Nanocomposites based on polycarbonate/poly (butylene terephthalate) blends effects of distribution and type of nanoclay on morphological behavior

Abstract

Polycarbonate/poly (butylene terephthalate) (PC/PBT) is an example of an immiscible/(partially miscible) binary polymer blend with a wide range of applications. In some applications, the low stiffness limits the end uses of this blend and can be improved by the incorporation of nanoparticles. Nanocomposites based on PC/PBT and three types of commercial layered silicate were prepared via melt processing by using an internal mixer. The three types of organoclay were Cloisite 15A, Cloisite 20A, and Cloisite 30B. The main aim of the work focused on the morphology behavior and the determination of the location of the organoclays in the polymeric phases. The wetting coefficient based on Young's equation was evaluated in order to predict the distribution of organoclays in the polymeric phases by considering the temperature effect. The results revealed that the three types of organoclay were located in the PBT phase, while the results from transmission electron microscopy, scanning electron microscopy, and dynamic mechanical thermal analysis showed a contradiction for Cloisite 30B that was attributable mainly to thermal degradation of this type of nanoparticle during melt processing. Morphological studies showed that intercalated morphology for nanocomposites containing Cloisite 20A and Cloisite 15A led to significant enhancement of the transesterification reaction, while de-intercalation occurred for samples including Cloisite 30B. J. VINYL ADDIT. TECHNOL., 19:203-212, 2013. © 2013 Society of Plastics Engineers