Improvement of compatibility, thermal stability and mechanical properties of poly (phenylene oxide) (PPO) and liquid crystalline polymer (LCPA950) blends with epoxy containing acrylate rubber (ACM) as a compatibilizer

Abstract

This paper proposes a new approach for improving the compatibility of liquid crystalline polymers with engineering thermoplastics. To improve compatibility and mechanical performance of poly (phenylene oxide) (PPO)/liquid crystalline polymer (LCP) A950 blends, a third component compatibilizer is incorporated into the processing step. In this work, epoxy containing acrylate rubber (ACM) is used for the compatibilization of PPO/LCPA950 blends through the chemical reaction of epoxy functional groups of the acrylate rubber with terminated carboxylic acids or hydroxyl end groups of the two phases. The compatibilization effect on the properties of PPO/LCPA950 blends is investigated by adjusting the amount of acrylate rubber. Fourier transform infrared (FTIR) spectroscopy and melt-rheological analysis were used to study the compatibilization mechanism of acrylate rubber, and the results demonstrate that acrylate rubber is capable of reacting with PPO/LCPA950 to form a chemical bonding interface. The electron microscopic images revealed a well-compatibilized microstructure of PPO/LCPA950 blends in presence of acrylate rubber with submicron-sized liquid crystalline polymer domains in the continuous poly (phenylene oxide) matrix phase, which could not be detected for immiscible PPO/LCPA950 blend. The dynamic mechanical analysis shows that PPO/LCPA950 blend with acrylate rubber exhibit greater elastic storage moduli. It was observed that blends of PPO/LCPA950 compatible with acrylate rubber showed significant increases in tensile strength as well as notched impact strength. These blends can be used in automotive industry.