Morphology and properties of EVA/empty fruit bunch composites

Abstract

Composites based on ethylene vinyl acetate (EVA) copolymers with 18% and 28% VA contents and empty fruit bunch (EFB) fibre were reported in this study. The EVA-EFB composites were prepared by melt mixing using a Brabender plastograph mixer. Scanning electron microscopy (SEM) results show an improved extent of interfacial adhesion between the polymer and the fibre, with an increase amount of VA in the copolymers. Differential scanning calorimetry (DSC) results reveal that the melting and crystallization enthalpies decreased significantly with increasing VA content, while the presence of EFB fibre had very little influence on the melting and crystallization behaviour of both EVA18 and EVA28. Thermogravimetric analysis (TGA) results show that EVA18 is more thermally stable than EVA28 due to the higher amount of VA in EVA28, and the decomposition of EFB fibre seems to be retarded when it is incorporated into the EVA copolymers. Dynamic mechanical analysis (DMA) results show that both the storage modulus and loss modulus decrease significantly with an increase in VA content, and that these two properties observably increased with the incorporation of the fibre. The glass transition temperature also increased observably with increasing fibre loading, and decreased with an increase in the VA content. The stress and strain at break showed a similar decrease with increasing fibre content for both EVA18 and EVA28, while Young's modulus increased much more significantly with increasing fibre content for EVA28. Generally, it seems as if the improvement in interaction between EVA28 and EFB was not significant enough to overcome the inherent weak properties of EVA28.

Effect of surfactant on EG dispersion in EVA and thermal and mechanical properties of the system

“…There is a shift in the T g to higher temperatures with an increase in EG content. This is indicative of reduced chain mobility in the amorphous regions of the polymer due to the interaction between EVA18 and EG, and is in line with previous observations . The T g of the SDS‐EG containing composites shows similar increases with increasing filler content (Table ).…”

“…The nucleation effect seems to be more prevalent when the particles are smaller, as in the case of the SDS modified EG. Our previous study on the same EVA mixed with empty fruit bunch fiber showed a smaller (10%) increase in EVA crystallinity, when mixed with the same amount of fiber, than the EVA mixed with SDS modified EG. The melting and crystallization temperatures as well as the melting and crystallization enthalpies of these samples are summarized in Table .…”

“…The EVA copolymer with 18 wt % VA content used in this article is the same as the one used in our previous work on EVA filled with empty fruit bunch fiber . As far as we could establish there is no other published work where the thermal and mechanical properties of EVA blended with EG and with surfactant modified EG prepared through melt‐mixing were compared.…”

Properties and characterization of ([Mengkuang leaf fiber]‐filled ethylene vinyl acetate)/(natural rubber) blend: Effects of blending sequences and mengkuang leaf fiber loading

“…The second possible cause is the irregular shape of MLF, which leads to poor fiber dispersion and insufficient adhesion between the fiber and the polymer matrix. These may result in weak interaction and bonding between the fiber and the matrix, resulting in the deterioration of the tensile strength . In addition, at higher loading, fibers normally experience the pullout phenomenon and detach from the matrix, as could be observed from SEM studies.…”

“…However, rapid developments of natural fiber thermoplastic composites are limited, because of the strong hydrophilic nature of the natural fibers, which causes poor adhesion between the matrix and the fiber . The concept of using bio‐based materials reflects the increasing number of publications on the utilization of natural fibers such as jute , kenaf , sisal , pineapple leaf , bamboo , empty fruit bunch , and wood . Among several existing natural fibers, Mengkuang leaf fiber (MLF) has been selected as a reinforcement in the matrix.…”