COPOLYMER AND CROSS-LINKING EFFECTS IN POLYESTERS AS REVEALED BY HIGH-RESOLUTION SOLID-STATE C-13 NMR AND DSC

The unsaturated polyesters prepared from maleic anhydride and 2,2'di(4 -hydroxypro-poxyphenyl)propane and crosslinked at different temperatur es with various amounts of styrene were studied by means of high resol ution C-13 NMR in the solid state (CP/DD/MAS) and DSC. Experimental an d theoretical values of the proton rotating frame spin-lattice relaxat ion time, T-1p(H), and the glass transition temperature, T-g, were det ermined. The copolymer and crosslinking effects described by the NMR r elaxation times were found to be in agreement with those reflected by T-g. A correlation was found between the extent of these effects due t o curing conditions and the mechanical properties of the styrene-cross linked networks. (C) 1998 Elsevier Science Ltd. All rights reserved.