甲阶酚醛树脂的合成、表征及应用研究

Synthesis, Characterization and Application of Thermosetting Phenol-Formaldehyde Resin

利用NaOH作催化剂,合成了一类低游离酚/醛含量的甲阶酚醛树脂。研究了反应时间及催化剂用量对甲阶酚醛树脂的羟甲基含量、游离醛/酚含量以及粘均分子量影响。结果表明:随着反应时间的延长,树脂的羟甲基和游离酚含量降低,粘均分子量增大;增加催化剂用量会使游离酚和游离醛含量下降,催化剂用量对分子之间的缩聚反应类型有明显的影响。红外光谱结果表明:树脂的结构中含有羟甲基特征吸收峰。合成树脂用作粘结剂制备覆膜砂,并对覆膜砂的强度和性能进行了测试。由该合成树脂所混制的覆膜砂具有优越的使用性能,有望在覆膜砂生产中应用。

A thermosetting phenol-formaldehyde resin with low free phenol and formaldehyde content was synthesized by using of NaOH as the catalyst. The effect of reaction time and the amount of catalyst on hydroxymethyl content, free formaldehyde and phenol content, and the viscosity average molecular weight （Mη） was investigated. The results show that Mη increased with the reaction time increasing, while hydroxymethyl and free formaldehyde and phenol contents reduced. Free formaldehyde and phenol content declined with the raise of catalyst content, and the amount of catalyst will determine the type of polycondensation between molecules. The characteristic absorption peak ofhydroxymethyl was found in the infrared spectrum of the resin. The synthetic resin was used to produce the precoated sand and the performance of the coated sand was evaluated. The precoated sand prepared with the synthetic resin has excellent service performance and can be applied to the actual production.