【作者】 程珏；

【导师】 杨万泰；

【作者基本信息】 北京化工大学 ， 高分子化学与物理， 2007， 博士

【摘要】 利用表面光接枝方法制备的表面携带酸和特殊基团的膜片，研究了表面受限酸催化固化酚醛树脂和逐步接枝反应，阐明了其中涉及的基本原理和基本规律；同时合成了一种新的特种环氧树脂，并对其结构和热性能进行了详细地分析和表征，具有重要的理论意义和实用价值。主要研究进展和成果如下：采用UV表面接枝方法将丙烯酸(AA)接枝在LDPE膜表面，制备了含有羧酸的LDPE-g-PAA膜片。这种表面受限酸可催化甲阶酚醛树脂发生固化反应，膜表面固化层厚度为20nm—60nm。实验和分析结果表明：随着反应时间和反应温度的增加，固化层厚度虽有增加，但变化不大，所以，受限羧酸基团对酚醛树脂的固化有催化作用，但催化作用比较弱。通过对氨基苯磺酸与LDPE-g-PAA上羧酸的成盐反应，制备了农面含磺酸基团的膜片，羧基反应转化率大于30％。当膜片与酚醛树脂溶液接触反应时，溶液粘度无升高的结果表明这种酸催化固化作用只发生在膜表面——磺酸的受限区域内；膜表面酚醛树脂固化层重量和厚度随反应时间的增加和温度升高而明显增加，反应时间从1h增加到10h(50℃反应)，固化层厚度从127nm增加提高到234nm；反应温度从22℃升高到50℃时(反应时间2h)，固化层厚度从87nm加到154nm；改变溶剂性质，催化固化反应作用差别很大，在水介质中，磺酸对酚醛树脂有很强的催化固化作用，酚醛树脂固化层厚度为40nm—90nm，随反应时间延长固化层厚度增加，而同样条件下在丙酮介质中，酚醛树脂层的厚度只有20-30nm，而且延长反应时间对酚醛树脂层厚度没有影响。根据上述实验结果，提出表面受限磺酸作用于酚醛树脂的模型，磺酸中的氢离子被束缚在膜的表面，由于电荷作用，氢离子被酸根控制的距离为L，L的大小受温度和溶剂的影响，当温度升高时，L值变大，当温度降低时，L值变小：当溶剂能够很好地溶解LDPE膜表面的大分子链以及磺酸根基团时，L值变大，而当溶剂的性质与大分子链或磺酸根基团的溶解性不相近时，L值变小。这种机理很好地解释了本章研究发现的各种实验现象。将LDPE-g-PAA与亚硫酰氯反应制备了表面含酰氯基团的膜片，确定了合适的反应条件；通过对酰氯基团在各种介质中稳定性的比较，确定丙酮作为酰氯基团进一步与其它试剂反应的溶剂：在聚合物膜片表面接枝了间苯_二酚，形成了逐步聚合的锚点，扩大了膜表面接枝反应在机理和单体领域的范围：设计了一种膜表面逐步缩合接枝反应方法，将表面带有特殊基团的膜片交替放入间苯二酚、甲醛(丙酮)溶液中，实现了逐步缩合反应只在膜片表面发生，同时也为其他逐步聚合反应的理论研究提供一种新方法。发明了以水为溶剂间苯二酚与丙酮反应合成多官能度酚的方法，并证明该多酚结构是一种三官能度酚——4-(3，3-二氢-7-羟基-2，4，4-三甲基-2H-1-苯并吡喃-2-基)-1，3-苯二酚，该方法具有合成体系简单、无溶剂污染、目标产物纯度高(大于94％)和单体的转化率高(大于99％)的特点，并提出了间苯二酚与丙酮反应生成一种邻-异丙烯基酚，然后异丙烯基酚发生二聚，最后二聚体闭环生成苯并氧杂六环结构的反应机理。进一步采用该酚与环氧氯丙烷反应合成了的特种环氧树脂(TF-EPOXY)，通过FTIR和ESI-MS确定了环氧树脂的结构是与三官能度酚相对应的三官能度环氧树脂。采用二氨基二苯砜(DDS)和二氨基二苯甲烷(DDM)固化三官能度环氧树脂，同化动力学研究得出固化反应活化能分别为63.2kJ／mol和55.3kJ／mol，同化反应级数分别为0.875和0.882。确定了固化反应的适宜温度分别为200℃-250℃和150℃-200℃。采用DSC、DMTA和TG分析了TF-EPOXY／DDS和TF-EPOXY／DDM体系的耐热性能，结果表明：两种固化体系的Tg均为300℃，比同体系的普通环氧树脂Tg高出100℃左右，是一种新型的耐高温的高性能环氧树脂品种。更多还原

【Abstract】 Surface photo-grafting has been considered as a promising way to prepare a kind of film on the surface of which there are acids groups and novel reactive groups. The catalysis curing reactions of phenolic resole and stepwise grafting reactions induced by confined acids and novel groups were studied to explore and understand the basic principles. Meanwhile, a novel multi-phenol and new novel epoxy compound was synthesized, and their structures and thermo-resi stance property were analyzed and characterized. The main achievements are as following:The films with carboxyl group on the surface were prepared by the UV photo-grafting of acrylic acid onto LDPE films. Resultant surface confined acid can catalyze the curing reaction of phenolic resole. Calculated thickness of curing phenolic resole layer was between 20nm and 60nm. The reaction time and reaction temperature dependence of catalysis curing effect of confined acid on phenolic resole demonstrated that the thickness of curing phenolic resole layer increased slightly, which clarified the catalytic effect of confined carboxyl groups on the curing of phenolic resole were not power enough.The films with sulfonic groups on the surface were prepared by the reaction of carboxyl groups in LDPE-g-PAA and sulfanic acid with conversation of carboxyl groups more than 30%. The viscosity of phenolic solution kept constant when films were soaked into the solution, which revealed the curing reaction of phenolic resole occurred only on the surface or the vicinity of sulfonic groups in stead of in the solution of phenolic resole. The weight and the thickness of cured phenolic resole layer on the surface of films were increased with the increase of reaction temperature and reaction time. Cured phenolic resole layer was increased from 127nm to 234nm when the reaction time changed from 1 hour to 10 hours at 50℃, and from 87nm to 154nm when the reaction temperature rose from 22℃to 50℃. The catalysis effect of acid on the curing of phenolic resole varied obviously with the variation of solubility of solvent. The thickness of curing phenolic resole layer thickened from 40nm to 90nm with increase of reaction time in water. Otherwise, the thickness of curing phenolic resole was only between 20nm to 30nm in acetone in the condition as the same as that in water. Consequently, an appropriate model of confined sulfonic acid was proposed. H proton was confined within a distance of L to a sulfonic group, which was influenced by reaction temperature and solubility of solvent. The value of L enlarged with the rise of temperature and better of solubility of solvent. This model can explain experimental phenomena reasonably.The films with acyl chloride on the surface were prepared by the reaction of LDPE-g-PAA and thionyl chloride. The reaction conditions were determined. The comparison of stability of obtained acyl chloride in several kinds of solvents was carried out and acetone was found to be appropriate one where the acyl chloride existed stably. The confined acyl chloride groups were used to graft resorcinol molecule successfully, which was expected to be a position for further condensation with some monomers with functional groups, such as formaldehyde and acetone. A new way was designed to undergo the stepwise grafting reaction by which resorcinol and formaldehyde (or acetone) was grafted alternatively to the surface of LDPE film. This method was also useful way for theoretical study of stepwise polymerization.A new way was invented for preparation of a tri-functional phenol by using resorcinol and acetone in water. It was of the feature of simple composition, high purity of product (more than 94%) and high monomer conversion (more than 99%). An appropriate mechanism of the reaction of resorcinol and acetone was proposed. Furthermore, tri-functional group phenol was used to make epoxy by reaction with epichlorohydrin. The structure and molecular weight measured by FTIR and ESI-MS clarified the synthesized epoxy compound was a corresponding tri-functional epoxy (TF-EPOXY). Then, kinetic study of curing behavior of this TF-EPOXY cured by DDS and DDM was determined. Suitable curing temperature and curing activation energy were determined by DSC analytical results which were 200℃-250℃and 63．2kJ/mol for TF-EPOXY/DDS system and 150℃-200℃and 55．3kJ/mol for TF-EPOXY/DDM system respectively. Finally, the properties of heat resistance of TF-EPOXY / DDS and TF-EPXOY/DDM were elucidated by DSC, DMTA and TG analysis. The experimental results showed that Tg of TF-EPOXY/DDS system and CYD128/DDM were both more than 300℃, which were 100℃higher than that of BIS-A epoxy system. The synthesized novel epoxy compound was new species with thermo-resistance and high property.更多还原