Biocomposites reinforced with natural fibers:thermal, morphological and mechanical characterization

Alessandra Luiza de Lemos,Nei Sebastião Domingues Junior,Pamela Galera Prestes Pires,Marcelo Lopes de Albuquerque,Vagner Roberto Botaro,Jane Maria Faulstich de Paiva

doi:10.1590/s1517-707620170002.0173

Alessandra Luiza de Lemos, Nei Sebastião Domingues Junior + Show 4 more

Open Access

https://doi.org/10.1590/s1517-707620170002.0173

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Abstract

ABSTRACT This study evaluates the thermal, morphological and mechanical behavior of polypropylene (PP) composite with different natural fibers. The fibers used were wood, sugarcane, bamboo, babassu, coconut and kenaf with and without coupling agent. The thermal, morphological and mechanical properties were evaluated, and a composite PP+GFPP (glass fiber) was used as reference. The interaction at the interface fiber-polymer matrix was studied by scanning electron microscopy (SEM) at the fractured surface of the composites, as expected the presence of maleic anhydride (MA) as coupling agent increasedthe interaction at the interface. The influence of natural fiber in the degree of crystallinity of the composites was evaluated by DSC analysis. The samples of PP+GFPP and PP+(PP-MA)+WF (wood flour) showed better temperature stability. PP+GF also presented superior flexural modulus. The thermal dynamic mechanical behavior was evaluated by DMA, a decrease in storage modulus with increasing temperature was observed, the PP+GF and the composite containing maleic anhydride and sugarcane fiber showed higher modulus. The natural fiber biocomposites studied, consistently presented lower flexural modulus and tensile strength than the reference composite, with and without the use of coupling agent. As expected the use of natural fibers lowered the density compared to the reference material.

Highlights

The growing interest in products with lower environmental impact makes the use of natural fibers as reinforcing agents a viable technical alternative
This study aims to evaluate the mechanical, morphological and thermal behavior of composite thermoplastic polymer matrix of homopolymer polypropylene, reinforced with six different types of natural fibers, with and without the use of polypropylene grafted with maleic an
The composite PP+GFPP, showed the best results in tensile strength and flexural modulus, Figure 1-a, compared to the polypropylene composites with natural fibers regardless of the presence or not of the coupling agent

Summary

Introduction

The growing interest in products with lower environmental impact makes the use of natural fibers as reinforcing agents a viable technical alternative. The use of bio-sourced materials is increasing in an attempt to reduce the amount of thermoplastic polymers from non-renewable sources. The biggest challenges that involve composite materials are good interface interaction between the natural fiber and the polymer matrix. When properly compounded natural fibers make good candidates to replace currently used glass fiber as reinforcing agent, in addition to that, they are abundant and renewable and can be generally considered as biodegradable and non-toxic. This study aims to evaluate the mechanical, morphological and thermal behavior of composite thermoplastic polymer matrix of homopolymer polypropylene, reinforced with six different types of natural fibers, with and without the use of polypropylene grafted with maleic an-

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