含磷腰果酚基羟基型固化剂的合成及其阻燃环氧树脂的研究

Effects of phosphorus-containing cardanol-based hydroxyl type curing agents on properties of flame retardant epoxy resins

随着环保意识的增强,开发高性能生物基环氧树脂以减少对石油基双酚A二缩水甘油醚(DGEBA)和4, 4’-二氨基二苯甲烷(DDM)的依赖越来越受到重视。基于腰果酚、苯酚、甲醛溶液和氯代磷酸二苯酯等原料合成了三种官能团数目可调控的腰果酚基羟基型固化剂(P1C1F-0.6DCP、P2C1F-0.6DCP和P3C1F-0.6DCP)并对其阻燃环氧树脂开展了相应的研究。垂直燃烧和极限氧指数(LOI)结果表明,DGEBA/P1C1F-0.6DCP、DGEBA/P2C1F-0.6DCP和DGEBA/P3C1F-0.6DCP均能通过V-0级别并且LOI值均在29%左右。锥形量热仪测试结果表明,DGEBA/P1C1F-0.6DCP、DGEBA/P2C1F-0.6DCP和DGEBA/P3C1F-0.6DCP的热释放速率峰值(pHRR)分别比DGEBA/DDM降低了68.4%、64.7%和70.7%。通过炭渣的形貌和结构分析,含磷腰果酚基羟基型固化剂的阻燃机理在于能够在燃烧过程中促进形成质量更高的炭渣,发挥更好的隔热、隔氧的效果。

With increasing environmental protection awareness, developing high-performance bio-based epoxy resins to reduce the dependence on the petroleum-based diglycidyl ether bisphenol A(DGEBA) and 4,4’-diaminodiphenylmethane(DDM) has attracted more and more attention. Three kinds of cardanol-based hydroxyl-type curing agents(P1C1F-0.6DCP, P2C1F-0.6DCP and P3C1F-0.6DCP) with adjustable functional group number were synthesized based on cardanol, phenol, formaldehyde solution, and diphenyl chlorophosphate. Corresponding research was carried out on their flame-retardant epoxy resins. Vertical burning and limiting oxygen index(LOI) results showed that DGEBA/P1C1F-0.6DCP, DGEBA/P2C1F-0.6DCP and DGEBA/P3C1F-0.6DCP all could pass the V-0 level, and the LOI values were around 29%. The cone calorimeter test results showed the peak heat release rates(pHRR) of DGEBA/P1C1F-0.6DCP, DGEBA/P2C1F-0.6DCP and DGEBA/P3C1F-0.6DCP were 68.4%, 64.7%, and 70.7% lower than that of DGEBA/DDM, respectively. Through the analysis of the morphology and structure of the carbon residue, the flame retardant mechanism of the phosphorus-containing cardanol-based hydroxyl-type curing agents was that they could promote the formation of higher quality carbon residue during the combustion process, and exert better heat insulation and oxygen barrier effects.