Synthesis and liquid-crystalline properties of thermotropic homopolycarbonates

✍ Scribed by Christel De Backer; Marcel Van Beylen; Raoul Ottenburgs; Celest Samyn

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 1002 KB
• Volume: 196
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1995.021960512

✦ Synopsis

Six series of polycarbonates with flexible spacers have been prepared by melt condensation of aromatic diols such as 4,4'-bis[(2-hydroxyethyl)oxy]biphenyl, 4,4'-bis[(6-hydroxyhexyl)oxy]biphenyl, 1,5-bis[(2-hydroxyethyl)oxy]naphthalene, 1,5-bis[(6-hydroxyhexyl)oxy]naphthalene, 2,6bis[2-hydroxyethyl)oxy]naphthalene, 2,6-bis[(6-hydroxyhexyl)oxy]naphthalene, 4,4'-bis[(6-hydroxyhexyl)oxy]stilbene, 3,3'-dimethyl-4,4'-bis[(2-hydroxyethyl)oxy]stilbene, 3,3'-dimethyl-4,4'bis[(6-hydroxyhexyl)oxy]stilbene, 4,4'-bis [(2-hydroxyethyl)oxy]-a-methylstilbene and 4,4'-bis[(6- hydroxyhexy1)oxyl-a-methylstilbene b, with several alkylene diphenyl dicarbonates. Polycarbonates with biphenyl and stilbene mesogenic groups show liquid-crystalline behavior with the formation of a nematic phase over a temperature range of 46°C and 21 "C, respectively. Amorphous polycarbonates were obtained when 1 ,haphthalene or a-methylstilbene groups are incorporated. Polymers with 2,6-naphthalene and 3,3'-dimethylstilbene groups show mesophase formation up to a certain spacer length, a transition range of 15 "C and 28 "C, respectively, being observed.