Landfills around the world are full of plastics and packaging materials, some of which may take decades or longer to completely break down. Plastics made from biodegradable polymers are much better for the environment compared to petroleum based/synthetic composites, because they break down substantially faster.
In recent years, the uses of natural fibres as the fillers for biodegradable/synthetic polymers have been increased. Cellulose is one of the prospective fillers to different polymers due to its reduced weight, relatively good stiffness and strength along with a low cost and ease of disposal.
In our work we prepared the cellulosic composites on the base of natural poly(lactic) acid (PLA) and synthetic low-density polyethylene (LDPE). The studied composite materials were manufactured with a twin-screw extruder. The extruded compound was compression moulded to test samples. The weight content of cellulose in PLA/cellulose and LDPE/cellulose composites was varied.
Effect of a small addition of cellulose on the rheological and tensile properties was studied. Tensile tests showed that the incorporation of cellulose into PLA or LDPE matrix lead to stiffer but slightly more brittle and weaker materials, since Young’s modulus increases and tensile strength and elongation at break decrease a little. Mechanical results are in agreement with rheological behaviour: the composites exhibit an improvement in the storage and loss moduli of composites compared with matrix polymers. The composite viscosity increases with cellulose content in the same manner as loss and storage moduli.
The processing and material properties of PLA/cellulose composites were compared with those of LDPE/cellulose composites.
Keywords: cellulose, poly(lactic) acid, biocomposites
Authors
Šumigin D.
Faculty of Chemical and Materials Technology, Tallinn University of Technology, Tallinn
Tarasova E.
Faculty of Chemical and Materials Technology, Tallinn University of Technology, Tallinn
Meier P.
Faculty of Chemical and Materials Technology, Tallinn University of Technology, Tallinn
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