Synthesis and properties of hyperbranched aromatic Polyamides

Hyperbranched aromatic polyamides were prepared by one-step polycondensation of AB(x) type monomers. Despite the rigid aromatic structure, the hyperbranched polyamides showed good solubility and low viscosity in solution, which is typical for dendritic macromolecules. Direct polycondensation of AB(4) and AB(8) monomers gave polymers with a high degree of branching. Copolymerization of AB(2) and AB monomers resulted in the formation of copolymers with low branching density. The influence of the branching density on the properties of resulting polymers is discussed. It is interesting to note that the small amount of AB(2) branching point affected the properties of resulting copolymers dramatically. A novel successful thermal polycondensation of AB(2) type monomers to form hyperbranched polyamides is also described.