【作者】 何伟；

【导师】 蹇锡高； 廖功雄；

【作者基本信息】 大连理工大学 ， 材料学， 2006， 博士

【摘要】 新型含二氮杂萘酮联苯结构聚芳醚砜酮是本课题组近年来开发成功的一类高性能工程塑料,是目前耐热等级最高的可溶性聚芳醚新品种,性能价格比优异,具有很好的应用前景。但在加工生产及应用中该类纯树脂材料显示出一些不足之处,比如熔体粘度高导致热成型加工困难,材料脆性较大等,极大地限制其推广应用,因而需要进行改性。据此,本论文采用熔融共混及溶液共混方式对含二氮杂萘联苯结构聚芳醚类树脂进行改性,系统研究了改性材料的结构和性能关系,以期为将来工业化生产和应用提供理论依据。 采用逐步聚合方法制备了新型特种工程塑料含二氮杂萘酮结构的聚芳醚砜酮PPESK(S/K=50/50)、聚芳醚砜(PPES)及聚芳醚酮酮(PPEKK)。利用热失重(TGA)分析仪,氮气氛围中,多重加热扫描速率下的不定温法对PPESK(50/50)、PPES及PPEKK进行热分解动力学研究。根据Satava法得出,聚合物PPESK(50/50)分解反应机理为随机成核和随后生长,反应级数n=1;而聚合物PPES的热分解反应机理为相界面反应模式,反应级数n=2;PPEKK的热分解机理为三维扩散(3D);同时采用经典动力学方程Friedman、Kissinger-Akahira-Sunose(KAS)及Ozawa计算了热分解动力学参数(Ea,lnz)。重点考察不同升温速率、酮/砜比对PPESK(50/50)、PPES及PPEKK的热稳定性影响,并且根据得到的动力学参数推测其在高温使用条件下的使用寿命及对热分解反应过程中“动力学补偿效应”(KCE)进行分析。 采用动态热机械分析仪(DMTA)对新型含二氮杂萘酮结构聚芳醚砜(酮)及与聚四氟乙烯(PTFE)共混物,进行动态热机械性能表征。研究结果表明:新型含二氮杂萘酮结构聚芳醚砜酮PPESK的热稳定性能良好,在较高温度范围内储能模量保持在相对较高值,能较好的作为结构件使用。新型含二氮杂萘酮结构聚芳醚砜酮PPESK(S/K=80/20)的耐热性比新型含二氮杂萘酮结构聚芳醚砜酮PPESK(S/K=20/80)好,这是由于前者的砜基/酮基的比例比后者高,而砜基的键能比酮基的键能较高所致。另外,随着扫描频率的提高,PPESK的α松弛峰移向高温。PPESK(20/80)中共混加入10%PTFE可提高其玻璃化温度,但当含量大于10%后,共混体系的玻璃化温度(T_g)并不随着PTFE含量的增加而继续提高。同时采用Arrhenius方程计算PPESK(20/80)及其共混物α转变时分子运动活化能。 利用动态热机械仪(DMTA)及热失重仪(TGA)对采用熔融挤出方法制备的新型含二氮杂萘酮联苯结构聚芳醚砜酮PPESK(80/20)与聚醚砜(PES)共混物进行研究。动态热机械性能表明,加入PES对PPESK(80/20)的热稳定性有较大影响。另外,动态机械性能表明,在所研究的组分范围内共混物只有一个玻璃化转变温度,并随着PPESK(80/20)含量增加而升高,表明两组分完全相容。采用热失重仪测试PPESK(80/20)/PES共混物的热失重来分析更多还原

【Abstract】 Poly(ether sulfone ketone) containing phthalazinone moieties, a series of novel high performance polymer developed by our teamwork, have much better thermal resistance and solubility than similar high performance polymers. For better properties, the polymers have a strong competitive capability in international market. However, the pure resin shows some shortcomings in processing and application. For example, the melt viscosity is too high to process and the brittleness is unbeneficial to commercialization. Therefore, blending PPESK with other high performance polymers was adopted to improve their properties. In this paper, structures and properties of their blends were studied systematically, which was foundations in their industrialization and application.The kinetics of thermal degradation of poly (phthalazinone ether sulfone) (PPES)、 poly (phthalazinone ether sulfone ketone) PPESK(50/50) and poly(phthalazinone ether ketone ketone) in nitrogen were studied at several heating rates by thermogravimetry analysis (TGA). According to Satava method, the thermal degradation mechanism of PPESK(50/50) is randomly nucleating and nucleus growth, and order of reaction n=l. The thermal degradation mechanism of PPES, however, is phase boundary controlled reaction and order of reaction n=2 and the three dimensions dispersion for PPEKK. The kinetic parameters, including the reaction active energy and the frequency factor of degradation reaction for PPES、 PPESK(50/50) and PPEKK were analyzed by isoconversional Friedman, Kissinger-Akahira-Sunose(KAS) and Ozawa methods. The aim of this paper was to study on the effect of heating rates and ratio of ketone/sulfone on the thermal degradation and the life estimation. On basis of the kinetic parameters, the lifetime for high temperature has been calculated and the ’Kinetic Compensation Effects’(KCE) in the thermal degradation process was analyzed.In the present work, blends of poly (phthalazinone ether sulfone ketone) (PPESK) /poly(tetrafluoroethylene) (PTFE) with various weight ratios were prepared by solution mixing. The dynamic mechanical properties including the storage modulus(E’), loss modulus(E") and loss tangent were studied over a wide range of temperature and frequencies and compared for PPESK and its blends. The results show that novel PPESK possesses high storage modulus within a high temperature range and show good thermal stability. The peaks representing the loss modulus andtan d of blends shifted to higher temperatures with increasing scanning frequency. The thermal stability of polymer is increased with increasing the proportion of sulfone linkages in the backbone. And the Arrhenius relationship has been used to calculate the activation energy of the glass transition of PPESK and its blends.The mechanical and thermal properties of poly(phthalazinone ether suflone ketoneXPPESK)/poly(aryl ether sulfone)(PES) blends prepared by melt-mixing were investigated by dynamic mechanical thermal analysis(DMTA) and thermogravimetric analysis(TGA). The dynamic mechanical thermal analysis results show that the incorporated PES has a large influence on the heat stability of PPESK. The DMTA results display that the blends with a single glass transition temperature, which increases with increasing PPESK content, indicates that PPESK and PES are completely miscible over the studied composition range. The thermodegradative behavior of blends was used to analyze their thermal stability. The Friedman technique was used to determine the kinetic parameters i.e the apparent activation energy and order of reaction of the degradation process. On the basis of the kinetic data derived from Friedman’s approach, the lifetime estimates for pure PPESK, pure PES, and the blends generated from the weight loss of 5% were constructed.Miscibility and thermal properties of PPESK/ polyarylate (PAR) have been investigated using differential scanning calorimetry (DSC), DMTA, scanning electron microscope(SEM) and TGA. These blends show a single and composition-dependent glass transition temperature over the entire composition range by DSC method. However, it showed that these blends are partially miscible by DMTA. Thermodegradative behaviour of blends was studied by dynamic thermogravity in order to analyze their thermal stability. The Friedman method was used to determine the kinetic parameters-the apparent activation energy (Ea). The results indicate that the presence of one component influences the thermal stability of the other. Temperature for 5% weight loss, and Ea for blends show a negative deviation from the linear behaviour, which signifies a lowering of thermal stability compared to homopolymers.Artificial neural network (ANN) was applied to forecast the properties of composites based on PPESK. Samples data of TK reinforced composites were applied to train the ANN by neural network tool of MATLAB 6.5. Back-propagation (BP) neural network was established and the optimum parameters of ANN were chosen. The properties of composites based on PPESK were forcasted by the trained ANN. The results show that the train ANN can exactly forecast the properties of composites. ANN based on MATLAB 6.5 also offers an efficient and credible method for analyzing the effect of components.更多还原