新型聚丙烯酸酯类柴油降凝剂分子模型的建立及验证

在前期工作得出的正构烷烃含量与浊点、冷滤点、凝点的定量关系模型基础上，选择柴油降凝剂的基团对柴油降凝剂分子结构进行了设计，得出了设计模型。结果表明，将含氮基团引入柴油降凝剂可以显著提高柴油降凝剂的性能。根据设计模型合成了一系列聚丙烯酸单酯和混合酯柴油降凝剂，并通过对柴油降凝剂的性能测试结果和自行设计的计算程序对设计模型进行了验证，结果表明，从柴油正构烷烃含量对柴油降凝剂的配比进行设计是可行的。     

聚丙烯酸丁酯-四氢呋喃稀溶液性质

<正> 聚丙烯酸酯是一类具有优良性能和广泛用途的高分子材料。为了探讨材料性能与分子结构的关系,我们用小角激光光散射法、膜渗透压法、稀溶液粘度法及高效体积排斥色谱法研究了聚丙烯酸丁酯的(PBA)稀溶液性质。订定了聚丙烯酸丁酯在四氢呋喃中的极限粘数-分子量关系式。估算了分子的无扰尺寸与热力学参数。证明该聚合物与聚苯乙烯在所用的色谱条件下符合流体力学体积普适标定关系。     

聚丙烯酸芴酯的电化学氧化交联反应及其表征

合成了侧链带有芴的聚丙烯酸芴酯(PFM),在含40%三氟化硼乙醚的二氯甲烷混合电解质溶液中,直接阳极氧化PFM获得了自支撑交联网状的聚(聚丙烯酸芴酯)(CPFM)薄膜.通过UV-Vis、FTIR和1H-NMR对CPFM结构进行了表征.荧光光谱表明得到的聚合物薄膜CPFM在415nm附近处具有强的荧光发射峰,表明聚丙烯酸结构的引入没有影响聚芴的蓝色发光性能并有利于提高聚合物薄膜的力学性能.TGA表明得到的CPFM薄膜具有良好的热稳定性。     

红外光谱测定丙烯酸聚合反应的定量研究

为在线定量测定丙烯酸聚合反应进程,本文采用红外光谱分析技术,以偏最小二乘法(PLS)、支持向量机回归(SVR)、人工神经网络(ANN)等方法对丙烯酸和聚丙烯酸建立定量分析模型。提出基于上述定量模型不同组合的集成模型方法,对五组不同加料量的聚丙烯酸聚合反应过程进行定量分析,验证红外光谱定量应用于聚合反应的预测准确性。结果表明红外定量分析方法在聚合反应进程分析中拥有良好的预测性能,不同定量方法中SVR-POLY对丙烯酸的平均预测误差最小(0.0022±0.0021),PLS、SVR-POLY、SVR-RBF、ANN组合的集成模型对聚丙烯酸的平均预测误差最小(0.0037±0.0046)。     

核壳型聚丙烯酸酯乳胶粒子及其乳液的研究进展

综述了目前制备核壳型聚丙烯酸酯乳胶粒子的常用方法,如种子乳液聚合法、无皂乳液聚合法、反相乳液聚合法、细乳液聚合法以及种子分散聚合法;分析了聚合工艺、单体种类、温度、乳化剂和引发剂种类及用量等因素对聚丙烯酸酯核壳乳液合成及性能的影响;并对聚丙烯酸酯核壳乳液的研究现状进行了归纳;最后,展望了聚丙烯酸酯核壳乳液的发展方向。     

聚丙烯酸酯的玻璃化温度的定量结构性质相关研究

提出了高分子的侧基顺拉模型 ,认为侧基的空间效应主要来源于侧基的轴向横截面积 .与侧基的轴向横截面积密切相关的是侧基的碳链分支数 .直接采用侧基碳链分支数作为侧基的空间效应参数 ,对 13种聚丙烯酸酯和 9种聚甲基丙烯酸酯的玻璃化温度进行了定量结构 性质相关研究 ,得到了良好的三参数模型 ,对聚丙烯酸酯和聚甲基丙烯酸酯的玻璃化温度分别进行回归分析 ,相关系数R2 =0 989(s =3 8K)和R2 =0 993 (s =4 8K) .该模型对 2 2种聚丙烯酸酯和聚甲基丙烯酸酯的合并计算的结果是R2 =0 980 (s =8 3K) .建立的模型参数计算简便 ,模型的稳定性和适应性较好 ,所有模型的标准误差均小于或接近实验误差 .     

混合溶剂对β-HMX结晶形貌影响的分子动力学模拟（英文）

为了解释混合溶剂对β-HMX结晶形貌的影响,采用分子动力学方法系统地研究了β-HMX晶体表面与混合溶剂(丙酮/γ-丁内酯和二甲基甲酰胺/水)的相互作用,体积比从1:3到3:1。使用修正的附着能模型预测了β-HMX在混合溶剂中的生长习性。结果表明:β-HMX晶体的(020)面与溶剂分子的相互作用最弱,混合溶剂对β-HMX不同晶面的作用变化,可以显著地改变β-HMX的晶体形态。通过比较β-HMX在不同体积比混合溶剂作用下结晶形貌的纵横比,发现混合溶剂为二甲基甲酰胺/水,其体积比为1:3时,有利于β-HMX晶体球形化。     

聚丙烯酸酯阴离子交换树脂分离EDTA形成配合物

稀土元素与EDTA形成配合物Ln(edta)，在阴离子交换树脂的作用下，稀土元素与EDTA有明显不同的结合性。使用强碱性的凝胶和大孔径聚丙烯酸酯阴离子交换树脂：Amberlite IRA 458和Amberlite 958；以及弱碱性凝胶聚丙烯酸酯阴离子交换树脂：Amberlite IRA-68对Nd^3 与EDTA形成的配合物中吸收和层析出Y^3 进行实验研究。实验表明，弱碱凝胶聚丙烯酸酯阴离子交换树脂Amberlite IRA-68比强碱凝胶聚丙烯酸酯阴离子交换树脂更有效。     

聚氨酯/聚丙烯酸酯复合乳液的研制进展

概述聚氨酯－聚丙烯酸酯复合乳液的制备方法。特别对聚氨酯－聚丙烯酸酯复合乳液共聚法作了较为系统的介绍和讨论。     

基于PSRK模型预测高分子溶液汽液平衡

为了更好地预测高分子溶液的汽液平衡,本文应用PSRK模型改进的混合规则[即将组合项(∑xiInb／bi)与原UNIFAC模型中的组合项(Flory-Huggins项)相抵消所获得的简化的混合规则]来计算方程的能量参数α。为了计入自由体积效应对高分子溶液的过量Gibbs自由能的贡献,在计算体积参bij时,将原混合规则中的指数修订为bij^1/2(bi^1/2 bj^1/2)/2。应用PSRK模型结合改进的混合规则预测二元高分子溶液体系的汽液平衡,结果表明新模型的计算精度是令人满意的。     

Isotherm analysis of phenol adsorption on polymeric adsorbents from nonaqueous solution

Macroporous poly(methyl methacrylate-co-divinylbenzene) (PMMA), interpenetrating polymer adsorbent based on poly(styrene-co-divinylbenzene) (PS) and poly(methyl methacrylate-co-divinylbenzene) (PMMA/PS), and macroporous cross-linked poly(N-p-vinylbenzyl acetylamide) (PVBA) were prepared for the adsorption of phenol from cyclohexane. The sorption isotherms of phenol on the three polymeric adsorbents were measured and fitted to Langmuir and Freundlich isotherms. It is shown that the Langmuir isotherm, which is based on a homogeneous surface model, is unsuitable to describe the sorption of phenol on the adsorbents from nonaqueous solution and the Freundlich equation fits the tested three adsorption systems well. The isosteric enthalpy was quantitatively correlated with the fractional loading for the sorption of phenol onto the three polymeric adsorbents. The surface energetic heterogeneity patterns of the adsorbents were described with functions of isosteric enthalpy. The results showed that the tested three polymeric adsorbents exhibited different surface energetic heterogeneity patterns. The initial isosteric enthalpy of phenol sorption on polymeric adsorbent has to do with the surface chemical composition and is free from the pore structure of the polymeric adsorbent matrix. Forming hydrogen bonds between phenol molecules and adsorbent is the main driving force of phenol sorption onto PVBA and PMMA adsorbent from nonaqueous solution. When phenol is adsorbed on PMMA/PS, pi-pi interaction resulting from the stacking of the benzene rings of the adsorbed phenol molecules and the pendant benzene ring of adsorbent is involved.     

Poly(methyl acrylate)/poly(hydroxyethyl acrylate) sequential interpenetrating polymer networks. Miscibility and water sorption behavior

Sequential poly(methyl acrylate)/poly(hydroxyethyl acrylate) interpenetrating polymer networks with different poly(hydroxyethyl acrylate) contents were prepared by free radical polymerization of hydroxyethyl acrylate inside the previously polymerized poly(methyl acrylate) network. Differential scanning calorimetry on dry samples shows that the interpenetrating polymer networks exhibit phase separation, and no differences are found between the glass transition temperatures of the two phases present in the interpenetrating polymer network and those of the pure components. Thermally stimulated depolarization current experiments were used to study the influence of water sorption on the mobility of the different molecular groups in the poly(hydroxyethyl acrylate) phase of the interpenetrating polymer network. Isothermal water sorption of the interpenetrating polymer networks and pure poly(methyl acrylate) and poly(hydroxyethyl acrylate) networks is analyzed with different theories to compare the behavior of the poly(hydroxyethyl acrylate) phase in the interpenetrating polymer networks with that of the pure poly(hydroxyethyl acrylate) network. Diffusion coefficients of water in the interpenetrating polymer networks are obtained by means of dynamic sorption experiments. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1587–1599, 1999     

The effect of polymer side chains on vapor sorption in polyacrylate and polymethacrylate solutions

The segment fraction Ψ₁ activity coefficients, a₁/Ψ₁, of solvents have been determined by the piezoelectric sorption method for 0.1 ≤ Ψ₁ ≤ 0.5 in binary solutions of chlorinated methanes [carbon tetrachloride (CCl₄), chloroform (CHCl₃), and dichloromethane (CH₂Cl₂)] with aromatic hydrocarbons (benzene and toluene) in poly(methyl methacrylate), poly(methyl acrylate), poly(ethyl methacrylate), and poly(n-butyl acrylate) at 23.5°C. The present results for toluene in PMMA agree with previously published values obtained by gas-liquid chromatography. For CCl₄ and the aromatic hydrocarbons, the polymer–solvent interaction parameter χ is positive and constant, while for the polar solvents (CHCl₃ and CH₂Cl₂), χ is negative and increases with increasing Ψ₁. The effect of the polymer side chains on vapor sorption in nonpolar and polar solvent systems is discussed in terms of the χ parameter.     

Pure hydrocarbon sorption properties of poly(1-trimethylsilyl-1-propyne) (PTMSP), poly(1-phenyl-1-propyne) (PPP), and PTMSP/PPP blends

Propane and n-butane sorption in blends of poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(1-phenyl-1-propyne) (PPP) have been determined. Solubilities of propane and n-butane increased as the PTMSP content in the blends increased. This result is consistent with the higher free volume of PTMSP-rich blends and the better thermodynamic compatibility between PTMSP and these hydrocarbons. Propane and n-butane sorption isotherms were well described by the dual-mode model for sorption in glassy polymers. PTMSP/PPP blends are strongly phase-separated, heterogeneous materials. A noninteracting domain model developed for sorption in phase-separated glassy polymer blends suggests that sorption in the Henry's law regions (i.e., the equilibrium, dense phase of the blends) is consistent with the model. However, Langmuir capacity parameters in the blends are lower than predicted from the domain model, suggesting that the amount of nonequilibrium excess free volume associated with the Langmuir sites depends on blend composition. © 1996 John Wiley & Sons, Inc.     

超支化聚负离子/超支化聚正离子自组装膜的制备及反应

自1991年以来,静电吸附自组装已发展成为制备具有特定纳米微结构聚电介质多层超薄膜的有效技术。近年来,由于树枝状聚合物和超支化聚合物独特的物理化学性质,文献中已将它们与线性聚电解质一起用于静电吸附自组装过程,但完全基于超支化聚合物分子间的自组装过程还鲜见报道,超支化聚合物所具有的大量末端和内部（如叔胺基）官能团,不仅可以用于调节自组装行为及组装膜的表面形貌,     

Effect of molecular association on solubility,diffusion, and permeability in polymeric membranes

The filling‐type membrane is composed of grafted polymer and solvent‐resistant substrate; the calculation of solubility, diffusivity and swelling‐suppression effect by the substrate permits the prediction of solvent permeability. As noted in our previous article, the use of this approach, called membrane design, resulted in accurate prediction of the permeability of aromatic compounds. In this study, the influence of hydrogen bonding on solubility and diffusivity is investigated both theoretically and experimentally. The solubility of chloroform and dichloromethane in poly(acrylate)s increases, and their diffusivity decreases, compared with that estimated without considering the hydrogen‐bonding effect. Solubilities predicted by the lattice‐fluid hydrogen‐bonding (LFHB) model show good agreement with the results of vapor sorption. Comparison of diffusion coefficients measured by vapor permeation with those predicted from free volume theory reveals that the decrease of solvent diffusion coefficient is approximately proportional to the fraction of associated molecules. Fluxes of chloroform and dichloromethane were measured by vapor permeation experiments through filling‐type acrylate membranes, and predictions agree well with experiments. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 171–181, 2000     

Thermodynamics of water sorption in acrylic homonetworks and IPNs

The equilibrium thermodynamic properties of poly(hydroxyethyl acrylate) and poly(ethyl acrylate)-i-poly(hydroxyethyl acrylate) hydrogels are investigated starting from the water sorption isotherms of the systems. Partial enthalpy and entropy of the sorbed water in the gel differ markedly from the values of pure water at the lowest water contents, and tend to those of liquid water as saturation is approached. The residual mixing free energy is calculated, as a means of assessing the intensity of the water-polymer interaction. Its small positive magnitude shows that water-polymer hydrogen bonds are labile compared to water-water and polymer-polymer hydrogen bonds, and thus the stability of the gel state is still mainly due to the combinatorial entropic contribution to the mixing free energy. An equation correctly describing the sorption isotherms, when combined with the thermodynamic equations, can deliver the true water-polymer interaction parameter and its dependence on the polymer volume fraction in the gel.     

Interval kinetic gravimetric sorption of acetone in random copolymers of poly(ethylene terephthalate) and poly(ethylene 2,6-naphthalate)

Interval sorption kinetics of acetone in solvent cast films of random poly(ethylene terephthalate)-co-(ethylene 2,6-naphthalate) (PET-co-PEN) are reported at 35°C and at acetone pressures ranging from 0 to 7.3 cm Hg. Polymer composition is varied systematically from 0% to 50% poly(ethylene 2,6-naphthalate). Equilibrium sorption is well described by the dual-mode sorption model. Interval sorption kinetics are described using a two-stage model that incorporates both Fickian diffusion and protracted polymer structural relaxation. The incorporation of low levels of PEN into PET significantly reduces the excess free volume associated with the glassy state and, for these interval acetone sorption experiments in ∼ 5 μm-thick films, decreases the fraction of acetone uptake controlled by penetrant-induced polymer structural relaxation. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2973–2984, 1999     

Mechanical activation of catalysts for C-C bond forming and anionic polymerization reactions from a single macromolecular reagent

Coupling of pyridine-capped poly(methyl acrylate)s, PyP(M) (where M corresponds to the number average molecular weight in kDa), to the SCS-cyclometalated dipalladium complex [(1)(CH(3)CN)(2)] afforded organometallic polymers [(1)(PyP(M))(2)] with a concomitant doubling in molecular weight. Ultrasonication of solutions containing [(1)(PyP(M))(2)] effected the mechanical scission of a palladium-pyridine bond, where the liberated PyP(M) was trapped with excess HBF(4) as the corresponding pyridinium salt, harnessed to effect the stoichiometric deprotonation of a colorimetric indicator, or used to catalyze the anionic polymerization of α-trifluoromethyl-2,2,2-trifluoroethyl acrylate. The mechanically induced chain scission also unmasked a catalytically active palladium species which was used to facilitate carbon-carbon bond formation between benzyl cyanide and N-tosyl imines. Spectroscopic and macromolecular analyses as well as a series of control experiments demonstrated that the aforementioned structural changes were derived from mechanical forces that originated from ultrasound-induced dissociation of the polymer chains connected to the aforementioned Pd complexes.     

Pd(OAc)2-catalyzed oxidative coupling reaction of benzenes with olefins in the presence of molybdovanadophosphoric acid under atmospheric dioxygen and air

The direct oxidative coupling reaction of benzenes with alkenes bearing an electron-withdrawing group was successfully achieved by the use of Pd(OAc)(2)/molybdovanadophosphoric acid (HPMoV) as the key catalyst under O(2) or air atmosphere. Thus, the reaction of benzene with ethyl acrylate under air (1 atm) assisted by Pd(OAc)(2)/HPMoV afforded ethyl cinnamate as a major product in satisfactory yield (74%). This catalytic system could be extended to the coupling reactions between various substituted benzenes and alkenes through the direct aromatic C-H bond activation. In the reaction of benzene with ethyl acrylate under O(2) (1 atm), the best turn-over number (TON) of Pd(OAc)(2) reached was 121. This reaction provides a green route to cinnamate derivatives, which are important precursors of a variety of pharmaceuticals.