Mei Qilin, Wang Honghua, Chen Xiaocheng, Wang Ying, Huang Zhixiong
School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
Polymers (Basel). 2020 Mar 19;12(3):684. doi: 10.3390/polym12030684.
With the rapid development of thermal protection systems for the aerospace industry and power electronics, polyarylacetylene (PAA) resin plays an important role because of its good mechanical properties, high glass transition temperature (T), low water absorption, high char yield (Y), and the fact that there is no byproduct released in the curing process. In order to further improve the thermal property of PAA based FRP for the thermal protection field, the introduction of a zirconium element into arylacetylene is promising. In this paper, zirconium modified arylacetylene (ZAA) resin was prepared by two-step synthesis. The FTIR analysis characterized its molecular structure and confirmed the products. The viscosity of ZAA was about 6.5 Pa·s when the temperature was above 120 °C. The DSC analysis showed that the ZAA had a low curing temperature, and its apparent activation energy was 103.86 kJ/mol in the Kissinger method and 106.46 kJ/mol in the Ozawa method. The dielectric constant at 1 MHz of poly(zirconium modified arylacetylene) (PZAA) was 3.4. The TG analysis showed that the temperatures of a weight loss of 5% (T) and char yield (Y) at 800 °C of PZAA were 407.5 °C and 61.4%, respectively. The XRD results showed the presence of SiO and ZrO in the PZAA residue after ablation. The XRF results showed that the contents of SiO and ZrO in PZAA residual after ablation were, respectively, 15.3% and 12.4%. The SEM showed that the surface of PZAA after ablation had been covered with a dense and rigid ceramic phase composed of ZrO and SiO. Therefore, the introduction of Zr into arylacetylene greatly improved the densification of the surface after ablation, and improved the heat resistant property.
随着航空航天工业和电力电子领域热防护系统的快速发展，聚芳基乙炔（PAA）树脂因其良好的机械性能、高玻璃化转变温度（T）、低吸水性、高残炭率（Y）以及固化过程中无副产物释放等优点而发挥着重要作用。为了进一步提高用于热防护领域的PAA基纤维增强塑料（FRP）的热性能，将锆元素引入芳基乙炔中具有很大的潜力。本文采用两步合成法制备了锆改性芳基乙炔（ZAA）树脂。傅里叶变换红外光谱（FTIR）分析对其分子结构进行了表征并确认了产物。当温度高于120℃时，ZAA的粘度约为6.5Pa·s。差示扫描量热法（DSC）分析表明，ZAA的固化温度较低，基辛格法测得其表观活化能为103.86kJ/mol，小泽法测得为106.46kJ/mol。聚（锆改性芳基乙炔）（PZAA）在1MHz时的介电常数为3.4。热重分析（TG）表明，PZAA在800℃时失重5%（T）的温度和残炭率（Y）分别为407.5℃和61.4%。X射线衍射（XRD）结果表明，烧蚀后的PZAA残渣中存在SiO和ZrO。X射线荧光光谱（XRF）结果表明，烧蚀后PZAA残渣中SiO和ZrO的含量分别为15.3%和12.4%。扫描电子显微镜（SEM）显示，烧蚀后PZAA的表面覆盖有由ZrO和SiO组成的致密刚性陶瓷相。因此，将Zr引入芳基乙炔中极大地提高了烧蚀后表面的致密化程度，并改善了耐热性能。
