A study of the compatibilizing liquid crystalline copolymer POB/ PET (60/40) with Polycarbonate through reactive blending

• Main Authors: Shi-I Yen, 顏士益
• Other Authors: Kung-Hwa Wei
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/79496925901793876738

碩士 === 國立交通大學 === 材料科學(工程)研究所 === 82 === Blends of bisophenol-A Polycarbonate (PC) and copolyesters such as liquid crystalline Poly (p-oxybenzoate-co-ethylene terephthalate) (60/40, P64) were prepared by melt-mixing at high temperatures. The thermal property of the blends was studied with Differe- ntial Scanning Calorimetry (DSC). It found that the glass trans- ition temperature (Tg) of the blends decreased with increasing mixing time and the concentration of P64 (LCP) in the blends. The kinetics of the transesterification reaction between the PC and the P64 was studied with Fourier Transformed Infrared sp- ectroscopy (FT- IR) and Nuclear Magnetic Resonance spectroscopy (NMR) during the mixing.The results indicated that the miscibil- ity between the PC and the P64 increased with the P64 concentra- tion and the blending temperature and time. The rheology of the copolyester (P64), PC, and their blends was measured with a controlled stress (CSL-100) rheometer, In t- he whole shear range, the viscosity of the host PC blends was r- educed by the presence of the P64. The miscibility of the blends was found to be influenced by the ester exchange reaction through Scanning Electron Microscopy (SEM).SEM observation indicated that in the beginning the copol- yester (P64) existed in the form of droplet in the PC matrices. The size of the droplets decreased with the blending time, and the number of the droplets seem to decrease with the blend- ing temperature, indicating the ester exchange reaction took p- lace. Polarizing optical microscopy showed the liquid crystalline structure existed in the blends system,and the birefrigence phe- nomenon decreased when the blending time was prolonged.