新型半芳香聚酰胺的合成与表征

【作者】 裴晓辉；

【导师】 赵清香；

【作者基本信息】 郑州大学 ， 材料学， 2005， 硕士

【摘要】 随着科学技术的飞速发展,为了解决电子产品的小型化、精密化和降低成本的问题,通常采用在集成电路板上搭载、连接半导体芯片和电子元件的工艺,故此,表面实装技术(SMT)得到迅速推广和普及。但这种新的技术对所使用的有机材料的耐热性、精密成型性及尺寸稳定性提出了更严格的要求。 聚酰胺在电子电器领域有着广泛的应用,为了适应对其耐热性、吸水率、尺寸稳定性等方面新的要求,人们在进行分子结构设计时可在分子主链上引入带有热稳定性好的芳香环,例如用芳香族酸或胺代替脂肪族酸或胺,来合成全芳香族或半芳香族聚酰胺。全芳香族聚酰胺由于熔点很高,成型加工极为困难,主要用于溶液法制造纤维。一些已应用的半芳香聚酰胺虽然熔点较低,容易加工,但耐热性能相对较差。最近开发出来的PA9T是以对苯二甲酸与较长碳链的壬二胺聚合得到的,其具有兼顾耐热性与加工性的优点,发展十分迅速。 利用本体聚合,我们合成了七种新型的半芳香聚酰胺,探索了聚合条件对反应的影响,并对其基本性能进行了研究,考察了产物的热分解、熔融结晶行为和结晶动力学,以期为新型耐热性聚酰胺的开发、研究打下基础。以上研究工作迄今未见报道,本研究工作得到了以下主要结果与结论: 1.以对苯二甲酸、间苯二甲酸、4,4’-联苯二甲酸、4,4’-二羧基联苯砜和4,4’-二羧基联苯醚分别与癸二胺和十二碳二元胺反应,合成了聚对苯二甲酰癸二胺(PA10T)、聚间苯二甲酰癸二胺(PA10I)、聚4,4’-二羧基联苯砜癸二胺(PA10S)、聚4,4’-二羧基联苯醚癸二胺(PA10O)、聚4,4’-联苯酰十二碳二胺(PA12B)、聚4,4’-二羧基联苯砜十二碳二胺(PA12S)和聚4,4’-二羧基联苯醚十二碳二胺(PA12O)等七种新型的半芳香聚酰胺,并对其基本性能进行了表征。 2.采用本体聚合时,聚合物粘数随反应温度的升高而增大,但反应温度过高时,聚合物粘数又有一定的下降;同一反应温度下,聚合物粘数随聚合时间的延长而增大,当时间延长到一程度后,增大趋势不大。最佳反应条件为:预聚合温度220℃,时间1～2h;聚合温度260～270℃,时间4～5h。对于PA10I,反应温度230℃,时间5h。 3.用偏光显微镜(PLM)研究了半芳香聚酰胺PA120、PA12S等溫熔体结晶的球晶形态及生成条件。发现随着结晶条件不同,可生成五种不同形态的球晶。 4.通过FTIR和~1H-NMR图谱分析,确定了这些产物是所要制备的半芳香聚酰胺。 5.用DSC对不同热处理方式处理的半芳香聚酰胺PA12O、PA12S的熔融行为进行更多还原

【Abstract】 With the rapid development of science and technology, the surface mount technology(SMT) was made general and universal application for making the electronic products miniaturization , precision and lower cost in semiconductor CMOS chips and electronic components which were jointed together on the integrated device electronics in the electron industry. Such a new technology bring a higher demand for the used organic materials, such as thermal tolerance , dimension precision and stability.One often introduces the aromatic rings into the organic macromolecular main chain to enhance polymer’s thermal tolerance and reduce their water absorption. For example, aromatic acid or aromatic amine was used in place of aliphatic acid or aliphatic amine to synthesize the aromatic or semi-aromatic polyamides. Aromatic polyamides were mainly used in manufacturing fibre, and difficult to mold. Some semi-aromatic polyamides, has a relatively lower melting point(T_m). Though it is easy for molding, but its thermal tolerance was not good enough. PA9T exploited recently was synthesized using terephthalic acid and nonane diamine owned combined merits of the heat-durability and the processing ability.In this study, we synthesized seven kinds of new semi-aromatic polyamides by bulk polymerization, The effect of polymerization condition on reaction was investigated. The thermal decomposition the behaviors of melting and crystallinity of product were studied. The above research works still have not been seen in the literature up to date. The results of our works summarized as follows:l.poly(decamethyleneterephthalamide)(PA10T),poly(decamethyleneisophthalam ide)(PA10I),Poly(dodecamethylene-biphenyldicarboxylic-amides)(PA12B), poly(decamethylene-dicarboxydiphenylether-amides)(PA 10O), poly(decamethylene -dicarboxydiphenylsulfone-amides)(PA10S),poly(dodecamethylene-dicarboxydipheny lether-amides)(PA12O),poly(dodecamethylene-dicarboxydiphenylsulfone-amides)(PA 12S) were synthesized using terephthalic acid, isophthalic acid, biphenyldicarboxylic acid , dicarboxydiphenyl ether acid , dicarboxydiphenyl sulfone acid with decamethylene diamine and dodecamethylene diamines. We studied some characters of these polymer.2. In bulk polymerization, the reduced viscosity of product increases withreaction temperature, but it will decreases under too high reaction temperature. In the same reaction temperature, the reduced viscosity increases with prolongation of reaction time. Optimal reaction condition was 220°C, 1 ~2h in the first step; then at the 260~270°C, for 4~5h. For PA10I, the reaction temperature was 230"C, for 5h.3. The morphology of semi-aromatic crystallization from melt was observed by PLM from Tg~Tm. Different spherulite forms were observed as varying the crystallization temperature and crystallization condition.4. The structures of polymerization products are ascertained by their spectrum of FTIR and ’H-NMR. The result show these products are semi-aromatic polyamides.5. The glass transition temperature (Tg), equilibrium melting point temperature and equilibrium heat of fusion of semi-aromatic polyamides were determined by means of differential scanning calorimetry (DSC). The equilibrium melting point temperature of semi-aromatic polyamides are to be 259.6°C(PA12O) and 275.4°C(PA12S) from the Hoffman’s method. In the DSC heating curves of isothermally melt crystallized from cold quenching, there are two crystals, Peak I is to be microcrystallite formation in the boundary layer between the larger crystallites, Peak II is the major crystal in the isothermal crystallization process.6. The TG results of semi-aromatic polyamides indicate that the thermal degradation process of semi-aromatic polyamides is one-step reaction. The activation energy of the solid-state process was determined using Kissinger and Flynn - Wall -Ozawa methods, the results are to be 247.5 ~249.3KJ/mol for PA12O and 213. 2 -214. 8KJ/mol for PA12S. Analysis of experimental results suggests the actual reaction mechanisms of semi-aromatic polyamides is Deceleration type.7. Nonisothermal crystallization kinetics of semi-aromatic polyamides were investigated by DSC. The nonisothermal crystallization process of semi-aromatic po;yamides PA12O and PA12S were analyzed by Jeziorny modified Avrami equation. The Avrami exponent n is greater, which indicate that the mode of nucleation and the growth of the nonisothermal crystallization are complicated and that the nucleation mode might include both homogeneous and heterogeneous. The activation energies (AE) of PA12O and PA12S were determined to be -173.7KJ/mol and -215.2KJ/mol, respectively, for the nonisothermal crystallization processes by the Kissinger’s methods.更多还原