Extensão de cadeia do poli (butileno-adipato-tereftalato) utilizando aditivo polifuncional epoxídico.

Abstract

Biodegradable polymers are an environmentally friendly alternative, as they minimize environmental problems and reduce accumulation of waste plastics. This work is concerned with degradation and chain extension of the biodegradable polymer poly(butylene-adipate-terephthalate) (PBAT) with an epoxidic chain extender additive (Joncryl). The PBAT without and with different concentrations chain extender was processed in a laboratory internal mixer Haake Rheomix 3000 with "roller" type rotors. The variation of molar mass was estimated from temperature and torque data versus time provided by the equipment during melt processing. The effect of the additive depends mostly on processing temperature, less on additive concentration. Incorporation of additive during melt processing not only offset the slight degradation of the resin during processing in the internal mixer, but resulted in net increase of molecular weight. The molecular weight more than doubled at 230°C with 2% additive. For high additive concentrations were observed sometimes long times of induction with catastrophic fall of torque, attributable to imperfect mixing of the components