Improvement in Tensile Strength and Water Repellency of Paper after Treatment with Methyltrimethoxysilane Oligomer Using Titanium Butoxide as a Catalyst

The improvement in the tensile strength and water repellency of paper after treatment with a 2-propanol solution of a methyltrimethoxysilane (MTMS) oligomer was studied using filter paper. Titanium butoxide introduced in the solution as a catalyst effectively reacted with the MTMS oligomer, and a Si–O–Ti bond was generated inside the paper. The tensile strength of the paper was remarkably improved by this treatment of impregnation and polymerization of the MTMS oligomer. It was speculated that the reaction proceeded by consuming water that existed among the cellulose fibers by hydrogen bonding, because there was little difference in the tensile strength between the paper treated in air and the paper treated in a dry box. The methoxy groups in the MTMS oligomer demonstrated their good ability of making a three-dimensional network, and at the same time, the methyl groups in the oligomer showed their excellent water repellency. As a result, the treated paper had a good tensile strength even under wet conditions.