【作者】 杨逢春；

【导师】 李彦锋；

【作者基本信息】 兰州大学 ， 高分子化学与物理， 2010， 博士

【摘要】 芳香聚酰亚胺具有优异的热和化学稳定性、机械性能和电学性能。因此,被广泛应用于诸如电子、封装材料、复合材料和膜材料等领域。为了满足应用的需求,旨在改善聚酰亚胺材料加工性能所进行的可溶性聚酰亚胺的开发和研究已成为目前聚酰亚胺功能化研究中最引人注目的热点之一。本论文简述了聚酰亚胺的发展过程,并在分子水平上探讨了可溶性聚酰亚胺分子所具有的结构特点以及各种改性方法对聚酰亚胺溶解性的贡献,结合各种有利的因素,设计合成了一系列不对称芳香二胺,通过元素分析、红外光谱、核磁共振和质谱等现代分析表征手段对单体结构进行了分析和鉴定。基于新单体与四种芳香二酐—3,3′,4,4′-二苯醚四羧酸二酐(ODPA),3,3’,4,4’-二苯甲酮四羧酸二酐(BTDA),4,4′-(六氟异丙基)双邻苯二甲酸酐(6FDA)和均苯四酸二酐(PMDA)的聚合反应,制备了四个系列可溶性聚酰亚胺,利用元素分析、红外光谱等表征手段对所得聚酰亚胺的结构进行了全面的表征确认,并利用紫外及可见光谱、TGA、DSC、广角X射线衍射、溶解性能、机械性能和介电性能等测试对相应聚酰亚胺树脂或薄膜的各种性能进行了全面讨论。本论文的主要研究工作如下：1.以2-氯-5-硝基吡啶为起始原料,经两步反应成功制备了含氟不对称二胺单体5-氨基-2-(4-氨基苯氧基)-吡啶(AAP),并与一系列芳香二酐,通过“二步法”制备了一系列新型可溶性聚酰亚胺。这些聚酰亚胺在极性有机溶剂中都有比较好的溶解性能,同时具有优异的热性能和机械性能；从溶解性的测试结果可以得知,所合成的聚酰亚胺在普通溶剂中具有优异的溶解性能。2.以对硝基苯甲酰氯为原料,成功合成了两种新的芳香二胺单体：4-氨基-4′(4-氨基-2-三氟甲基苯氧基)-苯甲酮,并与一系列芳香二酐通过“二步法”聚合制备了两个系列新型可溶性聚酰亚胺。由二胺p-AAFP制备的系列聚酰亚胺薄膜具有优异的热性能,机械性能和较低的吸水率。3.以间硝基苯甲酰氯为起始原料,经三步反应成功合成了两种新型含三氟甲基不对称二胺单体3-氨基-4′(4-氨基-2-三氟甲基苯氧基)-苯甲酮和3-氨基-4′(4-氨基苯氧基)-苯甲酮,与一系列芳香二酐通过“二步法”聚合制备了一个系列新型含氟聚酰亚胺。这个系列的聚酰亚胺有较高的分子量、优异的溶解性能和热性能以及较低的介电性能。其热分解温度达到550℃,表明得到的该类聚酰亚胺具有很高的热稳定性。含三氟甲基的聚酰亚胺较不含三氟甲基的聚酰亚胺具有更好的溶解性和更低的吸水率。该类聚酰亚胺不但在非质子极性溶剂中,如DMF, DMAc及NMP中表现出优异的溶解性能,而且在低沸点的普通溶剂中也具有比较好的溶解性能。4.以3,3′-二羟基苯醚为起始原料,经两步反应成功制备了含氟不对称二胺单体3,3′-(4-氨基-2-三氟甲基苯)二苯醚,并与一系列芳香二酐,通过“二步法”制备了一系列新型可溶性聚酰亚胺。这些聚酰亚胺在极性有机溶剂中都有比较好的溶解性能,同时具有优异的热性能和机械性能,从溶解性的测试结果可以得知,所合成的聚酰亚胺在普通溶剂中具有优异的溶解性能。更多还原

【Abstract】 Aromatic polyimides possess excellent thermal and mechanical, electrical, and chemical properties. Therefore, they are being used in many applications such as electrics, coatings, composite material, and membranes. However, the commercial use of these materials is often limited because of their poor solubility, and high softening or melting temperatures. To overcome these problems, more and more attempts have been focused on the preparation of novel polyimides with improved properties.This paper summarizes the structural characteristics of polyimides with excellent properties, and analyzed the contributions of several structural modification methods to each aspect of polyimide properties. Four novel aromatic diamines were designed and prepared based on the viewpoint of molecular design, which structures were confirmed by elementary analysis, FT-IR, NMR and MS. Derived from the resulted diamines and dianhydrides such as 4,4’-(hexafluoroisopropylidene)diphthalic anhydride (6FDA),4,4’-Oxydiphthalic anhydride (ODPA),3,3’,4,4’-benzophenonete-Tracarboxylic dianhydride (BTDA) and Pyromellitic dianhydride (PMDA), four series of novel polyimides were successfully synthesized. The polymer constructions were confirmed by elementary analysis, FT-IR and 1H-NMR. Their solubility, thermal property, mechanical property, aggregate structures, and dielectric property were investigated and discussed.A series of new polyimides were synthesized from an unsymmetrical aromatic diamine, 5-amino-2-(4-aminophenoxy)-pyridine with various commercially available aromatic dianhydrides. The resulting polyimides exhibited excellent solubility in polar solvents, such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidinone. Meanwhile, we detected the influence of resonance structure of hydroxypyridine to lactam to the synthesis of pyridyl ether linkage monomer.A kinds of aromatic, unsymmetrical diamines with ether-ketone group, 4-amino-4’-(4-amino-2-trifluoromethylphenoxy)-benzophenone, were successfully synthesized with two different synthetic routes. Then, they were polymerized with 4,4’-oxydiphthalic anhydride,3,3’,4,4’-benzophenone tetracarboxylic dianhydride, and 2,2’-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride to form a series of fluorinated polyimides via a conventional two-step thermal or chemical imidization method. The resulting polyimides were characterized by measuring their solubility, viscosity, mechanical properties, IR-FT, and thermal analysis. The results showed that the polyimides had inherent viscosities of 0.48-0.68 dL/g and were easily dissolved in bipolarity solvents and common, low-boiling point solvents. Meanwhile, the resulting strong and flexible polyimide films exhibited excellent thermal stability, e.g. decomposition temperatures (at 10%weight loss) are above 575℃and glass-transition temperatures in the range of 218-242℃. The polymer films also showed outstanding mechanical properties, such as tensile strengths of 86.5-132.8 MPa, elongations at break of 8-14%, and initial moduli of 1.32-1.97 GPa. These outstanding combined features ensure that the polymers are desirable candidate materials for advanced applications.Two kinds of novel aromatic, unsymmetrical diamines with ether-ketone group, 3-amino-4’-(4-amino-2-trifluoromethylphenoxy)-benzophenone and 3-amino-4’-(4-aminophenoxy)-benzophenone, was successfully synthesized by two different synthetical routes and polymerized with various aromatic tetracarboxylic acid dianhydrides, including 4,4’-oxydiphthalic anhydride,3,3’,4,4’-benzophenone tetracarboxylic dianhydride, and 2,2’-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride, via a conventional two-step thermal or chemical imidization method to produce a series of fluorinated polyimides. The polyimides were characterized with solubility tests, viscosity measurements, mechanical properties tests, IR-FT, and thermogravimetric analysis. The polyimides had inherent viscosities of 0.54-0.77 dL/g and were easily dissolved in both polar, aprotic solvents and common, low-boilingpoint solvents. The resulting strong and flexible polyimide films exhibited excellent thermal stability, with decomposition temperatures (at 10%weight loss) above 573℃and glass-transition temperatures in the range of 222-251℃. Moreover, the polymer films showed outstanding mechanical properties, with tensile strengths of 86.5-121.6 MPa, elongations at break of 9-16%, and initial moduli of 1.26-1.97 GPa. These outstanding combined features ensure that the polymers are desirable candidate materials for advanced applications.A new aromatic ether diamine, bis[3-(4-amino-2-trifluoromethylphenoxy) phenyl] ether, was successfully synthesized via nucleophilic substitution reaction of 3,3’-oxydiphenol and 2-chloro-5-nitrotrifluoromethylbenzene, followed by a catalytic reduction. A series of new polyimides were synthesized from the diamine with various commercially available aromatic dianhydrides via a conventional two-stage process, i.e. ring-opening polyaddition forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The resulting polyimides exhibited good solubility in polar solvents, such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidinone, and common solvents such as chloroform, tetrahydrofuran upon heating, and possessed the inherent viscosities of 0.51-0.68 dL/g. The resulting strong and flexible films exhibited excellent thermal stability with the temperature at 10%weight loss is above 502℃and the glass transition temperature in the range of 191-232℃. The polyimides also were found to possess high optical transparency.更多还原