The resin solution of NA capped "PMR" type polyamideimide (PAI) was prepared frpm bicyclo [2. 2. 1] hept-5-ene-2

3-dicariboxylic acid ethyl ester

1

2

4-trimellitic acid-2-(or-1-) ethyl ester and 4

4'-diaminodiphenyl methane in ethanol. This resin solution is specially suitable for the preparation off composites. The flexural strenght of the glass fabrics reinforced plastic was 6000-7000 Kg/cm2 (RT) and 4000-4400 Kg/ cm2 (260-300℃)

respectively. The result of isothermal ageing for 800 hours indicated that this composite can be used at 260℃. The mechanism of the formation of poly-amide-imide was discussed by using appropriated model compounds.