高分子量可交联聚芳醚腈的结构与性能关系研究

发布时间：2018-06-20 19:46

本文选题：聚芳醚腈 + 邻苯二甲腈封端　；参考：《电子科技大学》2017年博士论文

【摘要】：聚芳醚腈因其分子结构中含有刚性的基团及耐热性的氧醚键而表现出优异的力学性能、电性能、耐化学腐蚀性能、耐磨性、尺寸稳定性、无毒等优点。同时,由于强极性基团氰基侧基的存在赋予其与许多物质具有良好的粘结性,为制备高性能功能化复合材料提供了良好的基础,因此聚芳醚腈在商业界和学术界引起了广泛关注。但是传统的聚芳醚腈是一类线性的热塑性工程塑料,其耐热性和刚性较差。随着高科技及军事军用等的长足发展,耐超高温材料及自阻燃材料的研发迫在眉睫,目前,唯一满足美国海军阻燃标准的高分子材料是邻苯二甲腈聚合物。但邻苯二甲腈树脂作为一类热固性工程塑料,其成型加工性较差。因此,本文基于以上研究背景,结合了聚芳醚腈和邻苯二甲腈树脂的优点,合成了一种邻苯二甲腈封端的可交联聚芳醚腈,其在高温热处理前可采用热塑性材料的加工工艺制备各种形状的材料,再经过高温热处理使其具有与热固性树脂相媲美的耐高温性,而研究可交联聚芳醚腈的结构与性能之间的关系对聚芳醚腈的开发应用具有重要的指导意义。本论文首先通过分子设计,采用2,6-二氯苯甲腈与联苯二酚、对苯二酚为原料,其中联苯二酚适当过量,合成了酚羟基封端的聚芳醚腈,再通过4-硝基邻苯二甲腈与羟基进行亲核取代反应,合成了邻苯二甲腈封端的聚芳醚腈,即可交联聚芳醚腈,并利用核磁、红外光谱等手段对其结构进行了表征。联苯二酚过量的比例不同导致合成的聚芳醚腈具有不同的分子量。热处理前,分子量的大小对聚芳醚腈的热学性能、力学性能都有较大影响,而热处理后,由于交联反应使得分子量存在数量级差别的聚芳醚腈之间的热学性能、力学性能差距大大减小。同时,通过改变联苯二酚与对苯二酚的摩尔比,可得到不同结构不同性能的可交联聚芳醚腈。结果表明,随着对苯二酚比例的增加,聚芳醚腈的结晶能力逐渐降低,而联苯二酚与对苯二酚摩尔比为83:20的可交联聚芳醚腈在具有良好结晶能力的同时具有最佳的力学性能。通过流变、DSC、XRD等测试手段发现可交联聚芳醚腈中同时存在结晶行为与交联行为,因此本文采用DSC,利用Jeziorny法对可交联聚芳醚腈的结晶动力学进行了研究,得到结晶动力学参数,推测出可交联聚芳醚腈的晶体呈现类球状,并通过偏光显微镜和扫描电子显微镜对晶体形貌进行了验证。利用Kissinger法计算得到结晶活化能为152.7 KJ/mol,交联反应活化能为174.8 KJ/mol。同时,研究了热处理温度对聚芳醚腈交联反应及其性能的影响,发现随着热处理温度的升高,聚芳醚腈体系中的交联程度增大。在常压下,当热处理温度达到320℃时,由于交联反应较为剧烈从而抑制了晶体的生成,因此,适当的热处理温度是聚芳醚腈体系中结晶行为与交联行为并存的重要因素。在以上的研究基础上,通过热压法制备了可交联聚芳醚腈单组分复合材料,并对热压温度,热压时间对其性能的影响做了系统地研究。当温度小于280℃热处理时,由于交联反应十分缓慢,使得聚芳醚腈体系中产生大量晶体,在240-280℃温度范围内,随着热压温度的升高或热压时间的增加,可交联聚芳醚腈单组分复合材料的结晶度的变化较小,但其交联度随之大幅度增加,因此晶体通过无定型区的交联反应被固定在聚芳醚腈树脂中,从而提高了聚芳醚腈的综合性能。在该单组分复合材料中,晶体与交联点共同充当增强相,从而提高材料的力学性能和热学性能。最后,通过填料简单填充制备了二氧化硅增强聚芳醚腈复合材料,当纳米二氧化硅的填料为12 wt%时,复合材料的拉伸强度比纯聚芳醚腈薄膜增加了14%;通过溶剂热法制备了具有优异的吸波性能的聚芳醚腈/Fe_3O_4磁性杂化微球,由于Fe_3O_4磁性杂化微球表面具有氰基基团,因此可以和聚芳醚腈基体树脂在高温下发生交联反应,从而制备了具有磁性的聚芳醚腈/杂化微球复合薄膜;最后,还制备了聚芳醚腈/GO-CNT高介电复合材料,在铜离子与羧基的络合作用下,氧化石墨烯与酸化碳纳米管组合成三维结构,并且在高温下,在铜离子的存在下,聚芳醚腈发生交联反应形成了酞菁铜,从而得到了具有高介电常数、高强度的聚芳醚腈复合材料。综上所述,高分子量可交联聚芳醚腈这种新型的特种高分子在高新技术领域中将具有不可小觑的潜在应用。
[Abstract]:Poly aryl ether nitrile has excellent mechanical properties, electrical properties, chemical corrosion resistance, wear resistance, dimensional stability and non-toxic, because of its rigid group and heat resistant oxygen ether bond in its molecular structure. At the same time, the presence of the strong polar group cyanide side group gives it good bonding with many substances, and is prepared for high performance. The functionalized composites provide a good foundation, so polyaronitrile has attracted wide attention in the business and academic circles. However, the traditional polyaryl ether nitrile is a class of linear thermoplastic engineering plastics, whose heat resistance and rigidity are poor. With the rapid development of high technology and military military, the research of super high temperature resistant materials and self flame retardant materials At present, the only polymer that meets the flame retardant standard of the United States Navy is the polymer of phthalic two methonitrile. But phthalonitrile resin as a kind of thermosetting engineering plastics has poor processing property. Therefore, based on the above research background, this paper combines the advantages of poly (aryl ether nitrile) and phthalonitrile resin and syntheses a kind of neighbor. Crosslinked polyaryl ether terminated by benzonitrile, which can be prepared by the processing of thermoplastic material before heat treatment at high temperature, and then heat treated by high temperature to make it comparable to thermosetting resin. The relationship between the structure and properties of the crosslinked poly (aryl ether) nitrile is studied on the opening of polyaryl ether nitrile. In this paper, 2,6- two chlorobenzonitrile and dihydroxybenzene and hydroquinone are used as raw materials by molecular design. The Polyarylonitrile is synthesized by the proper overdose of dihydroxybenzene, and then the nucleophilic substitution reaction of 4- nitrophthalonitrile and hydroxyl group is used to synthesize phthalic two methonitrile. Poly aryl ether nitrile can be crosslinked with poly aryl ether nitrile, and its structure is characterized by NMR and IR. The proportion of overdose of diphenylene diphenolol has different molecular weight. Before heat treatment, the molecular weight has great influence on the thermal and mechanical properties of polyaryl ether and heat treatment. After the crosslinking reaction makes the thermal properties between the molecular weight and the molecular weight of the polyaryl ether, the gap between the mechanical properties is greatly reduced. At the same time, by changing the molar ratio of dihydroquinone and hydroquinone, the crosslinked polyaryl ether with different structures and different properties can be obtained. The results show that the polyaryl ether is increased with the increase of the ratio of hydroquinone. The crystallization ability of nitrile gradually decreased, while the crosslinking poly (aryl ether nitrile) of dihydroquinone and hydroquinone molar ratio of 83:20 had the best mechanical properties at the same time. By rheology, DSC, XRD and other testing methods, the crystallization behavior and cross-linking behavior existed in the crosslinking poly aryl ether nitrile. Therefore, the use of DSC was used in this paper. The crystallization kinetics of crosslinked poly (aryl ether nitrile) was studied by Jeziorny method. The crystallization kinetics parameters were obtained. It was deduced that the crystal of Crosslinkable Poly aryl ether nitrile showed spherical like shape. The crystal morphology was verified by polarizing microscope and scanning electron microscope. The crystallization activation energy was 152.7 KJ/mol and cross-linking was calculated by Kissinger method. The reaction activation energy is 174.8 KJ/mol. and the effect of heat treatment temperature on the crosslinking reaction and properties of poly aryl ether nitrile is studied. It is found that the crosslinking degree in polyaryl ether nitrile system increases with the increase of heat treatment temperature. At atmospheric pressure, when the heat treatment temperature reaches 320, the crosslinking reaction is more intense and the formation of the crystal is inhibited. Therefore, appropriate heat treatment temperature is an important factor in the coexistence of crystallization behavior and cross-linking behavior in polyaryl ether nitrile system. On the basis of the above study, the single component composite of Crosslinkable Poly aryl ether nitrile is prepared by hot pressing, and the influence of hot pressing temperature and hot pressing time on its properties is systematically studied. When the temperature is less than 280 degrees centigrade, the temperature is less than the temperature. When the crosslinking reaction is very slow, a large number of crystals are produced in the polyaryl ether nitrile system. The degree of crystallinity of the crosslinkable polyaronitrile composite is little changed with the increase of hot pressing temperature or hot pressing time in the temperature range of 240-280 C, but the crosslinking degree of the composite increases greatly, so the crystal passes undetermined. The crosslinking reaction of the type region was immobilized in the poly aryl ether nitrile resin, thus improving the comprehensive properties of polyaronitrile. In the single component composite, the crystal and crosslinking point acted as an enhanced phase, thus improving the mechanical properties and thermal properties of the material. Finally, the silica reinforced poly aryl ether nitrile composite was prepared by simply filling and filling the filler. Material, when the filler of nano silica is 12 wt%, the tensile strength of the composite is increased by 14% than that of the pure polyaryl ether nitrile film. The poly aryl ether nitrile /Fe_3O_4 magnetic hybrid microspheres with excellent absorbing properties are prepared by the solvent heat method. As the Fe_3O_4 magnetic hybrid microspheres have a cyanyl group in the surface mask, the poly aryl ether nitrile matrix tree can be used. A Polyarylonitrile / hybrid microsphere composite film with magnetic properties was prepared at high temperature. Finally, Polyarylonitrile /GO-CNT high dielectric composites were prepared. Under the complexation of copper ions and carboxyl groups, graphene oxide was combined with acidified carbon nanotubes into three dimensional structure, and the storage of copper ions at high temperature. At the same time, polyaryl ether nitrile occurs as a crosslinking reaction to form copper phthalocyanine, thus obtaining high dielectric constant and high strength poly aryl ether nitrile composite. In summary, high molecular weight crosslinked poly (aryl ether nitrile), a new special polymer, will have potential applications in high technology field.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O632.62

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