Biopolyethylene/macaiba shell (Acrocomia intumescens) composites compatibilized with PE-g-MA and PE-g-AA: Influence of macaiba oil on processing

The present investigation aimed to produce ecological composites of biopolyethylene (BioPE) with macaiba shell (MS), using polyethylene-graft-maleic anhydride (PE-g-MA) and polyethylene-graft-acrylic acid (PE-g-AA) as compatibilizers, as well as macaiba almond oil as a plasticizing agent. The composites were processed in a co-rotational twin-screw extruder and injection molded. The addition of 30% by weight of MS in the BioPE matrix caused a reduction in impact strength and elongation at break, but improved stiffness and heat deflection temperature. The PE-g-MA and PE-g-AA compatibilizers improved the impact strength of the composites, suggesting increased interactions between the phases. There was an increase in the composites degree of crystallinity, indicating that the MS acted as a nucleating agent. The macaiba oil addition to the composites increased the impact strength, indicating a plasticizing effect. However, the elastic modulus, tensile strength, and degree of crystallinity tended to decrease. In general, the use of PE-g-MA compatibilizer was more effective to improve the composites mechanical properties. The reuse of MS is feasible for the production of sustainable composites.