Abstract
A series of polyimides having cyclopentane structure in the main chain were prepared by reacting cis, cis, cis, cis-1,2,3,4-cyclopentane tetracarboxylic dianhydride and aromatic diamines comprising multiaromatic rings linked with various flexible linkages (ether, isopropylidene, hexafluoroisopropylidene, sulfonyl, sulfide) by the conventional two-step method. The imidization of poly (amic acid)s to polyimides were followed by infrared (IR) spectroscopy and resultant polyimides had inherent viscosities in the range of 0.42~0.90 dL/g. These polymers were observed to be practically amorphous as shown by the X-ray diffraction studies and were generally soluble in a wide range of organic solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, o-chlorophenol, m-cresol, pyridine and 1,4-dioxane. The glass transition temperatures of the polymers occurred over the temperature range of 178~258$^{\circ}C$ in their differential scanning calorimetry (DSC) thermograms. In addition, thermal stabilities of these polyimides were also evaluated by thermogravimetric analysis (TGA), which showed that their 10% weight loss temperatures and char yields were in the range of 380~50$0^{\circ}C$ and 5~42%, respectively, under the air and nitrogen atmospheres.