Polyimide foams having enhanced compression fatigue life and softness for use in the manufacture of seat cushions and methods for the production of such foams and precursors therefor. These foams are produced from polyimides prepared by reaction of an organic tetracarboxylic acid or derivative thereof, preferably an ester with (a) 1 to 50 mol percent of a diester of (i) a primary amino-substituted aromatic carboxylic acid, and (ii) a polymethylene glycol, and (b) at least one aromatic or heterocyclic primary diamine. Foams can be produced having (a) a fatigue life as determined by ASTM test procedure D 3574-81 using foam specimens from three to five inches in thickness (7.6 to 12.7 cm) of at least 15,000 cycles, or (b) an indentation force deflection as determined by ASTM test procedure D3574-81 on foam specimens of one-inch thickness of less than 40 pounds of force (178N) at 25% deflection and less than 180 pounds of force (801N) at 65% deflection, or both of (a) and (b).
聚
酰亚胺泡沫塑料具有更长的压缩疲劳寿命和更柔软的特性,可用于制造座垫和生产这种泡沫塑料及其前体的方法。这些泡沫是由有机四
羧酸或其衍
生物(最好是
酯类)与(a)1-50 摩尔%的(i)伯
氨基取代芳香族
羧酸和(ii)聚亚甲基二醇的二酯,以及(b)至少一种芳香族或杂环族伯二胺反应制备的聚
酰亚胺生产的。可生产出具有以下特性的泡沫:(a) 根据 ASTM 试验程序 D 3574-81 确定的疲劳寿命,使用厚度为 3 至 5 英寸(7.6 至 12.7 厘米)的泡沫试样,经 ASTM 试验程序 D3574-81 测定,疲劳寿命至少为 15,000 周;或 (b) 经 ASTM 试验程序 D3574-81 测定,一英寸厚的泡沫试样在挠度为 25% 时的压痕力挠度小于 40 磅力(178N),在挠度为 65% 时的压痕力挠度小于 180 磅力(801N);或 (a) 和 (b) 两项均达到。