Processing and characterization of poly(lactic acid) blended with polycarbonate and chain extender

Abstract

Currently, use of poly(lactic acid) (PLA) is limited for commercial applications because it has a low heat resistance. In this research, an increase of over 40°C heat distortion temperature (HDT) of PLA alloy was obtained by blending PLA with polycarbonate (PC) and a chain extender (CE). Molecular weight, thermal, mechanical and morphological properties of PLA and PC blend with different CE contents were investigated. Gel permeation chromatography (GPC) results showed that some PLA-PC copolymers were produced and the compatibility of the PLA phase and in the PC phase was improved via the chain extension reaction. In addition, the reaction induced by CE also affected the crystallization behaviors of PLA, as observed from differential scanning calorimetry (DSC) results and the enthalpy of melting of PLA decreased with increasing CE content. The combined effects of the CE increasing molecular weight, improving compatibility and limiting the crystallization behavior of PLA/PC alloy greatly improved the HDT.

Improved Impact Properties in Poly(lactic acid) (PLA) Blends Containing Cellulose Acetate (CA) Prepared by Reactive Extrusion

“…Another interesting strategy for improving PLA mechanical resistance at high temperatures is blending with polymers that have a glass transition temperature higher than that of PLA [28]. In particular, blending with poly(carbonate) of bisphenol A, which has a glass transition temperature of about 150 °C, has been investigated by several researchers [10,29,30,31,32]. The extrusion of poly(lactic acid)/polycarbonate (PLA/PC) blends in the presence of a catalyst consisting of triacetine and tetrabutylammonium tetra-phenylborate (TBATPB) was successful in achieving this result [31,33].…”

Effect of glass fiber reinforcement on the thermal, mechanical, and flame retardancy behavior of poly(lactic acid)/polycarbonate blend

“…The mechanical strength of this blend is relatively less than the mechanical strength of the components when no additives such as compatibilizer or fiber. For this reason, there are many studies on the compatibilizer of the PLA/PC blend in the literature . Lee et al determined the effects of three different compatibilizers to mechanical, morphological, and rheological properties of PLA/PC blend.…”

“…Srithep et al studied adding epoxy‐based chain extender as a compatibilizer in the PLA/PC blend. It was reported that the molecular weight and miscibility of the blends increased with the addition of chain extenders …”

“…For this reason, there are many studies on the compatibilizer of the PLA/PC blend in the literature. [21][22][23][24] Lee et al determined the effects of three different compatibilizers to mechanical, morphological, and rheological properties of PLA/PC blend. Poly (styrene-g-acrylonitrile)-maleic anhydride (SAN-g-MAH), poly(ethylene-co-octene)-rubber-maleic anhydride, and poly(ethylene)-co-glycidyl methacrylate) were selected as compatibilizer in this study.…”

“…It was reported that the molecular weight and miscibility of the blends increased with the addition of chain extenders. [22] Another used technique for improving the mechanical properties of the PLA/PC blend is fiber reinforcement. The fibers added to the polymer matrix help reduce the effect by keeping the pulse or distributing it to the matrix and sometimes holding the matrix together.…”