Thesis (M.Eng.)--Chulalongkorn University, 2008

In this research, the effect of silane coupling agents on properties of Poly (vinyl chloride)/Bagasse composites which were produced from poly (vinyl chloride) and untreated or treated bagasse were evaluated. The surface of bagasse was modified by treating the fiber with γ-aminopropyltriethoxysilane (amino), N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (diamino) or glycidoxypropyltrimethoxysilane (epoxy). Particularly, this research studied the effects of various types and concentrations of silane coupling agents on mechanical, thermal, and water absorption properties of composites. Bagasse at 60 phr with fiber sizes of 45-106 µm and 106-180 µm were used. PVC dry blend and bagasse were mixed in a two-roll mill followed by compression molding. The composites with treated bagasse showed the increase in the tensile and flexural properties. It showed that tensile and flexural strengths of these composites increased between 24-27% and 14-17%, respectively, compared to composites with untreated fiber. In addition, these composites with treated bagasse absorbed less amount of water than composites with untreated bagasse. However, types and concentrations of silane coupling agents did not show significant effect on impact strength and thermal properties of PVC/bagasse composites. Among three types of silane coupling agent used, the composites with bagasse treated with amino silane coupling agent at 2% by weight of bagasse showed the best results in tensile and flexural properties and they also showed the lowest amount of water absorption.