Suitable Methoxysilane and Its Oligomer for Tensile Strength Improvement in Treated Paper Using Titanium Butoxide as Reaction Accelerator

Abstract

For investigating the suitable methoxysilane and its oligomer for improving the tensile strength of treated paper after its hydrolysis and poly-condensation, three methoxysilanes (tetramethoxysilane (TMOS) , methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane) and two oligomers (TMOS and MTMS oligomers) were impregnated into the base paper using titanium butoxide as the reaction accelerator. Among the three methoxysilanes, the highest impregnated weight (7.2 g/m 2 ) was obtained when a TMOS solution was used. The highest tensile strength was obtained when an MTMS solution was treated (4.3 kN/m, 130 % increase compared to the base paper). On the other hand, for the two oligomers, the highest weight was 50 g/m 2 and the highest strength was 6.8 kN/m (200 % increase) when an MTMS oligomer solution was treated. These differences in the improvement of the weight and strength between the monomer solutions and the oligomer ones were due to the monomer's high volatility. The reason why the MTMS oligomer produced the highest strength treated paper is attributed to its molecular characteristics. Because the MTMS has one unhydrolyzable group (methyl group) and three hydrolyzable groups (methoxy groups), it is assumed that the balance between the flexibility resulting from the methyl group and the hardness from the methoxy groups produced the moderate tension in the generated polymer. The MTMS oligomer has the same balance as the MTMS. Among the MTMS oligomers having different degrees (n = 3.1, 4.4, 6.3, 8.7, 12.4 and 26.1 ) , there was only a slight difference in strength. The most suitable methoxysilane compound for improvement of the tensile strength was the MTMS oligomer.