Novel unsaturated polyesters based on MEXDIOL (a mixed glycol), isophthalic acid, maleic anhydride and succinic acid/suberic acid/sebacic acid have been synthesized by a ＇3-step＇ polyesterification process. The structures of these novel unsaturated polyesters have been established on the basis of the ＇process of synthesis＇ and IR. Further, these novel unsaturated polyesters have been characterized for various properties. The data indicate that the increase in the chain length of dibasic acid results in increase in gel time, elongation, nitroglycerine (NG) absorption and thermal conductivity and decrease in exotherm peak temperature, tensile strength, bond strength with CMDB propellants, hardness and heat resistance. The trends in properties have been explained in terms of assigned structures.