Kinetics of UV curable alkyl 3-mercaptopropionate-vinyl silizane

Abstract

Photopolymerization of vinyl-containing liquid silizane preceramic monomers copolymerized with thiol monomers, based on a step-growth radical polymerization mechanism, is a novel, rapid, inexpensive and simple technique for producing preceramic structures from liquid precursors. The kinetics of alkyl 3-mercptopropionate-vinyl silizane under UV irradiation is investigated by using realtime Fourier transform infrared (FT-IR) and photo-differential scanning calorimetry (photo-DSC). The experimental results show preliminarily that: (1) about 80% conversion of vinyl group has been achieved in the presence of a low concentration photoinitiator under UV irradiation; (2) by increasing the functionalities of the thiol group, the peak rate of copolymerization increases and the final conversion of the vinyl group decreases; (3) the copolymerization is primarily a bimolecular radical termination process; (4) the copolymerization is first-order, i.e., its rate is proportional to the vinyl group concentration and independent of the concentration of thiol group.

UV‐activated hydrosilylation of (Me‐Cp)Pt(Me)3: Enhanced photocatalytic activity, polymerization kinetics, and photolithography

“…In order to understand the thermodynamics of photoactivated hydrosilylation between PDMS‐Vi and PMHS, the rate constant, activation energy, and reaction order are also estimated. The reaction rate equation is used where R is the polymerization rate, C 0 is the initial concentration of CC or SiH, C is the conversion of CC or SiH at time t , and k is the reaction rate constant.…”

Combined bead polymerization and Cinchona organocatalyst immobilization by thiol–ene addition

“…Trithiol 4 is a readily available commercial product, whereas dithiol 5 was easily obtained from esterification of 3-mercaptopropionic acid and propane-1,3-diol [ 14 ]. Trivinyl ether 6 , polyethylene glycol (PEG) dimethacrylate 7 , diacrylate 8 and diallyl ether 9 are all commercially available compounds.…”

“…Dithiol 5 was prepared as described in the literature [14], and this compound was kept refrigerated and protected from light in order to avoid deterioration on storage.…”

“…The Cinchona organocatalysts 2 and 3 were prepared from quinine ( 1 ) as described in the literature [ 15 ]. Dithiol 5 was prepared as described in the literature [ 14 ], and this compound was kept refrigerated and protected from light in order to avoid deterioration on storage.…”

Radical polyaddition of difunctional vinyloxirane with thiols for synthesis of linear and networked polysulfides

“…Trimethylolpropane tris(3‐mercaptobutanoate) (TMPTMB) and pentaerythritol tetrakis(3‐mercaptobutanoate) (PETMB) was provided from Showa Denko K. K. 1,3,5‐Tris(hydroxymethyl)benzene was synthesized by the reported procedure, and oxidized to afford 1,3,5‐triformylbenzene . Propane‐1,3‐diyl bis(3‐mercaptopropanoate) (PDBMP) was prepared from 3‐mercaptopropionic acid and 1,3‐propanediol by the reported procedure …”