| 摘要 |
1465825 Polyetherimides GENERAL ELECTRIC CO 2 May 1974 [22 June 1973] 19329/74 Heading C3R A polyetherimide having units is made by agitating a mixture of equimolar amounts of aromatic bis-(ether anhydride) and organic diisocyanate OCNR<SP>1</SP>NCO at #160‹ C. in the presence of a heterogeneous catalyst being a carbonate of an alkali metal (M); where R is a C 6-30 aromatic radical, and R<SP>1</SP> is a C 6-30 aromatic radical, or a cycloalkylene, C 2-20 alkylene, or C 2-8 -alkylene-terminated polydiorganosiloxane radical. The reaction may be performed in the melt at 160-350‹ C., or under reflux in the presence of a solvent at 160-300‹ C. There may be 0À01-1% wt. carbonate based on the mixture. Metal (M) may be Na, K, Rb, or Cs. The polymer may be recovered by filtering off the carbonate from a solution of the polymer, precipitating the polymer in water or methanol, and drying. The polymer may be blended in the melt with silica, glass fibres, C whiskers, or perlite. |
