Studies on phase separation of polyesterimide-modified epoxy resins. I. Syntheses and properties of organo-soluble polyesterimides

摘要

A series of polyesterimides based on aromatic bis(trimellitate) dianhydride in main chain were prepared by polycondensation of t-butyl-p-phenylenebis(trimellitate) dianhydride (BPBDA) and phenylene bis (trimellitate) dianhydride (PBDA) with benzidine and its derivates. The results show that the incorporation of noncoplanar structure led by introducing alkyl substituents on dianhydride and benzidine can improve the solubility of polyesterimides in organic solvents. It also displays that the introducing substituents lead to a decrease in glass transition temperature and influence the beta relaxation of PEsI. By comparing the chemical structure and the dynamical mechanic date,, we suggest that the beta relaxation correspond to the motion involving the imide ring and phenylene groups of the diamine. [References: 13]