材料期刊网

合成了一种含磷酚醛型环氧树脂固化剂DCPD-DOPO,通过红外光谱和核磁共振谱对其化学结构进行了表征,采用凝胶渗透色谱测量了其相对分子质量.以DCPD-DOPO、苯酚型酚醛树脂(PF8020)或其复合物为固化剂,双酚A环氧树脂(DGEBA)为基料,制备了不同磷含量的阻燃环氧树脂.通过热重分析、差示扫描量热分析研究了环氧树脂固化物的热性能和阻燃性能;通过极限氧指数(LOI),垂直燃烧实验和锥形量热法研究了固化后环氧树脂固化物的燃烧特性.结果表明,DCPD-DOPO固化的环氧树脂的LOI可达31.6％,垂直燃烧性能达到UL94 V-0级,玻璃化转变温度(Tg)为133℃.采用DCPD-DOPO与PF8020复合物固化的环氧树脂的Tg提高到138℃以上,LOI值略有降低,但仍能通过UL 94 V-0测试.DCPD-DOPO与PF8020添加DCPD-DOPO后,复合固化的环氧树脂的热释放速率峰值及总释热量较PF8020固化的环氧树脂大幅度降低.此外,还用Kissinger法对环氧树脂固化反应动力学进行了研究.

A novel phosphorus-containing dicyclopentadiene novolac (DCPD-DOPO) curing agent for epoxy resins,was synthesized by the reaction of 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and nbutylateddicyclopentadiene phenolic resin (DCPD-E).FT-IR,1H-NMR,31p-NMR and gel permeation chromatography (GPC) were employed to characterize the synthesized compound.The flame retarded diglycidyl ether bisphenol A (DGEBA) epoxy resin with different phosphorus content was obtained by using DCPD-DOPO or the mixture of DCPD-DOPO and phenol-formaldehyde novolac resin (PF8020) as curing agents.Thermal properties and flame retardancy of the cured epoxy resins were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).Limiting oxygen index (LOI),UL94 vertical test,and cone calorimeter were used to study the flame retardancy of the cured epoxy resins.The results show that the DCPD-DOPO cured epoxy resin possesses a LOI value of 31.6％ and achieves the UL 94 V-0 rating,while its glass transition temperature (Tg) is a bit lower 133 ℃.Tg of the epoxy resin cured with the mixture of DCPD-DOPO and PF8020 increases to 138 ℃ or above,and while the epoxy resin can still pass the UL 94 V-0 test.Cone calorimeter test indicates that the peak heat release rate and total heat release of the phoshoorus containing epoxy resin EPPF/DC/3/1 decrease sharply compared to those of EPPF.Moreover,the curing reaction kinetics of the cured epoxy resins was studied by Kissinger method.