Effect of Different Blend Ratios and Compatibilizer on Tensile Properties of Recycled Poly(propylene)/Recycled High Density Polyethylene Blends

Summary Polymer blending is an efficient way for tailoring products with required set of properties and is often more cost effective when recycling. In this study, the effect of different blend ratios on tensile properties, morphology and crystallinity of recycled poly(propylene) (rPP) and recycled high density polyethylene (rHDPE) were studied. Polyethylene maleic anhydride (PEMA) as compatibilizer was used to improve the properties of rPP/rHDPE blends. The blends were prepared using a counter rotating twin screw extruder. The tensile strength and elongation at break of uncompatibilized blends decreased with increasing rHDPE content, whereas the modulus of elasticity increased. The crystallinity of rPP decreased with increases of the rHDPE content, but the crystallinity of rHDPE increased in uncompatibilized blends. It was found that tensile strength and modulus of elasticity of compatibilized rPP/rHDPE blends higher than uncompatibilized blends. The SEM micrograpgh of tensile fractured surface of compatibilized rPP/rHDPE showed better interfacial adhesion and interaction between rPP and rHDPE. It was also found that the crystallinity of compatibilized rPP/rHDPE blends enhanced with the presence of PEMA.