【作者】 李强；

【导师】 林薇薇； 沈烈；

【作者基本信息】 浙江大学 ， 材料学， 2003， 硕士

【摘要】 近年来，酚醛树脂以它优异的电气性能、热性能以及机械性能在电器领域的应用占到了42％。然而两步法生产酚醛塑料要加入固化剂六亚甲基四胺（HTMA），而HTMA分解，残留在塑料制品中的游离氨会腐蚀电器的金属部分。为了延长仪表和电器产品的寿命，需要使用不会残留有氨的高性能酚醛塑料。目前，无氨高性能酚醛树脂及其模压料主要靠从国外进口，本文就此问题作了较为深入的研究，成功研制出具有优良性能的无氨固化的玻璃纤维增强的酚醛模塑。 本文分为三个部分：首先合成带苄基醚键的热固性酚醛树脂，然后制备粘土／聚合物纳米复合材料讨论其熔融插层和剥离行为，最后讨论各种因素对力学性能的影响。 一．带苄基醚键的无氨热固性酚醛树脂的合成。本章主要讨论了这种酚醛树脂的合成条件，并用FT-IR对其表征，还研究了它的凝胶时间随温度的变化。结果表明，合成的酚醛树脂中有大量醚键，常温下它的凝胶时间很长，固化速度慢，温度大于160℃后，醚键分解产生甲醛，促进固化，凝胶时间迅速减小，固化很快。 二．苄基醚热固性酚醛（resol）和有机土插层和剥离行为的研究。这部分讨论了不带苯环和带苯环的两种十八烷基季胺盐分别处理过的粘土（DK1和DK3）和苄基醚resol进行熔融插层，研究了温度、熔融时间、粘土含量制备方法对粘土001层间距的影响及其热性能。结果表明，DK3在树脂中较为稳定，能形成剥离型纳米复合材料，而DK1在树脂中不稳定，固化后，d₀₀₁反而会有所减小；两者插入过程都非常快；对DK3来说，在合成树脂过程中立即加入粘土和将树脂与DK3进行直接熔融插层的效果差别不大。 三．制备玻璃纤维增强的模压料，讨论了粘土含量、树脂中热固性酚醛和线型酚的比例对模压试样力学性能的影响。结果表明，当树脂含量为35％，树脂中novalac含量为30％时，样品的力学性能最好。在此条件下，采用DK1的复合材料的力学性能增加不明显，而采用DK3的复合材料的弯曲强度和冲击强度分别比未采用DK3的增加了34％和25％。更多还原

【Abstract】 Phenolic resin has been widely used in electrical and electronic appliance, automotive and other industry fields due to its excellent electric, thermal and mechanical performance. However, phenolic plastic (novolac) prepared with two-step method is mostly cured with HTMA and this curing process will release ammonia from HTMA, which will corrode the copper or brass parts. It is very necessary to develop a novel phenolic plastic without ammonia after curing, which it is mostly depended on importation now. The dissertation emphasizes on preparing a novel phenolic plastic cured without ammonia and aims at enhance the thermal and mechanical performance.The paper consists of the following parts: (1) synthesis of a novel resol with dibenzyl ether bond; (2) preparation of the phenolic resin/layered silicates nanocomposites (RPLSN) and investigating the melt intercalation and curing behavior; (3) discussing mechanical properties and its related influence factor.The synthesis conditions of the resol with dibenzyl ether bond are discussed in the first section and it is characterized by FT-IR and gel-time test. The results show that the gel time of the resol prepared in this paper is much longer than that of resol catalyzed with normal alkali such as ammonia and it is more stable when temperature is under 160 ; while temperature exceeds 160 , it cures very fast.Secondly, the intercalation and exfoliation behavior of two layered silicates modified by organic cation (DK1 and DK3) with the resol under different conditions is investigated. It is found that the intercalated structure of DK3 is preserved and exfoliated in cured RPLSN, while the resol intercalated in DK1 is deintercalated when it is cured. It is suggested that DK3 intercalated in the resol is more stable in the curing process than DK1. Conclusively, organic modifier used for layered silicate plays an important role in determining the stable nanostructure.Finally, glass-fiber reinforced phenolic nanocomposite is prepared and its mechanical properties are investigated. The results indicate that good mechanical properties are obtained under condition that the content of DK3 is 3wt% in resin, resin is consisted of the ratio of 3:7 (novolac: resol) and proportion of resin with reinforcer is 35/65.更多还原