酚醛改性苯并噁嗪树脂耐烧蚀材料的研究

Study on the ablative materials of phenolic resin-modified benzoxazine resins

对不同组成苯并口恶嗪/酚醛共混树脂体系进行了研究,内容包括共混树脂的反应动力学参数计算、共固化机理、热分解动力学以及耐烧蚀性能等。结果表明:酚醛与苯并口恶嗪树脂共混后可以改变苯并口恶嗪的固化机理,酚醛树脂的加入使口恶嗪分子由热开环变为活泼氢开环,在较低温度下就可以反应,降低了固化反应温度。同时共混树脂可以使固化过程收缩率和小分子挥发物比传统的酚醛树脂低,可以减少烧蚀试样的表面裂纹,致密的碳化层具有一定附着强度,提高了共混树脂烧蚀性能。该共混体系可以作为宇航领域中1种性能优良的耐烧蚀树脂体系。

The different proportion of benzoxazine/phenolic blend resins was investigated. Kinetics of reaction, co - reaction mechanisms and ablative property of the mixed resins were studied. Experimental results indicated that the mixture of phenolic and benzoxazine might change the cure mechanism of benzoxazine resin, i.e. the thermo- ring- opening of benzoxazine was changed to ring - opening by active hydrogen addition reaction at lower temperature and reduce the cure temperature. At the same time, the blend resins could make the cure shrinkage and small molecule volatilization in the cure process lower than that of common phenolic resin, reduce surface crack of ablative sample and the densified coat had cohesional strength so its ablative property was increased and the blend resins could be used as a kind of excellent ablative resin system for aerospace field.