Synthesis and characterization of new highly organosoluble poly(ether imide)s derived from 1,1-bis[4-(4-dicarboxyphenoxy)phenyl]-4-tert-butylcyclohexane dianhydride

A new bulky pendent bis(ether anhydride), 1,1-bis[4-(4-dicarboxyphenoxy)phenyl]-4-tert-butylcyclohexane dianhydride (3), was prepared in three steps starting from nitro-displacement of 1,1-bis(4-hydroxyphenyl)-4-tert-butylcyclohexane with 4-nitrophthalonitrile to form bis(ether dinitrile) (1), followed by alkaline hydrolysis of the bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). A series of new poly(ether imide)s were prepared from such bis(ether anhydride) (3) with various diamines by a conventional two-stage synthesis including the polyaddition and subsequent chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities in the range of 0.50–0.79 dl g−1. The GPC measurement revealed that the polymers exhibited number-average and weight-average molecular weight up to 64,000 and 142,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility and were readily soluble in various solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran and even in chloroform. These polymers had glass transition temperatures in the range of 227–266°C. Most of the polymers could be dissolved in chloroform of as high as 30 wt% concentration. Thermogravimetric analysis showed that all polymers were stable up to 450°C, with 10% weight loss recorded in the range of 470–515°C in nitrogen. These transparent, tough and flexible polymer films could be obtained by solution cast from the DMAc solution. These polymer films had tensile strength in the range of 79–98 MPa and tensile modulus in the range of 1.8–2.0 GPa.