No abstract

Poly­(lactic acid) (PLA) is well-known as a biocompatible and biodegradable polymer that can be obtained from natural sources. However, the brittleness of PLA is a significant drawback for its wide application. In this study, a poly­(lactic acid) (PLA)/polyurethane elastomer prepolymer (PUEP) dynamically vulcanized system was introduced and studied in detail. The torque, FTIR spectrum, and gel content demonstrated that PUEP was vulcanized and that the isocyanate (−NCO) group in PUEP was successfully reacted with the −OH groups at both sides of the PLA. The scanning electron microscopy (SEM) revealed that a relatively uniform phase morphology and good interfacial compatibilization were achieved in the dynamically vulcanized blends. The interfacial reaction and compatibilization between the component polymers resulted in the formation of supertoughened PLA/PUEP blended materials.

Polylactide (PLA)/halloysite nanotube (HNT) nanocomposites with different HNT contents were prepared by melt compounding. The morphology, crystallization behavior, as well as thermal and mechanical properties of the nanocomposites were studied. The results showed that HNT were well dispersed in PLA matrix. Thermogravimetric analysis data revealed that the thermal stability of PLA was decreased with the increasing of HNT content. Differential scanning calorimetry analysis indicated that the presence of HNT could promote cold crystallization and lead to different crystalline phase formation. The flexural and tensile modulus of PLA/HNT nanocomposites improved significantly with the incorporation of HNT. Compared with neat PLA foam, PLA/HNT nanocomposite foams showed much higher cell density and smaller cell size due to HNT serving as the heterogeneous nucleating agents. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

No abstract

Long-chain branching structure introduced by UV-induced reactive extrusion could widen its foaming processing window.