萘-水杨醛沥青树脂的合成研究

Synthesis of naphthalene-salicylaldehyde pitch resin

以萘为单体,水杨醛为交联剂,在对甲基苯磺酸催化作用下合成了一种新型的萘-水杨醛沥青树脂。采用FT-IR研究了反应机理;采用TGA分析了合成树脂的热失重行为;通过单因素实验,考察了合成条件对沥青树脂收率、软化点和结焦值的影响规律。结果表明,萘与水杨醛在酸催化下发生了阳离子型缩聚反应;萘-水杨醛沥青树脂适宜的合成工艺条件为:萘和水杨醛的物质量比为1∶1,反应温度为150℃,反应时间为300 min,催化剂用量为10%。在此条件下,合成沥青树脂的收率为81.4%,软化点为79.6℃,结焦值为29.3%。水杨醛中羟基的位阻作用,有利于合成低软化点的沥青树脂黏结剂。

A novel naphthalene-salicylaldehyde pitch resin has been synthesized using naphthalene as monomer and salicylaldehyde as cross-linking agent in the presence of p-toluene sulfonie acid. FT-IR was used to study the reaction mechanism. The ther- mal weight loss behavior of the synthesized resin was characterized by TGA. The effects of synthesis conditions on the softening point and coking value of the pitch resin as well as its yield were investigated by single factor experiments. The results showed that the re- action of naphthalene and salicylaldehyde is a positive ion-typed condensation polymerization catalyzed by acid. The suitable conditions for synthesizing the naphthalene-salicylaldehyde pitch resin were： the amount of substance ratio of 1：1, the reaction temperature of 150 ℃, the reaction time of 300 min and the usage of catalyst 10%. Under the optimal conditions, the pitch resin exhibits the yield of 81.4%, the softening point of 79.6℃ and the coking value of 29.3%. The steric effect of hydroxyl group in salicylaldehyde is helpful to synthesize pitch resin binder with low softening point.