估算橡胶助剂溶解度参数用基团贡献值的研究

应用化合物的摩尔基团可加性原理，研究了估算橡胶助剂溶解度参数用的摩尔体积、摩尔内聚能、摩尔折射度和摩尔引力常数的基团贡献值。在现有文献的基础上，还扩充了２４种基团的１１０个贡献值。扩充后的基团贡献值，可分别用Ｆｅｄｏｒｓ，Ｌａｗｓｏｎ和Ｈａｎｓｅｎ法估算出迄今为止的大部分橡胶助剂的溶解度参数。     

计算聚合物内压和新溶解度参数的基团贡献法

将298.15 K时各种液态聚合物的内压平方根λ和重复单元的摩尔体积Vm的乘积对它们的van derWaals体积作图时,发现是一条通过坐标原点的直线.这意味着聚合物的λVm具有良好的基团加和性.据此,建立了一个能满意地预测聚合物内压的基团贡献法.结合Small的基团摩尔引力常数,该基团贡献法也能用来计算液态聚合物在298.15 K时的新溶解度参数值.     

基团溶解度参数及有机物汽化热的估算

为了使基团参数具有一值多用的性质,本文根据溶液的晶格理论,定义了基团溶解度参数,并利用该参数对有机物的汽化热进行了估算.结果表明,本文的方法在汽化热的估算精度上比现有的基团加和法在多数情况下有所提高.特别是,利用本文的方法还可以比较准确地估算多官能团有机物的汽化热.     

溶解度参数的发展及应用

介绍溶解度参数理论和计算方法的发展过程及其应用。Hildebrand J H提出溶解度参数理论后，经过三维溶解度参数以及后期的二维溶解度参数体系的发展与修正，溶解度参数已成为化工领域中的重要参数之一；溶解度参数的计算有试验与估算法和基团贡献计算法等；溶解度参数被广泛用于预测聚合物间的相容性、选择混合体系中的良溶剂及各类助剂等。     

磺化聚苯醚的制备

分别从磺化剂的用量、反应时间、反应温度、磺化剂滴加速度及搅拌速度等方面对磺化聚苯醚的影响因素进行了探讨,总结得到最佳的反应条件。     

EVM橡胶溶解度参数的理论计算及实验测定

采用理论计算和溶胀实验,研究了Levapren400,Levapren450,Levapren500和Levapren600 4种牌号的乙烯-醋酸乙烯酯共聚物(EVM)的溶解度参数。结果表明,4种不同醋酸乙酯含量的EVM,具有相似的溶胀性能,其溶解度参数的实验测定值与理论计算值相符,在18.00～21.00(J/cm3)1/2之间。确定了4种牌号EVM的良溶剂有甲苯(18.16)、氯仿(18.95)、四氢呋喃(19.46)、氯苯(19.58)和二氯甲烷(19.82)。     

基团法估算临界参数的改进

在系统整理大量临界数据的基础上，提出了临界性质的新基因估算法及基团贡献值，Ｔｃ，ＰｃＩｃ的平均误差分别为０．７６、４．２５、２．３３％，此结果优于作为比较的Ｊｏｂａｃｋ法。此外，本法还可用于长链化合物。     

溶解度参数在研制高性能丙烯酸聚氨酯涂料中的应用

本文采用革团贡献方法估算了双组份涂料中丙烯酸聚合物及固化剂HDI缩二毛的三维溶解度参数,并以此为基础选择了体系合适的溶剂：讨论了涂料成膜组份之间的相容性,分析了“雾影”的成因及消除“雾影”的方法,本实验将溶解度参数作为丙烯酸聚合物及其涂料配方设计的一项重要参数,并在此基础上制得了性能优良的丙烯酸聚氨酯涂料。     

UNIFAC法研究甲烷气体溶解度

用自建的一套设备测定了甲烷在异丙醇、丙酮、四氢呋喃、环己酮及乙酸甲酯中的高压溶解度。采用UNIFAC法对自测及文献中甲烷在极性纯溶剂中的溶解度数据进行了关联和估算,定义了新基团,并回归出了基团间的交互作用能量参数。结果表明,用文中得到的参数估算甲烷在相关溶剂中的溶解度数据结果良好。     

基团贡献法估算物性的进展

本文简述了基团贡献法的原理及其在基础物性估算中的应用，评述了基团贡献法的发展趋势。     

PPO的合成机理研究

通过高相对分子质量聚苯醚（PPO）的合成实验制备了一系列不同低相对分子质量的PPO产物,通过凝胶渗透色谱（GPC）监控PPO相对分子质量的变化,结合产物的产率系统研究了聚合过程的链增长机理。结果表明,链增长机理过程中,再分配和重排机理并不是一直同时存在的,此过程分为3个阶段：再分配链增长、重排与再分配链增长、再分配动态平衡;结合产率和GPC表征研究了链增长机理,合理解释了合成产物相对分子质量的控制情况,开辟了一种研究链增长机理的新思路。     

非等温热重法研究聚苯醚热分解动力学

采用非等温热重法对聚苯醚的热分解动力学进行研究,计算了反应活化能,采用积分法结合36种动力学函数来判断聚苯醚热分解的机理函数,得到了聚苯醚热动力学参数即反应的动力学函数,平均活化能（E_a）为211.64kJ/mol,指前因子（A）的平均值为6.24×10⁷s^-1,也获得了对应的热分解动力学方程。     

Recycling of Poly(phenylene ether) Blends

The effects of postindustry recycling of polymer blends composed of poly(phenylene ether) (PPE) on the properties of the PPE blends were investigated by simulated recycling with multiple molding cycles. Two compositions with different concentrations of PPE were reprocessed with an injection‐molding machine. Mechanical, thermal, rheological, and morphological characterizations were carried out on as‐produced and reprocessed samples to examine the influence of the number of molding cycles on the two specific PPE blends. Efforts were made to determine the effect of each molding cycle on the specific properties of the two PPE blends, including the Elastic (E), modulus, stress at break, strain at break, multiaxial impact, and melt viscosity. The results are discussed in detail. The retention of the properties correlated well with the unperturbed morphology of the compositions before and after recycling, as observed by transmission electron microscopy analyses on fractured tensile samples. However, more in‐depth microanalyses are required to identify the effect of recycling on the individual components present in the studied compositions. In this study, we aimed to establish structure–property relations upon recycling using several characterization techniques. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Poly(phenylene oxide)‐based polymer electrolyte membranes for fuel‐cell applications

Poly(phenylene oxide)s were synthesized by the oxidative polymerization of 2‐phenyl phenol (PP) and 2‐allyl phenol (AP). The copolymers were also synthesized with 80 mol % PP and 20 mol % AP and with equimolar monomers. The polymers were characterized. Blends of these polymers with poly(vinylidene fluoride) were prepared. These blend membranes were sulfonated, and their suitability for applications in fuel cells was evaluated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 307–311, 2003     

Crosslinkable poly(phenylene oxide) containing pendent 1,2-diphenylcyclopropane groups

Crosslinkable poly(phenylene oxide)s containing pendent 1,2-diphenylcyclopropane groups have been synthesized by oxidative polymerization from four new phenols containing the 1,2-diphenylcyclopropane group. The monomers were prepared by base-catalysed decomposition of the corresponding hydroxy-substituted 3,5-diphenyl-2-pyrazolines, which were the products of the reaction between hydroxy-substituted chalcones and hydrazine monohydrate. Characterization of and crosslinking studies on these polymers were carried out utilizing differential scanning calorimetry, thermogravimetric analysis, gel permeation chromatography and nuclear magnetic resonance. The polymers can be thermally cross-linked when heated to 350°C and the glass transition temperatures (T_g) of the polymers increase after crosslinking. The resulting crosslinked networks are insoluble in all solvents examined. Thermogravimetric analysis shows that no significant weight loss accompanies the crosslinking reaction.     

The preparation of microporous membranes from blends of poly(2,6‐dimethyl‐1,4‐phenylene oxide) and sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide)

Poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) is a chemically resistant polymer and, therefore, an attractive material for the formation of membranes. However, membranes of unmodified PPO prepared by an immersion precipitation possess very low hydraulic permeabilities at the filtration processes. The membranes with higher hydraulic permeabilities can be prepared from sulfonated PPO and/or from blends of unsulfonated PPO and sulfonated PPO. In conclusion, the mechanism of the formation of membranes from blends of unsulfonated PPO and sulfonated PPO is suggested. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 161–167, 1999     

Preparation and performance testing of sulfonated poly(phenylene oxide) based composite membranes for nanofiltration

Sulfonated brominated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPOBr) was synthesized by a sequence of bromination and sulfonation. A thin film of SPPOBr was coated on top of a commercial poly(ether sulfone) membrane. Pure butoxyethanol (BE) solvent or a BE/isopropyl alcohol (IPA) solvent mixture was used to dissolve SPPOBr in the coating process. The thin film composite membranes so prepared were then tested for the separation of carbohydrate and electrolyte solutes. We found that the flux and the carbohydrate separation both increased significantly with increasing IPA content in the solvent mixture. However, the separation of electrolyte solutes did not change significantly. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2624–2628, 2004     

Compatibilizing effect of functionalized polyphosphazene on the properties of poly(phenylene oxide)/vectra a blend system

The effect of functionalized polyphosphazene on the thermal, rheological, and morphological properties of PPO (poly(phenylene oxide))/liquid crystalline polymer (Vectra A) blend has been investigated by means of the capillary rheometry, mechanical testing, and scanning electron microscopy (SEM) in this study. The rheological measurements show that compatibilized blends exhibit substantial rise in viscosity in comparison to uncompatilized blend especially pronounced at lower shear rates which results in improved interfacial adhesion. DMA study highlights that polyphosphazene could be used as an effective compatibilizer for the concerned blend system. SEM study reveals fine fibrillation of liquid crystalline polymers in presence of compatibilizer and the fibers are oriented in the direction of flow field. The mechanical properties of the ternary blends are increased when a proper amount of polyphosphazene is added. This is attributed to fine strand generation induced via the addition of polyphosphazene. Enhanced adhesion at the interface invokes better elongation in the ternary blends. However, mechanical properties deteriorate considerably when polyphosphazene content is 5 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Electrodeposition of insulating poly(phenylene oxide) films with variable thickness

Ability to control key characteristics of electrodeposited polymers plays a vital role for their applications. In this work the results on tailoring the thickness of electronically insulating poly(phenylene oxide) (PPO) type polymer films have been showed. Pinhole‐free PPO films with variable thickness in the range of 10–50 nm were grown by controlling the potential applied during the electrochemical polymerization on the surface of titanium nitride (TiN) substrates. The insulating properties of the PPO film were confirmed by testing its permeability to redox species by cyclic voltammetry. Thermal stability of the PPO films with different thicknesses was investigated by in‐situ spectroscopic ellipsometry up to 400 °C in various environments. This insight is important for the optimization of the PPO anneal conditions in order to remove the residual solvent and potentially improve the polymer chains stacking. Our results provide the basis for electrodeposition of PPO films with variable thickness for diverse applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44533.     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998