| 摘要 |
<p>1434212 Unsaturated polyimidazole and polyoxazole prepolymers and foams thereof TRW Inc 21 March 1973 [3 April 1972] 13677/73 Headings C3R C3P and C3C Curable prepolymers are prepared by reacting (A) an aromatic tetramine or dihydroxy or dithiol diamine with each amino group ortho to another or to a thiol or hydroxy group, (B) a dicarboxylic aromatic compound and (C) an end-cap component comprising an endo-compound wherein Y 1 to Y 7 are independently H, Ha, NO 2 , aryl, alkaryl or C 1-6 alkyl or alkoxy, or for Y 7 only, amino; X is CO, O, S, CH 2 or halogen, alkyl or aryl substituted CH 2 ; Z 1 is a direct link, arylene or C 1-4 alkylene; Z 2 is -COF, -COCl, -COBr, -COI, -COOH, -COOR or -NH 2 ; and R is aliphatic or aromatic. (C) may also include acrylic acid. The prepolymers may be cured at 230‹ to 370‹ C. for up to 4 hours at up to 700 atmospheres, optionally in conjunction with an olefinic monomer as cross linking agent. Various suitable reactants and olefinic monomers are specified. Additional cross-linking sites may be provided in the polymer chain by use of olefinic reactants, e.g. stilbene tetramine and pcarboxy cinnamic acid. In examples the prepolymer is prepared in solution in dimethylformamide and obtained as a powder by evaporation; the powder is cured at 350‹ C. to give a rigid foam in Examples II-IV.</p> |
