Synthesis and characterization of new soluble polyimides derived from 2,2-bis[3,5-dimethyl-4-(4-aminophenoxy)phenyl]propane

Abstract

A diamine monomer containing isopropylidene and methyl substituted arylene ether, 2,2-bis[3,5-dimethyl-4-(4-aminophenoxy)phenyl]propane (TBAPP), was prepared in two steps. The monomer was reacted with six different aromatic tetracarboxylic dianhydrides in N.N-dimethylacetamide (DMAc) to obtain the corresponding new polyimides via the poly(amic acid) precursors and thermal or chemical imidization. The poly(amic acid)s obtained had inherent viscosities ranging from 1.38-2.10 dL . g 1 . All the poly-(amic acid)s could be cast from DMAc solutions and thermally converted into transparent, flexible, and tough polyimide films. The polyimide films had a tensile strength in the range from 52-95 MPa, an elongation at break within a range of 4-8%, and a tensile modulus in the range from 1.60-2.09 GPa. All polyimides were amorphous. The polyimides derived from diamine TBAPP had excellent solubility in various solvents except for those derived from rigid dianhydrides such as pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride. These polyimides showed glass transition temperatures between 249-293 C and decomposition temperature at 10% mass loss temperatures ranging from 460-485°C in nitrogen.