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美国国家空間飞行管理局的研究中心,最近試制成功两种适用于宇宙航行的耐辐射高聚物。其中之一是聚[乙撐-2,6-萘二羧酸酯],与聚对苯二甲酸二乙酯相似,仅以2,6-萘二羧酸取代对苯二甲酸而已。經过这样改变以后,这种聚酯高分子材料的耐輻射稳定性就大有提高。另一种高聚物是聚[咪唑并吡咯酮](polyimidazopyrrolones)。这种高聚物兼有咪唑和吡咯酮結构。是从聚咪唑和聚苯并咪唑发展出来的。这两种高聚物分子中只能有三个稠环,而缀咪唑并吡咯酮則至少可以有四个稠环,而且在梯形結构达到完善的情况下,还可以更多一些。这类高聚物的結构式可以描述如下:
NASA’s research center at the United States recently successfully prototyped two radiation-tolerant polymers suitable for astronautics. One of them is poly [ethylene-2,6-naphthalene dicarboxylate], similar to polyethylene terephthalate, except that 2,6-naphthalene dicarboxylic acid replaces terephthalic acid. After this change, the polyester polymer materials greatly improved the stability of the radiation. Another polymer is polyimidazopyrrolones. This polymer has both imidazole and pyrrolone structures. From polyimidazole and polybenzimidazole developed. There are only three condensed rings in the two polymer molecules, and at least four fused rings in the imidazopyrrolone, and more if the ladder structure is perfect. The structural formula of such polymers can be described as follows: