Copolymerization Studies of Urethane Methacrylate and Ladder-Like Polysilsesquioxane Containing Side Chain Methacrylate Groups

Abstract

Urethane methacrylate (UMA) prepolymer was prepared by reacting 2 mole tolylene diisocyanate with 1 mole polyethylene glycol (molecular weight 400) followed by end-capping with 2 mole 2-hydroxyethyl methacrylate in N,N-dimethylformamide (DMF) solvent using stannous octoate as a catalyst. It took 72 h for complete reaction at ambient temperature as determined by monitoring the isocyanate peak at 2269 cm 11 . Ladder-like polysilsesquioxane (LPS) containing side chain methacrylate groups was prepared by stepwise coupling polymerization. Different weight fractions of UMA and LPS in DMF were copolymerized using 1% (w/w) dibenzoyl peroxide at 80 2 C for 24 h followed by post curing at 100 2 C for 4-5 h in a nitrogen atmosphere. The copolymers were characterized by Fourier transform infrared analysis, solid-state 13 C NMR spectroscopy, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis. No glass transition temperatures were observed for the copolymers by DSC. The WAXD patterns of copolymers showed a broad peak corresponding to the width of double chain of LPS, indicating the incorporation of LPS in copolymers. These copolymers were more resistant to acid medium. The temperature of 5% weight loss increased with increasing silsesquioxane content in both air and nitrogen atmospheres, and verified the incorporation of LPS in the copolymers.

Synthesis of ladder-like polyphenylsilsesquioxanes with fairly high regularity using 1,2-ethylenediamine as endo-template

“…Based on the supramolecular template polymerization technique proposed by Zhang et al, many regular LPSQs were designed and synthesized. Firstly, LPSQs containing side chain methacrylate groups [18] , lateral bromophenyl groups [19] , perfect phenelenediimino-bridged LPSQs [20] and 3-methyl-1,5-diphenylbenzene groups [21] were prepared using p-phenylene diamine as a template respectively. Later, soluble quadruple-chain LPSQs with high molecular weight [22] and a LPSQ with high regularity [23] were synthesized using m-phenylenediamine as a template.…”