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本文研究了聚甲基丙烯酸三乙基锡酯(PTETM)在二十五种溶剂中的溶解性能。测定了PTETM试样在不同溶剂中的特性粘数,估算了PTETM的三维溶度参数为:δ=18.8(J/cm~3)~(1/2);δ_d=16.8(J/cm~3)~(1/2);δ_p=6.28(J/cm~3)~(1/2);δ_h=5.73(J/cm~3)~(1/2)。并就聚合物中锡原子上的取代基对其溶解性能的影响进行了讨论。作者还订定了PTETM在四氢呋喃溶液中,25℃时的MHS方程为[η]=2.55×10~(-3)M_w~(0.691);在甲苯溶液中,30℃时的MHS方程为[η]=2.79×10~(-3)M_w~(0.662)。利用Burchard-Stockmayer-Fixman关系,由四氢呋喃体系(25℃)和甲苯体系(30℃)所求得的Flory特征比C_∞=9.4。 相似文献
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Betty Wong Zhiyi Zhang Y. Paul Handa 《Journal of Polymer Science.Polymer Physics》1998,36(12):2025-2032
An in situ gravimetric technique, employing an electrobalance, is described for determining the solubility and diffusivity of gases in polymers over extended ranges of temperature and pressure. Solubilities of CO2 in polystyrene at 35°C were measured as a test case; the results are in excellent agreement with the literature values determined by the pressure decay method. Solubility and diffusivity results are also reported for PVC-CO2 at 35°C and for PS-1,1,1,2-tetrafluoroethane at 30, 90, and 120°C. A comparison with other studies shows the in situ method to be more efficient and precise than the ones based on weighing the gas-saturated polymer under ambient conditions. The kinetics of gas sorption were analyzed in terms of two data reduction techniques to derive diffusion coefficients. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2025–2032, 1998 相似文献
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J. Lonard 《Journal of Polymer Science.Polymer Physics》1993,31(11):1495-1502
Expressions for the entropy and free energy of mixing a solvent with a mixture of linear and cyclic polymer molecules are derived. The entropy of mixing is deduced from the number of ways of arranging on a honeycomb lattice a mixture of totally flexible molecules made up of NR rings and NC chains. An equation is obtained through the combination of two independent expressions for the number of ways of arranging rings and chains. The free energy of mixing is deduced from the entropy and the enthalpy of mixing, using two distinct interaction parameters for ring and for chain molecules. The chemical potentials for solvent, ring polymer, and linear polymer are derived from the free energy of mixing. These quantities are found to be functions of the mole fraction of rings in the polymer mixture. © 1993 John Wiley & Sons, Inc. 相似文献
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Ling Hong Yanjun Cui Xinling Wang Xiaozhen Tang 《Journal of polymer science. Part A, Polymer chemistry》2002,40(3):344-350
A new method for the synthesis of hyperbranched polymers involving the use of ABx macromonomers containing linear units have been investigated. Two types of novel hyperbranched polyurethanes have been synthesized by a one‐pot approach. The structures of monomers and polymers were characterized by elemental analysis, 1H NMR, 13C NMR, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The hyperbranched polymers have been proven to be extremely soluble in a wide range of solvents. Polymer electrolytes were prepared with hyperbranched polymer, linear polymer as the host, and lithium perchlorate (LiClO4) as the ion source. Analysis of the isotherm conductivity dependence of the ion concentration indicated that these hyperbranched polymers could function as a “solvent” for the lithium salt. The conductivity increased with the increasing concentration of hyperbranched polymers in the host polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 344–350, 2002 相似文献
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Panzheng Zhou Kevin L. Sánchez-Rivera Prof. George W. Huber Prof. Reid C. Van Lehn 《ChemSusChem》2021,14(19):4307-4316
One promising approach to recycle multicomponent plastic waste (e. g., multilayer plastic films) is selective dissolution. Selective dissolution is a solvent-mediated process in which differences in polymer solubility in a carefully chosen solvent system are exploited to recover a target polymer. Here, a computational approach was developed that rapidly predicts temperature-dependent polymer solubilities to guide the design of solvent systems for solvent-mediated polymer recycling. Polymer conformations were obtained from molecular dynamics simulations by modeling the polymer as a short oligomer and then used as input to the conductor-like screening model for real solvents (COSMO-RS) for solubility predictions. Using polyethylene (PE) and ethylene vinyl alcohol (EVOH) as representative polymers, the effect of simulation parameters was systematically studied, and predicted solubilities were found to be in good agreement with experimental measurements. The applicability of the approach was demonstrated by identifying selective solvents for PE and EVOH dissolution from a library of 524 solvents. 相似文献
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E. Bianchino S. Piotto F. Mavelli M. L. Curri M. Striccoli 《Macromolecular Symposia》2009,286(1):156-163
Dissipative Particle Dynamics has been used to investigate the different morphology of polymer nanocomposites. Such a study was addressed to the definition of a suitable tool for understanding the distribution of oleic acid (OA) capped nanoparticles embedded into poly-methylmethacrylate (PMMA) matrix for the formation of nanocomposite materials. In particular, simulations of PMMA/OA mixtures at different composition have exhibited the self-assembly of amphiphiles to form separated nanosized domains with different morphologies going from spheres, to tubules up to the formation of continuous planar sheets as the OA composition increases. On the other hand, simulations carried out on nanocomposite systems have shown that NPs do not perturb the observed phase behaviour of PMMA/OA mixtures. In fact, at low OA compositions nanoparticles are confined in the spherical lipid domains to form NP clusters, while at high OA composition NPs appear homogeneously distributed in the continuous lipid domain. 相似文献
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Jun Yano 《Journal of polymer science. Part A, Polymer chemistry》1995,33(14):2435-2441
A conducting polymer, poly(o-phenylenediamine) (PoPD), has been obtained as stable film onto an electrode surface by the electropolymerization of o-phenylenediamine in 0.1 mol dm?3 H2SO4. The film thickness did not exceed 0.85 μm because of its low electrical con-ductivity. The virgin “doped” polymer film was soluble in dimethylsulfoxide N, N-dimeth-ylformamide, acetone, and tetrahydrofuran without any pretreatment. The highest solubility obtained was 17 g dm?3 in dimethylsufoxide. A cast film of PoPD on a substrate was prepared from its dimethylsulfoxide solution. The mean molecular weight of PoPD was found to be 11,000 with the gel permeation chromatography. The STM observation exhibited that the cast film was considerably uniform compared to the electrodeposited film. The cyclic voltammogram of such film showed a reversible redox property accompanied with excellent electrochromism between transparent yellow and brown. It was suggested from the 1H-FTNMR and FTIR spectra and the elemental analysis that the polymeric backbone has 1, 4-substituted benezenoid-quinoid structure. © 1995 John Wiley & Sons, Inc. 相似文献
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两性纤维素接枝共聚物CGD的研究：Ⅱ水溶液的性质 总被引：1，自引：0，他引：1
用浊度法研究了一系列不同结构特征的羧甲基纤维素接枝甲基丙烯酸二甲胺基乙酯两性共聚物（ＣＧＤ）的溶解性及其组成和等电点的关系;用粘度法研究了ＣＧＤ水溶液的流体力学性质,考察了聚合物浓度,温度,外加无机盐和ｐＨ对溶液流体力学性质的影响。研究发现ＣＧＤ具有明显的等电点,且与组成有关,即随着阳离子链节含量的增加,等电点移向高ｐＨ 相似文献
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Junqiang Guo Liwei Lin Yuping Wang Wang Zhang Guowang Diao Yuanzhe Piao 《Molecules (Basel, Switzerland)》2022,27(20)
Diphenylguanidine (DPG) is a widely used secondary accelerator for the vulcanization of natural rubber (NR) latex. However, its low water solubility and high toxicity limit its use in high-end NR products. In this study, a water-soluble inclusion complex of DPG and a β-cyclodextrin polymer (β-CDP), termed DPG-β-CDP, was prepared through supramolecular interactions and characterized using Fourier-transform infrared spectroscopy, 1H NMR, scanning electron microscopy, and UV-vis spectroscopy techniques. In comparison with that of DPG, the water solubility of DPG-β-CDP was greatly enhanced because of the water-soluble host molecule. The molar ratio of DPG to the CD unit in β-CDP was determined to be 1:1. At 25 °C, the binding constant of DPG-β-CDP was found to be 9.2 × 105 L/mol by UV-vis spectroscopy. The proposed method for forming inclusion complexes with high potential for use as water-soluble vulcanization accelerators is promising. 相似文献
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AbstractHydrophobic associating polyacrylamide (PDH) was prepared via aqueous dispersion polymerization in the presence of ammonium sulfate. In order to dissolve the polymer at high salt solution concentration, a hydrophobic precursor monomer with two cationic heads was synthesized. Upon polymerization, spherical PDH polymer particles were obtained with an average size of about 9.1?µm. The PDH was fully dispersed in water in twenty seconds, leading to a transparent gel. PDH demonstrated superior properties compared to the partially hydrolyzed polyacrylamide, for instance, regarding salt tolerance and shear resistance. Addition of a small amount of an anionic surfactant significantly affected the PDH dispersion viscosity due to the formation of mixed micelles. The viscosity slightly decreased after strong shearing (>500?s?1), showing excellent shear resistance. These features indicate that the synthesized PDH offers a great potential for application in hydraulic fracturing and enhanced oil recovery. 相似文献
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J. Szeman E. Fenyvesi J. Szejtli H. Ueda Y. Machida T. Nagai 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(4):427-431
The complex forming ability of a water-soluble -cyclodextrin epichlorohydrin, polymer (CDPS) and its different molecular weight fractions was studied and compared with the complexing properties of -cyclodextrin (CD) and dimethyl-CD (DM-CD). CDPS was separated into two main fractions. CDPS and its fractions formed well soluble inclusion compounds with the studied drugs. The low molecular weight fraction formed rather stable complexes with small guest molecules, the high molecular weight fraction was found to be more efficient in binding larger substrates. Structural studies of furosemide-CD complexes were attempted by NMR spectroscopy.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K., 20–25 July 1986. 相似文献
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采用固定体积可视观察法测量装置,在50～80℃温度范围内测定了CO2与叔丁醇于不同压力下的平衡数据.通过对高压状态下CO2在液相中的溶解度和叔丁醇在气相中的溶解度模型的研究,对亨利定律和Chrastil半经验溶解度方程进行了改进,提出了分别适合于高压状态下CO2与叔丁醇二元体系的相互溶解度模型.其中CO2在液相中的溶解度可用三次多项式模型关联,其形式为:Pco2=A+B1·xco2+B2·x2co2+b3·x3co2.叔丁醇在O2中的溶解度可用改进的Chrastil半经验溶解度方程进行模拟,其形式为C=ρk·exp(a/T)+b+c·ρm.结果表明,提出的气相溶解度方程和液相溶解度方程与实验数据有着较高的拟合相关系数和精度. 相似文献
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Aylin Şakar-Deliormanlı Erdal Çelik Mehmet Polat 《Journal of Dispersion Science and Technology》2013,34(5):704-711
In this study, solubility behavior of lead magnesium niobate (PMN) powders in water was investigated in the presence of pure polyacrylic acid and polyacrylic acid/polyethylene oxide comb polymers. Experiments were performed by measuring the solubility of PMN in terms of the concentration of Pb+2 and Mg+2 ions in supernatant as a function of pH and dispersing agent dosage. The concentrations of the metal ions in supernatant were found to be affected by the dispersant concentration, stirring time and the suspension pH. Results revealed that both dispersing agents enhance the cation dissolution from PMN surface at pH 9 due to weak (reversible) adsorption and complexation of Pb+2 and Mg+2 by carboxylate groups. On the other hand, under acidic conditions cation dissolution from PMN is inhibited and this was attributed to the strong adsorption of dispersing agents onto the powder surface and formation of a dense polymer layer. 相似文献
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Jesper Neergaard Ole Hassager Peter Szabo 《Journal of Polymer Science.Polymer Physics》2003,41(7):701-706
We propose a model for a priori prediction of the solubility of gases in flexible polymers. The model is based on the concept of ideal solubility of gases in liquids. According to this concept, the mole fraction of gases in liquids is given by Raoult's law with the total pressure and the vapor pressure of the gas, where the latter may have to be extrapolated. However, instead of considering each polymer molecule as a rigid structure, we estimate the effective number of degrees of freedom from an equivalent freely jointed bead‐rod model for the flexible polymer. In this model, we associate the length of the rods with the molecular weight corresponding to a Kuhn step. The model provides a tool for crude estimation of the gas solubility on the basis of only the monomer unit of the polymer and properties of the gas. A comparison with the solubility data for several gases in poly(dimethylsiloxane) reveals agreement between the data and the model predictions within a factor of 7 and that better model results are achieved for temperatures below the critical temperature of the gas. The model predicts a decreasing solubility with increasing temperature (because of the increasing vapor pressure) and that smaller gas molecules exhibit a lower solubility than larger ones (e.g., CH4 has a smaller solubility than CO2), which agrees with the experimental data. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 701–706, 2003 相似文献
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Zhuanping Wang Prof. Jixing Yang Zifeng Chen Prof. Long Ye Prof. Yunhua Xu 《ChemSusChem》2021,14(20):4573-4582
In-situ electro-polymerization of redox-active monomers has been proved to be a novel and facile strategy to prepare polymer electrodes with superior electrochemical performance. The monomer molecular structure would have a profound impact on electro-polymerization behavior and thus electrochemical performance. However, this impact is poorly understood and has barely been investigated yet. Herein, three carbazole-based monomers, 9-phenylcarbazole (CB), 1,4-bis(carbazol-9-yl)benzene (DCB), and 2,6-bis(carbazol-9-yl)naphthalene (DCN), were applied to study the above issue systematically and achieve excellent long cycle performance. The monomers were rationally designed with different polymerizable sites and solubilities. It was found that a monomer with increased polymerizable sites and decreased solubility brought about enhanced electrochemical performance. This is because poor solubility could enhance utilization of the monomer for polymerization and more polymerizable sites could lead to a stable crosslinked polymer network after electro-polymerization. DCN with four polymerizable sites and the poorest solubility displayed the best electrochemical performance, which showed stable cycling up to 5000 cycles with high capacity retention of 76.2 % (among the best cycle in the literature). Our work for the first time reveals the relationship between monomer structure and in-situ electro-polymerization behavior. This work could shed light on the structure design/optimization of monomers for high-performance polymer electrodes prepared through in-situ electro-polymerization. 相似文献
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文献中未见MCl-HCl-H2O(M=Li、Na、K、Rb、Cs)三元体系25℃时在HCl全浓度范围内溶解度预测的报道。本文报道应用Pitzer的离子相互作用模型,系统地对0.1～16.0 mol·kg-1浓度范围内HCl的活度系数和渗透系数值进行最小二乘法拟合,得到一套优于文献上报道的作用参数。用这一套参数和本文报道中五个三元体系得到的θmn和φmnx,对溶解度预测获得满意结果。本方法可以推广到其它任何温度时、甚至相关四元和五元体系的溶解度预测,可以减少繁琐的实验测定,并对于利用HCl从盐卤中盐析分离LiCl、RbCl和CsCl的相化学工艺计算具有实际意义。 相似文献