Transesterification Reactions in PC/PBT Blend in Presence of Nanoclay Particles and Their Effect on Blend Morphology

Recently، using nanoparticles in polymeric blend have been considered by many researchers a new epoch for generation of materials to meet different requirements in various industries such as car، sport، military، structure and electronic. The transesterification reaction in polyester blends during melt mixing plays an important role in the components compatibility، and the ultimate properties of the blend affected by this reaction. In this study the transesterification reaction in the blend of poly (butylene terephthalate) (PBT) /polycarbonate (PC) was studied at the presence of three commercial organic modified montmorillonite namely Cloisite 30B، Cloisite 20A and Cloisite 15A. The main difference among these nanoparticles is their surface chemical structures and initial gallery heights. Fourier transform infrared spectroscopy (FTIR) and small angel X-ray scattering (SAXS) analysis showed that tranesterification reaction was improved at the presence of Cloisite 20A and Cloisite 15A and an intercalation morphology was obtained. While in the samples containing Cloisite 30B a thermal degradation occurred and initial gallery of the nanoparticles was increased. Dynamical mechanical thermal analysis results revealed that by addition of nanoclay to polymer blend، the glass transition of polymers draw on to each other which means more compatibility has been obtained and transestrification reaction has been improved at presence of the nanoparticles. Scanning electron microscope (SEM) micrographs showed droplet-matrix morphology for PC/PBT: 70/30 ratio and co-continuous for PC/PBT: 50/50. By incorporation of nanoparticles the finer morphology was obtained in PC/PBT: 70/30 and co- continuous morphology changed to micro co-continuous in PC/PBT: 50/50.