Historically, most polymer materials which exhibit high thermal and/or mechanical properties contain aromatic monomer units. A typical example of this is bisphenol A polycarbonate. In recent years there has been an interest in a new series of copolyesters which contain 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). This aliphatic monomer imparts some very unique thermal and mechanical properties. This seminar will discuss the thermal properties of a new series of CBDO based co-polyesters. These polymers include CBDO, a series of bisphenols, and terephthaloyl chloride. The series of bisphenols discussed here include bisphenol A, AF, F, and HPF. These polymers display glass transition temperatures near 200C and decomposition temperatures from 390-420C (Argon) and from 385-410C (Air). Additionally a project involving the development of CBDO based copolyesters into transparent ballistic materials will be discussed.