Curable silane-endcapped compositions having improved performance

摘要

Certain members of the class of N-silylalkyl-aspartic acid esters, when used to endcap polyurethane polymers, offer moisture curable, one-part sealant formulations having significantly improved physical property improvements over other members of the same class of organofunctional silanes. More specifically, polyurethane polymers terminated with either the dibutyl or diethyl maleate/primary aminoalkyl silane addition product offer sealants which substantially outperform comparative sealants obtained using polymers endcapped with other olefinic carboxylate ester (dimethyl maleate, dimethyl crotonate) or nitrile (acrylonitrile)/ primary aminoalkyl silane addition products. Additionally, sealant formulations incorporating the dibutyl or diethyl maleate/primary aminoalkyl silane terminated polymers demonstrate unexpected improvements in both elongation and tensile strength performance. The dibutyl maleate and dimethyl maleate based polymers give significant increase in tear resistance.