• blends;
  • copolymers;
  • compatibilization;
  • foams;
  • surfaces and interfaces

A small amount of low-decomposition temperature poly(methyl methacrylate), (low-Td PMMA), can be used as a compatibilizer for high-decomposition temperature PMMA (high-Td PMMA) and polycarbonate (PC) blend systems. When low-Td PMMA is thermally decomposed in the PMMA/PC blend, the PMMA-g-PC copolymer is formed. This copolymer decreases the interfacial tension between PMMA and PC, decreases the domain size of PC and increases the interfacial area. Blends of high-Td PMMA/PC with different amounts of low-Td PMMA undergo a batch physical foaming with CO2. With increasing amounts of low-Td PMMA, which is equivalent to increasing the PMMA-g-PC copolymer, the number density of bubbles increases due to the increase of the interfacial area of disperse domains. However, the interfacial tension is decreased and the heterogeneity of PMMA/PC blend is decreased with increasing amounts of the copolymer. The number of bubbles per unit interfacial area and that per unit number of domains are decreased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39228.