Thermodynamic evolution of unsaturated polyester-styrene-hyperbranched polymers

The free energy of mixing during cure has been modeled for different blends of linear unsaturated polyester, styrene and allyl ether functional hyperb ranched polymers. The molecular weight of the blend components has been imp lemented as measured by gel permeation chromatography (GPC) into the Flory- Huggins equation. This approach enables the distinction to be made between the contributions of enthalpy and entropy of mixing, the latter being autom atically followed during curing by the development of average molecular wei ghts. The model allows gaining an idea of the factors acting as driving for ces for chemically induced phase separation in these blends.