Synthesis and Characterization of New Poly (amide-imide)s Based on 1,4-Bis(trimellitimido)-2,5-dichlorobenzene

摘要

A series of new aromatic poly (amide-imide)s were synthesized by the triphenyl phosphite-activated polycondensation of the diimide-diacid, 1,4-bis (trimellitmido)-2,5-dichlorobenzene (I), with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMR), pyridine, and calcium chloride. The poly (amideimide)s had inherent viscosities of 0.88-1.27 dL g~(-1).The diimide-diacid monomer (I) was prepared from 2,5-dichloro-p-phenylenediamine with trimellitic anhydride. All the resulting polymers were amorphous and were readily soluble in a veriety of organic solvents, including NMP and N,N-dimethylacetamide. Transparent, flexible, and tough films of these polymers could be cast from N,N-dimethylacetamide or NMP solutions. Cast films had tensile strengths ranging from 92 to 127 MPa, elongations at break from 4 to 24%, and initial moduli from 2.59 to 3.65 GPa. The glass transition temperatures of these polymers were in the range of 256 deg -317 deg C, and the 10% weight loss temperatures were above 430 deg C in nitrogen.