Synthesis and Properties of Sequentially Ordered Copolyesters and Regioregularly Ring Substituted Aromatic Homopolyesters

Copolyesters having well-defined sequential order and aromatic polyesters having regioregularly positioned substituents were successfully synthesized via multistep routes. Their properties such as thermal transitions, thermotropic properties, crystallization tendency etc. were compared with those of random sequence copolyesters and randomly substituted counterparts. The polymers of regular micro-chemical structures were found to have much higher melting transition temperatures and greater degree of crystallinity than those having irregular structures. It also was learned that positional isomerism of the substituents leads to different crystal structure.