Effect of chemical structure on physical properties of isomeric polyesters

It has been shown that changes in chemical structure of aromatic polyesters have a pronounced effect on the melting points and crystallinity of the polymers. Changes which remove the carboxyl group from the ring result in marked lowering of the melting point and toughness of the polymers. Changes which separate aromatic nuclei lower melting point but not as markedly as the above change. Changes which put an odd number of atoms in the polymer chain markedly lower the melting point. Changes which interfere with the possibility of co‐planarity of the components very markedly affect the crystallinity, and to a lesser extent the sticking point of polymers.