Diphenolic 9,9-Diarylfluorene Trimers and Derivatives Possessing Flexible Alkylene Chain Spacers: Synthesis of the Monomers, Their Polymerization, and Properties of the Resulting Polymers

Abstract

9,9-Diarylfluorene-based monomers capable of controlling the thermal properties of the corresponding polymers were synthesized. The monomers possess flexible alkylene chains linking 9,9-diarylfluorene units with diphenol, dialcohol, and diamine terminal units. All of these terminal units were synthesized from a common trimeric tert-alcohol-functionalized intermediate. Polycarbonates consisting of the 9,9-diarylfluorene trimer structure in the main chains were synthesized by interfacial polycondensation with triphosgene. The polymerizability of the diphenolic trimer was sufficiently high to afford a polycarbonate with a high molecular weight (Mw 334 000). The thermal properties (Tg and Td) of the polymers were easily controlled by adjusting the feed ratio of the 9,9-diarylfluorene trimer to 9,9-bis(4-hydroxyphenyl)fluorene. The resulting highly transparent polymers showed high refractive indices and low birefringence values originating from the cardo structure.