【作者】 陈红；

【导师】 余鼎声；

【作者基本信息】 北京化工大学 ， 高分子化学与物理， 2002， 硕士

【摘要】 苯并噁嗪／酚醛树脂共聚体是由线性酚醛树脂、苯酚和甲醛经缩合聚合反应制得的。该共聚体系是利用线性酚醛树脂上的酚羟基作为酚源合成出苯并噁嗪／酚醛树脂共聚体。研究该共聚体系的出发点是利用线性酚醛树脂固化温度较低的特点来降低苯并噁嗪树脂的固化温度，并探讨该体系的固化行为。对该共聚体系的固化规律和固化动力学的研究，迄今文献上尚未见有报道。 本文探讨了苯并噁嗪／酚醛树脂共聚体系的合成条件，考察了反应时间和反应物中酚／醛配比对体系分子量的影响，讨论了该共聚体系的最佳合成条件。实验结果表明，苯并噁嗪／酚醛树脂共聚体的合成是缩合聚合反应，体系的黏度对于合成的顺利进行至观重要。 通过DSC对苯并噁嗪／酚醛树脂共聚体的自催化固化行为进行了分析。采用Kissinger方程、Ozawa方程和差减微分法分析了在升温速度为2.5℃／min-20℃／min之间的共聚体系的非等温固化行为。结果表明，由于该共聚体系结构及固化行为的特殊性，固化体系不符合Ozawa方程，而Kissinger方程和差减微分法均能较好的分析共聚体系的固化行为。等温固化DSC分析的结果表明，该体系的起始固化温度非常敏感，固化速度非常缓慢。 热固性树脂的固化过程的相态变化对固化产物的综合物理性能有重要的影响。本文采用扭辫分析法(Torsional Braid Analysis，TBA)对苯并噁嗪／酚醛树脂共聚体进行分析。共聚体系的温度-力学TBA谱图分析表明，固化反应的温度主要在404.2K-451.7K之间进行。随着固化温度的提高，固化体系依次进入熔化转变区(339K-404.2K)；凝胶化转变区(404.2K-451.7K)和玻璃化转变区(451 .7K一566.8K)。与苯并嗯啧树脂相比，共聚体系的转变区所对应的温度均有很大程度的降低，次级玻璃化转变情况更复杂。 苯并蟋嗓树脂的分子结构设计幅度大。本文对蔡嗯嗦树脂的合成方法进行了研究，并且通过’H一NMR、FT-IR和DSC对该中间体的结构进行表征。采用一步法和二步法合成路线考察不同溶剂对产物成环率的影响，以探讨蔡嗯嗦树脂的最佳合成条件。更多还原

【Abstract】 In this paper, the copolymer of phenolic/benzoxazine is prepared by the reaction of the novolac, primary amines and formaldehyde. Considering the low curing temperature of navolac, the aim of this paper is to reduce the curing temperature of polybenzoxazine resin and study the rule of the curing behavior of the copolymer. The research on the curing of this copolymer has not been reported before to our best knowledgeThe synthesis condition of copolymer of phenolic/benzoxazine resin has been studied and the influence of reaction time and rate of phenol/ formaldehyde have been reviewed in this paper. The result showed that the visicocity of the system is the important factor to the successful process of synthesis and a best synthesis condition has been made.The behaviors of ring-opening copolymerization, which play very role in the properties of the thermoset resin, have been studies in the detail by isothermal and dynamic differential scanning calorimetry (DSC) and torsional braid analysis (TBA).In the dynamic DSC analysis, the activation energy and the order of the reaction are determined by using the difference-differentiation computational method. Kissinger equation, Ozawa equation and Freeman-Carroll equation has been introduced to deal with the data of DSC analysis. The result show that Kissinger and Freeman-Carroll equation suit to the copolymer system while Ozawa equation isadverse.By using the torsioal braid analysis (TBA), the isothermal and dynamic curing behaviors of the copolymer have been studies intensively. During the cure, the phase of the copolymer changes from liquid to glass, which is accompanied by two phenomena, gelation and vitrification. Compared with benzoxazine, the cure temperature of copolymer has been reduced and the secondary transition is more complicated.Benzoxazine resin has a wide molecular structure designment and a new kind of benzoxazine has been synthesized and characterized by ’H-NMR, RT-IR and DSC. In addition, two different synthesis processes and three solvent have been adopted to study the best condition of synthesis.更多还原