KINETIC AND RHEOLOGICAL STUDIES OF 2 UNSATURATED POLYESTER RESINS CURED AT DIFFERENT TEMPERATURES

The effect of temperature on the curing kinetics of two unsaturated po lyester resins has been studied by Fourier transform infrared spectros copy. It has been found that at the beginning of the reaction, the kin etic mechanism was dominated by near-azeotropic copolymerization, whil e conversion of polyester vinylene groups became much more favourable than styrene later in the reaction. Both styrene and vinylene group co nversion at the end of isothermal cures were a function of the styrene content in the resin. The experimental results have been related to t he rheological changes during cure. Activation energies have been obta ined from both rheological and thermal techniques. Copyright (C) 1996 Elsevier Science Ltd