Effect of microcrystalline cellulose [MCC] fibres on the morphological and crystalline behaviour of high density polyethylene [HDPE]/polylactic acid [PLA] blends

Abstract

The present study describes the fabrication and characterization of eco-friendly composites based on high density polyethylene (HDPE), poly (lactic acid) (PLA) with microcrystalline cellulose (MCC) fibres via melt extrusion followed by injection moulding. The morphology of PLA in both HDPE/PLA blends and HDPE/MCC fibres composites was irregular and immiscible. The tensile strength at max load and % elongation at break of all polyblend composites were reduced to ~17%, ~15%, and ~84%, ~89% than pure HDPE matrix, respectively. The toughness of HDPE and its polyblend composites were decreased to ~92% and ~91%, respectively. As higher number indicates greater resistance, the hardness of HDPE was improved by ~7% and ~10% after adding PLA followed by MCC fibres. As revealed from DSC analysis, the crystallinity of composites was considerably influenced by the MCC fibres content due to the transcrystallization effect. The crystallinity of HDPE/PLA with MCC fibres polyblend composites was decreased by ~41% as compared to the HDPE matrix because of disorientation of fibres as seen in X-ray diffraction analysis. Eventually, the results revealed that the presence or absence of MCC fibre loading had significant effects on the mechanical, morphological, and thermal properties of HDPE/PLA blends.