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Synthesis and UV curing kinetics of rapidly UV‐curable hyperbranched polycarbosiloxanes
Author(s) -
Wang ShengJie,
Liu Xin,
Kong Jie,
Tian Wei,
Fan XiaoDong,
Xu Hai,
Lu JianRen
Publication year - 2010
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2861
Subject(s) - hydrosilylation , curing (chemistry) , monomer , materials science , silane , polymerization , uv curing , polymer chemistry , fourier transform infrared spectroscopy , kinetics , irradiation , photopolymer , photochemistry , chemical engineering , chemistry , composite material , organic chemistry , catalysis , polymer , physics , quantum mechanics , nuclear physics , engineering
Hyperbranched polycarbosiloxanes with peripheral photo‐crosslinkable groups were synthesized through controllable hydrosilylation reaction from A 2 ‐type and CB 3 ‐type monomers. The polymerization of the monomer pairs was monitored using Fourier transform infrared spectroscopy, from which it was found that vinyl silane and methacrylate groups reacted with hydride silane from the beginning of the reaction. The results thus suggest a step‐by‐step polymerization rather than a two‐step process for this system. The polycarbosiloxanes could be cured rapidly in either nitrogen or air atmosphere, this feature making them attractive for potential application as precursors of advanced ceramic devices with complex structures. The effects of light intensity, reaction temperature and atmosphere on the UV curing rate ( R p ) and conversion (α) of the photo‐crosslinkable groups were characterized carefully, and the curing kinetics was also investigated systematically. The results show that R p and α increased with an increase of light intensity or temperature, and that the inhibiting effect of oxygen in air could be suppressed by enhancing the irradiation intensity. Copyright © 2010 Society of Chemical Industry