Compatibilizing effect of thermotropic liquid crystalline block-graft copolymer on liquid crystalline polycarbonate-polystyrene blend systems

✍ Scribed by Takanori Kobayashi; Moriyuki Sato; Noboru Takeno; Ken-Ichi Mukaida

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 679 KB
• Volume: 29
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(93)90256-f

✦ Synopsis

Thermotropic liquid crystalline (LC) block-graft copolymer (LCBG) composed of thermotropic LC polycarbonate (LCPC) in the backbone and polystyrene (PS) segment in the side chain (reported previously) was added to incompatible polymer blend systems of thermotropic LCPC and commercial PS as a compatibilizer. The compatibility, morphology and mechanical properties of the blends were evaluated by SEM, DSC and TMA measurements. No compatibility between the LCPC and the PS was found in the LCPC-PS blend systems (LCPC: PS = 2 : 8) but the SEM examination indicated that fibrils were formed in the systems to which the LCBG was added. This finding means that the compatibility between LCPC and PS is improved. Data for glass transition steps by DSC measurements support this view. The blend system containing LCBG (5 wt%) showed the best mechanical properties of all the systems. These results suggest that LCBG is a useful compatibilizer for the blend systems.