Organosiloxane-Cross-Linked Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Network Structures

The use of two types of siloxane bridges as chemical cross-links in poly(phenylene oxide) (PPO) network structures was investigated. The PPO was initially functionalized through a bromination process and then cross-linked using two systems. The first used γ-aminopropyltriethoxysilane to produce relatively few siloxane bonds between cross-links, while the second utilized the same silane in combination with a higher molar mass, α, ω-functionally terminated poly(dimethyl siloxane) (PDMS) to provide longer chains between crosslinks. The resulting networks showed notable differences in tensile properties which depended on the type of crosslinks present. In addition, both elastomers showed good strength and elongation characteristics and reduced craze formation when compared to the PPO homopolymer.