Synthesis of poly(vinyl ether) optical plastics by cationic copolymerization of tricyclodecane vinyl ether with functionalized vinyl ethers

Abstract

AbstractCationic copolymerizations of tricyclodecane vinyl ether (8‐vinyloxytricyclo[5.2.1.02,6]decane, TCDVE, with vinyl ethers containing a functional group such as urethane linkage, acrylate group, and methacrylate group, as a comonomer were carried out to obtain poly(vinyl ether) plastics for optical use. With the hydrogen chloride/zinc chloride initiating system, the homopolymerization rates of these monomers were markedly different from each other, but the reaction rates of each monomer in the copolymerizations were almost identical. All the obtained copolymers displayed unimodal and narrow molecular weights distributions (MWDs). These facts show that the copolymers are most likely to have randomness with respect to monomer sequences. The copolymers obtained with BF3OEt2 as an initiator, in contrast, had relatively high molecular weights (Mn = 21,900 − 37,200) and broad MWDs (Mw/Mn = 4.10 − 6.31), which are rather suitable for molding of plastic materials. For the copolymer with the pendant urethane linkages, the existence of hydrogen bonding via urethane linkages among the polymer chains was detected. For the copolymers with the pendant acrylate or methacrylate group, exothermic peaks due to cross‐linking reaction were observed at around 150°C on the heating scan during the DSC measurement and therefore, they formed cross‐linked polymers during the molding process above this temperature. Both the hydrogen bonds and the cross‐linkages provide the copolymers with good processability and hardness. The optical properties of these copolymers were excellent and similar to those of poly(TCDVE). The transparency (86–91%) and refractive index (1.53–1.54) of these molded samples were similar to those of conventional optical plastics such as poly(methyl methacrylate) (PMMA) and polycarbonate (PC), whereas their specific gravity (1.08–1.12) and water absorption (0.08–0.16%) were significantly lower than those of PMMA and PC. The thermal decomposition temperatures of all the copolymers were 298–369°C, indicating their good thermal stability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012