The morphology and deformation behavior of poly(butylene terephthalate) blends

Abstract

Impact-modified blends of BPA polycarbonate (BPAPC) and poly(butylene terephthalate) (PBT) are being used to an increasing extent in engineering applications requiring superior low temperature toughness (e.g., automotive bumpers). In order to optimize the performance of these materials in such demanding situations, it is essential to develop a thorough understanding of the factors affecting their microstructure and deformation behavior. To be successful in this endeavor, an interdisciplinary effort involving detailed microscopic characterization, sophisticated mechanical testing, and careful analytical studies is required. Although some work of this type has appeared in the literature (1,2) together with more fundamental research on BPAPC/PBT miscibility (3-6), major questions with respect to phase segregation, distribution of blend components, and morphological changes which occur during deformation remain.In response to these issues, a more complete investigation of the microstructure and deformation characteristics of several PBT blends containing various combinations of polycarbonate and impact modifier was recently carried out in our laboratory.