| Résumé : |
A novel hydroxy silane coupling agent (HO-silane) was synthesized via Michael addition reaction between 2-hydroxyethyl acrylate and 3-mercaptopropyl-trimethoxysilane, which was then used to synthesize the silane-terminated polyurethane (SPU). The silane-terminated polyurethanes, which showed low viscosity due to the end-capping by HO-silane, could be chain-extended by butanediol to enhance the performance of SPU in non-solvent condition. The effects of chain extender, 1,4-butanediol, and NCO/OH molar ratio (R value) on the properties of silane-terminated polyurethane were investigated. The results show that the hydroxy silane coupling agent and the silane-terminated polyurethane that can be moisture-cured at ambient temperature were successfully synthesized. It is found that by introducing the 1,4-butanediol segment into SPU main chain, the viscosity of SPU was increased, but the tack free time of SPU was shortened, and the hardness and tensile strength of the moisture-cured SPU film were enhanced. As the R value increased, the tack free time of the silane-terminated polyurethane was prolonged, and the hardness and the tensile strength of the moisture-cured film were increased, but the elongation at break was decreased. When the amount of 1,4-butanediol was 10 wt% and the R value was 1.3, respectively, silane-terminated polyurethane with viscosity of 51,000 mPa·s (80% solid content) can be obtained. The tensile strength of the moisture-cured film was 1.1 MPa, and the elongation at break was 713.4%, which shows great potential for sealant and coating applications. |
Aller sur edunet
Accueil
Synthesis of hydroxy silane coupling agent and the silane-terminated polyurethane chain-extended by butanediol in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 19, N° 5 (09/2022)
