摘要
采用不同的甲醛 (F) /苯酚 (P)比和复合碱性催化剂合成了邻对位羟甲基比例 (o/p)不同的酚醛树脂。利用该酚醛树脂中邻对位交联程度变化可以优化炭化过程中苯醌式结构中间体稠环化历程 ,从而通过适当调整酚醛树脂受烧蚀而发生炭化时的交联密度 ,使炭化过程稳定 ,易于石墨化 ,提高了抗烧蚀性能。F/P比在 1. 6～ 1. 8时 ,纯酚醛树脂的炭化率与玻璃纤维 /酚醛树脂复合材料的质量烧蚀率变化较小 ,烧蚀形貌显著改善 。
Phenolic resins which had various orth/para hydroxy methyl ratios were synthesized by use of complex alkali catalysts and under various ratios of formaldehyde/phenol The fused ring transition mechanism of carbonization of phenolic resin could be optimized by altering the orth/para crosslink degree, the course of carbonization could go slowly and steadily, and the char yielded show a high tendency towards graphitization under high temperature, and so ablative ability could be improved When the formaldehyde/phenol ratios were in 1 6～1 8,the phenolic resins′ ablation morphological appearances were ameliorate, and their char yields and ablation rates of the composite were relatively ideal
出处
《材料工程》
EI
CAS
CSCD
北大核心
2002年第7期36-39,共4页
Journal of Materials Engineering
关键词
热防护材料
酚醛树脂
结构
烧蚀
heat protection material
phenolic resin
ablate
composite
