Maleated polyethylene as a compatibilizing agent in cannabis indica stem’s flour-reinforced composite materials

Abstract

Ethylene propylene diene terpolymer (EPDM) composites reinforced with wood flour of White Russian indica cannabis (ICF), a variety of marijuana obtained from government-licensed crops, were prepared. Wide particle size distribution range (136–1580 µm) of ICF was used. The wood flour was superficially treated with sodium hydroxide, and subsequently washed and dried. Composites with 30 and 60 parts of ICF by weight per hundred of rubber (phr) were prepared. Maleated polyethylene (MAPE) was used as a compatibilizer/coupling agent. The rubber compounds were mixed on a laboratory two-roll mill and cured composite sheets were obtained using compression molding technique. The effects of ICF and MAPE on the mechanical and physical properties of composites were analyzed. The addition of MAPE had positive effects on tensile strength, abrasion resistance, tear strength and compression set. The compatibilizing agent also had a slight effect on the hardness. The Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results confirmed that MAPE improved the interfacial adhesion between the ICF particle and EPDM matrix. ICF and MAPE slightly affected the crystallinity, characterized using X-ray diffraction microscopy, and curing behavior of the composites. Lightweight (ρ = 0.92 g/cm3) composites were obtained with load levels up to 60 phr of ICF.