Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (12): 3765.doi: 10.7503/cjcu20210382

• Polymer Chemistry • Previous Articles     Next Articles

Synthesis and Optical Properties of Polycarbonates Copolymerized with Bisphenol Fluorene Moiety

DU Xinyao, WANG Wei, LIN Yu, WU Guozhang()   

  1. Shanghai Key laboratory of Advanced Polymeric Materials,School of Materials Science and Engineering,East China University of Science & Technology,Shanghai 200237,China
  • Received:2021-06-05 Online:2021-12-10 Published:2021-09-13
  • Contact: WU Guozhang E-mail:wgz@ecust.edu.cn

Abstract:

To reduce the birefringence of bisphenol A polycarbonate(BPA-PC), we intended to copolymerize bisphenol fluorene(BPEF) with BPA to prepare a copolycarbonate with intrinsic birefringence close to 0. We observed that catalysts with a large basic pKa value can reduce the difference in reactive activity between BPA and BPEF, thus increasing the molecular weight of copolycarbonates. When the polycondensation temperature is 265 ℃ and time is 40 min, the weight-average molecular weight of the synthesized PC with a feed molar ratio of BPEF/BPA of 40/60 reaches 39800. 1H NMR and 13C NMR analysis testify that all products are random copolymers. Increasing the content of BPEF leads to a high refractive index and a low birefringence value. When the BPEF molar fraction is 87%, the intrinsic birefringence is approximately 0.0028, which is very close to zero birefringence.

Key words: Polycarbonate, Copolymerization modification, Optical material, Molecular weight

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