Thiourethane‐based thiol‐ene high T_g networks: Preparation, thermal, mechanical, and physical properties

Abstract

Thiourethane-based thiol-ene (TUTE) films were prepared from diisocyanates, tetrafunctional thiols and trienes. The incorporation of thiourethane linkages into the thiol-ene networks results in TUTE films with high glass transition temperatures. Increases of T g were achieved by aging at room temperature and annealing the UV cured films at 85 8C. The aged/annealed film with thiol prepared from isophorone diisocyanate and cured with a 10,080-mJ/cm 2 radiant exposure had the highest DMA-based glass transition temperature (108 8C) and a tan d peak with a full width at half maximum (FWHM) of 22 8C, indicating a very uniform matrix structure. All of the initially prepared TUTE films exhibited good physical and mechanical properties based on pencil hardness, pendulum hardness, impact, and bending tests. V V C 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5103-5111, 2007

Advanced functionalization of polyhydroxyalkanoate via the UV-initiated thiol-ene click reaction

“…This reaction between azides and alkynes offers high yields and involves functionalities that can be introduced relatively easily in a variety of molecules. In addition to the CuAAc, the thiol-ene reaction is also important in the realm of click chemistry (Carioscia et al 2007;Hoyle andBowman 2010, Hoyle et al 2004;Li et al 2007). Campos et al reported the synthesis of various macromolecules via the UV-initiated thiol-ene click reaction, which proceeded quantitatively, with a high degree of specificity in a matter of minutes (Campos et al 2008;Killops et al 2008).…”

The preparation and physical properties of polysulfide-based elastomers through one-pot thiol-ene click reaction

“…The use of oligomeric thiols has the distinct advantage of low shrinkage and a reduction in stress during the photopolymerization process [20] or lower glass transition temperatures and more uniform networks [21]. In other work, thiocarbamate oligomers are synthesized to prepare photocured/thermal cured films with high glass transition temperature, excellent hardness and impact values [22]. The present investigation also extends thiol-ene click reaction to a long chain liquid polysulfide (PSF) oligomer containing terminal thiol groups.…”

Preparation of Novel Hydrolyzing Urethane Modified Thiol-Ene Networks

“…Polyisocyanates can be end-capped by reacting with ene containing alcohols, resulting in urethane bridged oligomers that may be efficiently polymerized with thiols. Each monomer can be specifically chosen to modify the coating for the desired mechanical properties such as glass transition temperature (T g ) and film hardness [23]. Using these techniques, the benefits of thiol-ene click reactions and mechanical toughness of urethane bonds can be combined into one continuous film.…”

“…Urethane bonds form quickly through the reaction of isocyanate (NCO) and alcohol (OH) functional groups to produce relatively inexpensive and durable coatings, having strong mechanical properties, good abrasion resistance, and thermal stability [21]. Recent efforts of the Hoyle research group [22][23][24] demonstrate that the modification of thiol-ene networks with urethane segments may result in the improvement of selected polymer network properties specifically imparting impact adsorption, elastic properties and fracture toughness [22,24]. Polyisocyanates can be end-capped by reacting with ene containing alcohols, resulting in urethane bridged oligomers that may be efficiently polymerized with thiols.…”