The Effects of Blending Ratio of Poly(lactic acid)/POSS Cored Star Poly(ε-caprolactone) Biopolymers

Abstract

A8-type eight-arm star-shaped poly(ε-caprolactone) (PCL) polymers with polyhedral oligomericsilsesquioxane (POSS) (SP) core having different molecular weight with different chain lengths (n=10, 20,30, and 50 repeating units) were synthesized via arm-first approach by a combination of ringopening polymerization (ROP) and “click” chemistry reactions. The obtained polymers were then meltblended with neat poly(lactic acid) (PLA) to improve some of the properties like the toughness of PLA. Theseblends were prepared depending on the blend ratio (95/5 and 80/20 wt%) via utilizing laboratory-scaletwin-screw mini extruder to examine morphological, thermal, and mechanical properties of PLA/SPcomposite as a function of SP and blending ratio. Also, the PLA/SP composites containing a blend ratio of90/10 wt%, which were prepared in the previous study, was used to compare with other composite havingdifferent blend ratio. The incorporation of SP polymers improved some of the mechanical properties of PLA.It was verified that SP20 (n=20) is the most proper SP-type for enhancing the mechanical behavior of PLAat a blending ratio of 90/10. Also, 1,4-phenylene diisocyanate (PDI), which was used as a commercialcompatibilizer, was incorporated to blends at a fixed amount (%1). It is concluded that the incorporation ofSP polymers into PLA matrix decreased the tensile modulus with increasing blending ratio and increased theelongation at break values in the presence of PDI.