Traditional epoxy resins are made by the reaction of petroleum-based bisphenol A and epichlorohydrin. The disadvantages of these petroleum-based epoxy including certain biological toxicity and flammability. To solve these problems, we first synthesized a diphenol compound 3,5-(4-hydroxyphenyl)-2-pyrazoline (TPP), which was prepared by condensation reaction of bio-based chalcone with hydrazine hydrate to replace standard petroleum-based bisphenol A. Then it was condensed with epichlorohydrin under alkaline condition to form a fully aromatic pyrazoline ring epoxy (TPP-EP). For further research, we use 4,4′-diaminodiphenylmethane (DDM) as the curing agent. When compared with bisphenol A epoxy resin (DGEBA/DDM), TPP-EP/DDM possessed a higher glass transition temperature (233°C vs. 176°C), and even showed that the residual carbon (in N₂) and the storage modulus (at 30°C) increased by 201% and 74%, respectively. What’s more, TPP-EP/DDM system also had good inherent flame retardancy. The limiting oxygen index of TPP-EP/DDM was 33.1, reaching the V-0 level tested by UL-94. From the cone test, the THR, p-HRR, p-SPR and TSP values of TPP-EP/DDM systems also showed different degrees of reduction. Since TPP-EP contained tertiary amine active groups that could be used as a kind of catalytic curing agents for epoxy resins, thus the compound had certain self-curing properties. This work was of great significance for the synthesis of pyrazoline bio-based environmentally friendly flame-retardant epoxy resin.

传统的环氧树脂是通过石油基双酚A与环氧氯丙烷反应制得的。这些石油基环氧树脂的缺点包括某些生物毒性和可燃性。为了解决这些问题，我们首先合成了一种二酚化合物3,5-（4-羟苯基）-2-吡唑啉（TPP），该化合物是通过生物基查尔酮与水合肼的缩合反应代替标准的石油基双酚A制备的。然后在碱性条件下将其与环氧氯丙烷缩合形成完全芳族的吡唑啉环环氧化合物（TPP-EP）。为了进一步研究，我们使用4,4'-二氨基二苯甲烷（DDM）作为固化剂。与双酚A环氧树脂（DGEBA / DDM）相比，TPP-EP / DDM具有更高的玻璃化转变温度（233°C对176°C），甚至表明残留碳（以N计）₂）和储能模量（在30°C下）分别增加了201％和74％。而且，TPP-EP / DDM系统还具有良好的固有阻燃性。TPP-EP / DDM的极限氧指数为33.1，达到UL-94测试的V-0水平。根据锥度测试，TPP-EP / DDM系统的THR，p-HRR，p-SPR和TSP值也显示出不同程度的降低。由于TPP-EP含有叔胺活性基团，可以用作环氧树脂的催化固化剂，因此该化合物具有一定的自固化性能。这项工作对吡唑啉生物基环保阻燃环氧树脂的合成具有重要意义。