Processing and Compatibility of High-Density Polyethylene Blended with Particle and Liquid Biopolymer on Ultraviolet Exposure

Recently, there has been pronounced interest in polymer blends. Different types of polymer blends of two or more are mixed to create new type of polymer with different physical properties. Common type of high-density polyethylene (HDPE) is selected and has been mixed with biopolymer. Two different forms of biopolymers, that is, particle biopolymer and liquid biopolymer were mixed with HDPE, namely as HP and HL, respectively. The ratio of both biopolymer form is at 5, 10, 15, 20, 25 and 30% weight by weight percentage ratio (wt/wt) of HDPE. This is to study the processing condition and compatibility of HDPE with biopolymer in different form. HP and HL were mixed by using Brabender Plastograph machine complete with mixer and roller screw. The mixture of HP and HL were then injected into dumbbell shape of tensile specimen using injection moulding. Next, the specimen of tensile was exposed to the ultraviolet exposure for 3000 h in Ultraviolet Weatherometer chamber. The physical and mechanical properties of both forms of blended polymers were tested. The tensile strength of all ratios of HL shows higher mechanical strength as compared to HP. Meanwhile, Melt Flow Index (MFI) of HP shows higher value for all percentage ratios loading as compared to HL. This shows that the liquid form of biopolymer mixed with HDPE gives stronger intermolecular forces, which attracts polymer molecules towards each other. The liquid form of biopolymer was crosslinked and chemically joined together in places, by creating branched, or network structure. High crosslinked bonds in the polymer molecules hold the groups of polymer chains together to form stronger new types of polymeric material of HL.