Hyperbranched Aromatic - Fat Polyamide Synthesis And Characterization,

In this paper, two new AB₂ monomers, 4-(3,5-diaminobenzamido)butanoic acid and 11-(3,5-diaminobenzamido)undecanoic acid, were prepared. Through the method of ploycondensation in solution and in melted state respectively, two Novel Hyperbranched aromatic-aliphatic polyamides were prepared from the two monomers. End-capping reactions of the terminal amino groups were accomplished with four kinds of acid chlorides respectively,then eight hyperbranched polyamides with different terminals were obtained. Their structures were confirmed by 1R, ¹H NMR, ¹3C NMR.The Degree of Branching (DB) of the resulting polymer1 and polymer2 were calculated by the ¹H NMR, and the DB of polymers obtained from condensation in solution, were higher than the DB of polymers from melted state. The inherent viscosity, solubility and glass transition temperatures of the resulting polymers were measured. Their inherent viscosity was low, ranging from 0.05dL/g to 0.22dL/g, and their solubility was high, which were accorded with the character of hyperbranched polymer. Their glass transition temperatures were affected by the flexibility and polarity of end-groups. The greater polarity of end-groups were, the higher the glass transition temperatures were.But the greater the flexibility of polymers and end-groups were, the lower the glass transition temperatures were.The heat-resistant stabilization of the resulting polymers were fine.The studies on the synthesis and performance of these hyperbranched aromatic-aliphatic polyamide will conduce to the development of the theory and application of hyperbranched polymer.