PhN-DOPO改性环氧树脂的制备及性能

Preparation and properties of PhN-DOPO modified epoxy resin

摘要:

以对氨基苯甲酸（PABA）、对羟基苯甲醛和9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）为原料合成了一种长链阻燃剂（PhN-DOPO），并经FTIR、1HNMR、ESI-MS表征确认。制备了PhN-DOPO添加量（加入质量为环氧树脂质量的百分数，下同）为0%、5%、10%、15%的系列梯度改性环氧树脂（EP1~EP4），通过DSC、TGA、极限氧指数（LOI）、垂直燃烧（UL-94）和粘接性能测试考察了改性环氧树脂的热稳定性、阻燃性及粘接强度。结果表明，PhN-DOPO添加量为10%时，改性环氧树脂EP3的玻璃化转变温度（Tg）提高至177.2 ℃，UL-94测试为V-0等级，LOI达32.4%，表现出最好的阻燃性和良好的热稳定性；EP3的粘结强度为68.82 N，比纯环氧树脂（EP1）高6.89 N。改性环氧树脂燃烧时，PhN-DOPO通过凝聚相和气相阻燃协同作用提高了环氧树脂的阻燃性，并且因为改性环氧树脂残炭的石墨化程度下降，所以其气相阻燃效果更为显著。

Abstract:

A long chain flame retardant (PhN-DOPO) was synthesized from p-aminobenzoic acid, p-hydroxybenzaldehyde and 9,10-dihydro-9-oxa-10-phosphame-10-oxide (DOPO). The results were confirmed by FTIR, 1HNMR and ESI-MS characterization. A series of gradient modified epoxy resins (EP1~EP4) with the addition amount of PhN-DOPO (the addition mass was the percentage of the mass of epoxy resin, the same below) of 0%, 5%, 10% and 15% were prepared. The thermal stability, flame retardancy and bond performance of the modified epoxy resin were investigated by DSC, TGA, LOI, UL-94 and bonding properties. The results showed that the glass transition temperature (Tg) of the modified epoxy resin EP3 increased to 177.2 ℃, the UL-94 test was V-0 grade, and the LOI reached 32.4%, which showed the best flame retardancy and good thermal stability when the PhN-DOPO content was 10%. The bond strength of EP3 was 68.82 N, 6.89 N higher than that of pure epoxy resin (EP1). During the combustion of the modified epoxy resin, PhN-DOPO improved the flame retardancy of the epoxy resin through the synergistic effect of condensed phase and gas phase flame retardancy, and the gas phase flame retardancy of the modified epoxy resin was more significant because the degree of graphitization of the residual carbon was reduced.