| 摘要 |
Polymeric articles are formed by compression, heating and moulding of a linear polymer resin with transition temp. 250 deg.C and room temp. modulus greater than 300,000 psi. The resin is compressed with a pressure of 10,000-100,000 psi. at 400 deg.C, and if desired the article may be sintered. In an example, a cylindrical mould with outer dia. of 1.25 inch is filled with 3g. powdered linear aromatic polyimide resin made by reacting 4,4'-oxidoaniline with pyromellitic dianhydride at 300 deg.C. for 10 min. Pressure is then brought to 40,000 lb. for 2 min. and the article removed from the mould. Article is easily cut or shaped and has density 1.415-1.418 g/cm3, and Shore hardness 92. |
