Polymer, Vol.42, No.13, 5599-5606, 2001
Reactions of some anhydride-containing copolymers with gamma-aminopropyltriethoxysilane
This work describes the synthesis and macromolecular reactions of maleic anhydride (MA)-methyl methacrylate (MMA) binary and MA-trans-stilbene (Stb)-n-butyl methacrylate (BMA) ternary reactive copolymers with gamma -aminopropyltriethoxysilane (APTS) as a polyfunctional crosslinker. Copolymers with given compositions of MA-MMA (77.7 mol%) and MA (22.7 mol%)-Stb-BMA (54.2 mol%) are synthesised by radical binary and ternary copolymerisations with benzoyl peroxide as an initiator in toluene at 70 degreesC and initial monomer ratios 1:4 and I:1:1, respectively. It is shown that the network structure is formed in MA-MMA/APTS and MA-Stb-BMA/APTS in methyl ethyl ketone (MEK) solutions by intermolecular reactions between the anhydride unit and the amine group, as well as between the ethoxysilyl fragment and the free carboxyl group formed after the amidisation of the anhydride unit. Swelling parameters, such as the beginning time of xerogel-formation, initial rate of swelling and equilibrium swelling, are determined for the copolymer/APTS/MEK system with various polymer/crosslinker ratios. Formation of a hyperbranched network structure through the fragmentation of side-chain reactive groups in the studied systems is confirmed by FTIR, TGA and DSC methods.