SOLUBLE POLYIMIDES WITH POLYALICYCLIC STRUCTURE .3. POLYIMIDES FROM (4ARH,8ACH)-DECAHYDRO-1T,4T-5C,8C-DIMETHANONAPHTHALENE-2T,3T,6C,7C-TETRACARBOXYLIC-2,3-6,7-DINHYDRIDE

New ladder-rich and soluble polyimides with a polyalicyclic structure were prepared from conventional aromatic diamines and a novel tetracarboxylic dianhydride with a tetraalicyclic structure, (4arH,-8acH)-decahydro-1t,4t:5c,8c-dimethanonaphthalene-2t,3t,6c,7c-tetracarboxylic 2,3:6,7-dianhydride(3). The dianhydride (3) was sythesized by a Diels-Alder (DA) reaction of 2,5-norbornadiene with cyclopentadiene, followed by the Pd(0)-catalyzed tetrakismethoxycarbonylation, an ester exchange reaction, and then the dehydration reaction. The structure of 3 was determined using NMR and single crystal X-ray analysis. The polyimides obtained from 3 were soluble in polar aprotic and protic solvents and had molecular weights in the range 1.1 x 10(4) to 5.8 x 10(4) as M(n)BAR. These polymers exhibited excellent thermal stability without significant weight loss up to 420-degrees-C. The T5's in nitrogen and in air were over 460 and 440-degrees-C, respectively. The T(g)'s were over 250-degrees-C except for the polyimide prepared from DDS as a diamine component. The polyimide films were found to be almost colorless. The films had a tensile modulus range of 1.71-2.30 GPa, a tensile strength range of 91-112 MPa, and an elongation range at break of 19-35%.