Study of the microgelation of unsaturated polyester resins by dynamic light scattering

Abstract

Abstract A series of unsaturated polyesters were synthesized with various chemical structures and molecular weights. The effects of molecular weight and degree of unsaturation on the curing reaction of these polyesters with styrene were studied by means of dynamic light scattering and differential scanning calorimetry. Two modes of size distribution of the microgel particles formed during the curing reaction were found from dynamic light scattering data. The small particles consist of primary unsaturated polyester molecules. The large ones consists of microgel particles formed by linking adjacent polyester molecules. The size and structure of the microgel particles depend strongly on the polymer chain length and the number of vinyl groups in each unsaturated polyester chain. The experimental results of this study revealed that microgel formation has a great effect on the curing reaction of unsaturated polyester resins.