiber (3 mm and 8 mm) reinforced poly-lactic acid biocomposites with a fiber weight fraction of 30%. For a comparative analysis, mechanical and morphological behavior of biocomposites developed using D-IM process is compared with biocomposites developed using extrusion-injection molding (E-IM) process. The mechanical behavior in terms of tensile, flexural and impact properties is compared and discussed in relation to extracted fiber morphology and fiber orientation as well as dispersion within the developed biocomposites. Morphological investigation of extracted fibers revealed severe fiber attrition and fiber length variation during E-IM process as compared with D-IM process. However, short sisal fiber (3 mm) reinforced biocomposites developed ...

Processing of PLA/sisal fiber biocomposites using direct- and extrusion-injection molding

This study presents the recyclability analysis of PLA/Sisal biocomposites comprising sodium bicarbonate treated Sisal fibers (30 wt%). The biocomposites were recycled (8 times) using the extrusion process. The tensile strength of injection molded biocomposites declined by 20.9% up to the third recycle. The dynamic mechanical analysis revealed a severe reduction in storage and loss modulus beyond third recycle. The morphological and thermal characterization of recycled biocomposites also revealed severe fiber and matrix degradation. The infrared spectroscopy exhibited hydrolysis as one of the causes of PLA degradation after recycling. The recycling of PLA/Sisal biocomposites beyond third recycle is not recommended. However, the biocomposites recycled up to third recycle can be used for making products for low to medium strength non-structural applications.

Recyclability analysis of PLA/Sisal fiber biocomposites

This research endeavor explores the effect of economical and environment-friendly treatment of sisal fibers, prior to their incorporation into poly-lactic acid (PLA). Biocomposites incorporating sisal fibers (30% [w:w]) treated with sodium bicarbonate (10% [w:v]) aqueous solution for varying time periods (24, 72, 120, and 168 h) were developed using extrusion-injection molding process. Thermogravimetric analysis, morphological examination, Fourier-transform infrared spectroscopy, and lignocellulosic composition analysis of raw and treated sisal fibers established a gradual removal of hemicellulosic content from fiber surface with increasing treatment time. Biocomposites incorporating sisal fibers treated for 72 h exhibited optimum tensile, flexural, and compressive properties. While in case of impact testing, biocomposites incorporating sisal fibers treated for 24 h exhibited maximum impact strength. The optimum results were found comparable to sodium hydroxide treated sisal fiber-reinforced biocomposites. Hence, considering commercialization of biocomposites, sodium bicarbonate treatment offers huge potential to substitute ecologically hazardous sodium hydroxide treatment ensuring good mechanical properties. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

Sisal fiber-reinforced green composites: Effect of ecofriendly fiber treatment

Green Composites (Biocomposites) comprising of lignocellulosic fibers are low cost sustainable materials having huge potential to replace petroleum derived commodity and engineering plastics. In order to improve the interfacial interaction with the matrix, lignocellulosic fibers are subjected to fiber surface modification. The present research endeavor aims to explore the use of ecofriendly fiber surface treatment in order to limit the environmental hazards of conventionally used chemical treatments. Fiber surface modification of Aloe Vera fibers prior to their incorporation into PLA based biocomposites was done using an aqueous solution of sodium bicarbonate (10% (w: v)). FTIR spectroscopy, thermal analysis, lignocellulosic composition, single fiber strength and fiber morphology were examined to ascertain the effect of varying treatment time (24, 48, 72, 120 and 168 hours) on the fiber characteristics. The biocomposite test specimens were developed using Extrusion-Injection molding process. An optimum fiber treatment time of 72 hours exhibited highest improvement in tensile, flexural and compressive behavior of the developed biocomposites. The biocomposites incorporating treated (72 hours) Aloe Vera fibers exhibited 104.9% higher impact strength as compared to neat PLA. Hence, the use of sodium bicarbonate treatment for lignocellulosic-fiber surface modification ensures greener and safer processing of biocomposites without compromising their mechanical properties.

Ecofriendly treatment of aloe vera fibers for PLA based green composites

In the current research enterprise, behavior of novel bio-composites incorporating Aloe Vera fibers in biopolymer matrix (polylactic acid) has been experimentally examined in comparison to Sisal fi...

Saurabh Chaitanya

Papers

Processing of PLA/sisal fiber biocomposites using direct- and extrusion-injection molding

Recyclability analysis of PLA/Sisal fiber biocomposites

Sisal fiber-reinforced green composites: Effect of ecofriendly fiber treatment

Ecofriendly treatment of aloe vera fibers for PLA based green composites

Novel Aloe Vera fiber reinforced biodegradable composites—Development and characterization