Preparation of polyamides, polyurethanes, polysulfonamides, and polyesters by low temperature solution polycondensation

Solution polycondensation was used to prepare four classes of polymers. Polymers in each class were obtained with molecular weights high enough for formation into flexible, tough structures. In all instances the molecular weights were not as high as could be obtained from the same reactants by the interfacial polycondensation process. Many of the polyamides from aliphatic diamines were highly branched through diacylation of the amino groups. On the other hand, polysulfonamides were linear. Despite some limitations, as indicated above, the solution polycondensation process provides another route to forming condensation polymers and should be of special advantage in use with hydrolytically unstable intermediates, with water‐insoluble diamines and diols, and for forming uniform or block copolymers.