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首页> 外文期刊>ACS applied materials & interfaces >Space Survivable Polyimides with Excellent Optical Transparency and Self-Healing Properties Derived from Hyperbranched Polysiloxane
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Space Survivable Polyimides with Excellent Optical Transparency and Self-Healing Properties Derived from Hyperbranched Polysiloxane

机译：超支化聚硅氧烷衍生的具有优异光学透明性和自修复性能的可空间生存的聚酰亚胺

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A novel space survivable polyimide with a variety of desirable properties such as excellent thermal stability, high optical transparency, good mechanical strength, satisfactory break elongation, and outstanding atomic oxygen (AO) erosion resistance has been prepared by first synthesizing hyperbranched polysiloxane (HBPSi) and second incorporating HBPSi into polyimide (PI) chains via copolyconden-sation reactions. The ~(29)Si nuclear magnetic resonance (~(29)Si NMR) spectrum of HBPSi indicated that HBPSi possessed hyperbranched topology. The ground-based simulated AO exposure experiments demonstrated the mass loss of HBPSi polyimides decreased with increasing HBPSi addition and AO fluence, and it reached as low as 7.7% that of pristine polyimide when HBPSi addition was 29.7 wt % after 22 h AO exposure. Surface morphologies confirmed that pristine polyimide was significantly roughened after AO exposure while HBPSi polyimide had even less rough surface topography. During exposure of HBPSi polyimide to AO, the organic polyimide of the surface was first degraded and a silica protective layer eventually formed, which enabled the surface to be "self-healing". It is this passivation layer that prevents the underlying polymer from additional erosion. The whole preparation process of HBPSi polyimide is moderate, low-cost, environmentally friendly, and suitable for industrialized mass production, which contributes this novel'[ material to a "drop-in" replacement for the widely used Kapton on spacecrafts functioning in space environment,
机译：通过首先合成超支化聚硅氧烷（HBPSi）和苯并噻吩，制备了一种新型的具有多种所需性能的空间可生存的聚酰亚胺，如优异的热稳定性，高的光学透明性，良好的机械强度，令人满意的断裂伸长率以及出色的抗原子氧（AO）侵蚀性能。第二步是通过共缩聚反应将HBPSi掺入聚酰亚胺（PI）链中。 HBPSi的〜（29）Si核磁共振谱（〜（29）Si NMR）表明HBPSi具有超支化拓扑。地面模拟AO暴露实验表明，随着HBPSi添加量和AO通量的增加，HBPSi聚酰亚胺的质量损失降低，当AO暴露22 h后HBPSi添加量为29.7 wt％时，其原始损失仅为原始聚酰亚胺的7.7％。表面形貌证实，原始的聚酰亚胺在暴露于AO后显着变粗糙，而HBPSi聚酰亚胺的粗糙表面形貌甚至更低。在HBPSi聚酰亚胺暴露于AO的过程中，首先降解了表面的有机聚酰亚胺，并最终形成了二氧化硅保护层，这使表面能够“自我修复”。正是该钝化层防止了下面的聚合物受到额外的侵蚀。 HBPSi聚酰亚胺的整个制备过程温和，低成本，环境友好，适合工业化批量生产，这为将这种新颖的材料“替代”了广泛使用的在太空环境中运行的航天器上的Kapton ，

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