Organo-soluble alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride

1

8-dimethyl-bicyclo[2.2.2]oct-7-ene-2

3

5

6-tetracarboxylic dianhydride (DMEA) and several multialkyl-substituted 4

4'-diaminodiphenylmethane compounds

including 3

3'-dimethyl-4

4'-diaminodiphenyl methane (DMDA)

3

3'

5

5'-tetra-methy]-4

4'-diaminodiphenyl methane (TMDA) and 3

3'

5

5'-tetraethyl-4

4'-diaminodiphenylmethane (TEDA). For comparison

the aromatic polyimides (ARPIs) were synthesized from the aromatic dianhydride

3

3'

4

4'-benzo-phenonetetracarboxylic dianhydride (BTDA) and the same diamines. The ALPIs exhibited better solubility and transparency

but worse thermal stabilities and mechanical properties than those of the ARPIs. And the ALPIs could be dissolved in common organic solvents

such as N-methyl-2-pyrrolidinone (NMP)

N

N-dimethylformamide (DMF)

N

N-dimethylacetamide (DMAc)

chloroform

tetrahydrofuran

m-cresol and so on. The ALPI films had an UV-Vis cut-off at 320 nm and a transmittance of higher than 80% in the visible region. In addition

the ALPIs showed thermal decomposition temperatures (Td) of about 450℃

which was nearly 100℃ lower than that of the ARPIs.