Studies on Mechanical, Thermal Properties, Characterization and UV-Accelerated Weathering of HIPS-PLA Blends using Glycerol as Compatibilizer  (English, Paperback, B. Dinesh, S. Soundararajan)

HIPS (High Impact Polystyrene) was blended with PLA (poly lactic acid) in three formulations as 80:20, 65:35 and 50:50% (wt%) using a twin screw extruder and by using glycerol (4%) as compatibilizer. Test specimens were prepared by using an injection moulding machine and the mechanical, thermal and electrical properties were determined. The tensile strength first decreases and then increases with increasing percentage of PLA, but lower than that of both HIPS and PLA. MFI and hardness increases, while impact strength, HDT and VSP decrease with increase in percentage of PLA. The density and water absorption increases with increases in PLA composition, whereas mould shrinkage decreases with increases in PLA content. The arc resistance increases with increases in PLA content. The main objective of this project is to develop petroleum based and bio based blend with need of reducing the usage of petroleum based plastic materials and increasing the usage of bio based plastic materials for the sustained use of the manmade plastics materials, and decrease the disposal problem. Even though HIPS is petroleum based, it is photo-biodegradable. PLA is starch based and it is biodegradable. Hence HIPS-PLA blend is photo/bio-degradable. The accelerated UV weathering test shows that the blends are easily degradable. DSC shows 50:50% of HIPS-PLA is found to be compatible, which is also confirmed by SEM. But other formulations were not compatible.