Chapter 6
Downloaded by UNIV OF CALIFORNIA SAN DIEGO on August 26, 2015 | http://pubs.acs.org Publication Date: March 3, 2003 | doi: 10.1021/bk-2003-0847.ch006
Allyl Ethers in the Thiol-ene Reaction Ingemar Carlsson, Adrian Harden, Stefan Lundmark, Ana Manea, Nicola Rehnberg*, and Lennart Svensson Perstorp Specialty Chemicals AB, S-284 80 Perstorp, Sweden
Characteristics of polyol mercaptoalkanoates, polyol allyl ethers and coatings produced thereof are reported. The viscosities of examined thiols are in the range of 110-410 mPas (23 °C) and the density of functional groups 4-8 mmol/g. The corresponding data for the studied polyol allyl ethers are 3-240 mPas (23 °C) and 7.5-13.3 mmol/g, respectively. Formulations of these components were made and photocured as thin films (100 μm wet, glass plates) using benzophenone as initiator. The coatings were characterized with respect to methyl ethyl ketone resistance (generally > 200 single rubs), pendulum hardness (typical value 140 Ks), contact angle (44-70°), glass transition temperature (-39-2 °C), and thermogravimetric infra red analysis. The latter indicated the thiol-ene coatings to be of good thermal stability (typically 4% weight loss at 300 °C).
© 2003 American Chemical Society
In Photoinitiated Polymerization; Belfield, K., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.
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Introduction In the presence of free-radical initiators, thiols (RSH) add to double bonds by a free-radical mechanism and the orientation is anti-Markovnikov. The reaction has been known since the beginning of the last century (i) and basic mechanistic studies were undertaken in the 1930:ies. The photo-induced polymerization has been reviewed excellently (2). Thiol-ene polymerizations proceed by a step growth addition mechanism that is propagated by a chaintransfer process which is in contrast to the chain mechanism of photopolymerization of e.g., acrylate or epoxy monomers, Figure 1.
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