Biodegradable aliphatic polyester

초록

Biodegradable polymers have been used for numerous niche applications such as surgical implants, sutures, and controlled release drugs. However owing to the formidable recent efforts to develop low cost biodegradable polymers to reduce the solid waste produced by many artificially synthesized polymers, many plastics used for single-use receptacles fishing tools and packagings of fresh meat and fish have become targets to be replaced with biodegradable polymers. Poly(L-lactide) (PLLA) is one of the most economically competitive biodegradable polymers produced from renewable resources. There have been several attempts to improve the end-use properties of PLLA by way of PLLA/clay nanocomposites. In this study, Cloisite25A®(C25A) was modified with (glycidoxypropyl)trimethoxy si lane (GPS) to introduce epoxy groups onto C25A. The twice functionalized organoclay (TFC) thus prepared was compounded with PLLA. The epoxy functional groups of the TFC may react with the end groups of PLLA to improve mechanical properties of the PLLA/TFC composites. ot only tensile modulus and strength but also elongation at break of the PLLA/TFC composites increased considerably as a result of the incorporation of TFC.TEM image of PLLA/TFC demonstrated the presence of individual layers as well as a few packets of silicate consisting of 2-3 layers, and a higher degree of exfoliation of the silicate layers was obtained for the PLLA/TFC composite than for the PLLA/C25A composite. The higher degree of exfoliation and the improved tensile properties of the PLLAITFC composites are believed to be associated with the epoxy functional groups of the TFC which promoted an interaction between the clay and the polymer via the chemical reaction. This is despite the fact that the XRD pattern of the neat TFC was almost identical to that of the neat C25A.