HDI-BPA酚醛树脂的合成及应用性能

Synthesis and application properties of HDI-BPA phenolic resin

摘要:

以双酚A酚醛树脂（BPA酚醛树脂）和六亚甲基二异氰酸酯（HDI）为原料，在二月桂酸二丁基锡（DBTDL）催化作用下合成了HDI-BPA酚醛树脂（目标产物）。采用FTIR、1H NMR、GPC、有机元素分析等对HDI-BPA酚醛树脂的化学结构和相对分子质量进行表征，结果表明目标产物成功制备，其Mw为3376。另外还探讨了反应温度、反应时间、物料配比、催化剂用量等因素对目标产物中异氰酸酯基的含量及接枝率的影响。通过建立异氰酸酯基的含量和接枝率的二次回归方程，使用响应面分析法中的Box-Behnken Design（BBD）对HDI-BPA酚醛树脂的合成工艺进行优化，其最佳工艺条件为：反应温度32 ℃、反应时间为55 min、m（BPA酚醛树脂）∶m（HDI）∶m（DBTDL）=1∶4.759∶0.012。在此条件下，合成产物中异氰酸酯基的含量（质量分数）为25.51 %，接枝率为48.929 %。最后，在HDI-BPA酚醛树脂中加入固化剂，制备出HDI-BPA酚醛树脂胶黏剂。其最大粘结力达283.69 N，相对于BPA酚醛树脂胶黏剂的性能提升了3.7倍，表明HDI的加入可以显著地提高BPA酚醛树脂对低极性皮革基材的粘结性能。同时HDI-BPA酚醛树脂胶黏剂的接触角为93.5°，表现出较好的疏水和耐水性能。

Abstract:

HDI-BPA phenolic resin is synthetised by bisphenol A formaldehyde phenolic resin (BPA phenolic resin) and hexamethylene diisocy-anate (HDI) under the catalysis of dibutyltin dilaurate (DBTDL). The chemical structure and molecular weight of HDI-BPA phenolic resin are characterize by FTIR, 1H NMR, GPC and organic element analysis. The results show that HDI-BPA phenolic resin is suc-cessfully prepared and its Mw is 3376. In addition, the effects of reaction temperature, reaction time, material ratio and amount of cata-lyst on the content of isocyanate and grafting ratio in the target product are discussed. The synthesis process of HDI-BPA phenolic resin is optimize by Box-Behnken Design (BBD) in response surface methodology by establishing a quadratic regression equation of isocyanate content and grafting ratio. The optimum conditions are as follows: a reaction temperature of 32 °C, a reaction time of 55 min, a ratio of m (BPA phenolic resin), m (HDI) and m (DBTDL) of 1∶4.759∶0.012. Under this condition, the content (mass fraction) of the isocyanate group in the final product is 25.51 %, and its graft ratio is 48.929 %. Finally, a HDI-BPA phenolic resin adhesive is prepare by adding a curing agent to the HDI-BPA phenolic resin. Its maximum adhesion is 283.69 N, which is 3.7 times higher than that of BPA phenolic resin adhesives, indicating that HDI modification can significantly improve the adhesion of BPA phenolic resin to low polarity leather substrates. At the same time, the contact angle of HDI-BPA phenolic resin adhesive is 93.5°, which shows good hydrophobic properties and water resistance.