水溶性疏水缔合型聚(丙烯酰胺-丙烯酸十六酯)溶液性质的研究

采用沉淀聚合法制备水溶性的丙烯酰胺－丙烯酸十六疏水缔合型共聚物,研究了共聚物水溶液的性质及其影响因素。随着疏水基团含量增加,共聚物在纯水中及NaCl溶液中的特性粘数[η]均减小,疏水基团临界缔合浓度降低。共聚物溶液浓度高于监界缔合浓度时,溶液表现粘度急剧增加,表明溶液中分子间缔合大量形成。     

疏水基改性聚丙烯酰胺的合成及溶液性质

利用自由基胶束聚合法,由丙烯酰胺和甲基丙烯酸十八酯共聚合成了疏水缔合型水溶性聚合物.通过红外光谱表征了共聚物的结构,考察了共聚物浓度、盐浓度、剪切速率以及温度对共聚物溶液性能的影响.试验结果表明,聚合物质量分数大于临界缔合浓度(2%)时,溶液的粘度急剧增大;疏水缔合聚合物溶液的表观粘度随着溶液中NaCl质量分数的增加而增大.     

(丙烯酰胺-丙烯酸十六酯)共聚物的合成及其增稠性能研究

采用沉淀聚合法合成丙烯酰胺 -丙烯酸十六酯共聚物。重点讨论了合成条件如单体配比、引发剂用量、温度等对共聚反应的影响以及共聚物对苯丙乳胶的增稠性能的影响。并用DMTA和凯达尔定氮法表征了共聚物组成 ,结果表明 :所合成的共聚物可以作为疏水缔合型增稠剂使用     

AM/AA/DMDAAC/OAM疏水缔合的两性共聚物的合成及性能研究

以十八醇为原料,制备长链疏水单体N-十八烷基丙烯酰胺(OAM)。以丙烯酰胺(AM)、丙烯酸(AA)、二甲基二烯丙基氯化铵(DMDAAC)、N-十八烷基丙烯酰胺(OAM)为单体,通过胶束聚合法合成了水溶性疏水缔合两性四元共聚物。利用FT-IR、1HNMR、DTA-TG对聚合物的结构和热稳定性进行分析,考察了疏水基团摩尔分数、聚合物浓度对聚合物溶液表观粘度、储能模量、耗能模量等流变性能的影响,并对四元共聚物溶液的性能进行评价。结果表明,疏水两性共聚物具有很好的耐温、抗盐、耐剪切等优异性能。     

PABA疏水缔合水溶性共聚物溶液的合成与性能研究

本文根据高分子的分子设计原理，合成了带苯基的疏水单体N－苯基对正丁基丙烯酰胺（BBAM）。采用自由基胶束共聚的方法制备了水溶性丙烯胺／N－苯基对正丁基丙烯酰胺（BBAM）疏水缔合型共聚物（PABA）。研究了共聚物溶液的性能及影响因素。结果表明，随共聚物溶液浓度的增加，在临界缔合浓度以上，分子间缔合大量形成，水溶液表现粘度迅速增加，表现出明显的疏水缔合行为，与HPAM相比有优异的抗盐性。     

P(AM-NVP-DMDA)疏水缔合水溶性共聚物的研究

采用自由基水溶液共聚合法制备了Ｐ（ＡＭ－ＮＶＰ－ＤＭＤＡ）疏水缔合水溶性共聚物。对共聚物的溶液性能进行了研究,包括盐效应、粘温关系、流变性能、热稳定性、与碱、表面活性剂的相互作用、稀溶液性质等。共聚物分子中由于引入了较多的疏水基团而具有较强的疏水缔合效应,在聚合物浓度较低时具有较高粘度。ＮＶＰ结构单元的引入可适当提高共聚物溶液的热稳定性。对共聚物溶液的电镜分析结果表明,在其水溶液中存在着微相分离结构,它对共聚物溶液的增粘起着重要作用。     

疏水修饰聚丙烯酸共聚物在水溶液中的缔合作用

丙烯酸类共聚物具有良好的增稠,分散,成膜和絮凝等性能,因而在涂料,皮革,油漆,颜料及油田开发等领域具有广泛的用途^[1],但当体系中可溶性盐类含量高时,该类水溶性大分子的使用效果不降,而疏水修饰共聚物可克服原聚合物对高价金属离子敏感的缺陷^[2],疏水修饰共聚物在水溶液中可缔合成胶束状团簇（MLCs),造成大分子的流体动力学尺寸增大,从而使溶液粘度增大,MLCs的疏水微区可增溶油类物质,因此疏水修饰大分子可作为含高价离子浓度体系的流度控制剂^[3],本文利用荧光探针技术^[4,6]探讨了丙烯酸丁酯－丙烯酸－甲基丙烯酸共聚物在纯水和盐水溶液中的缔合作用。     

丙烯酰胺与丙烯酸十四酯共聚物的合成及性能研究

利用过氧化苯甲酰为引发剂探讨了丙烯酰胺（ＡＭ）和丙烯酸十四酯（ＴＡ）的自由基共聚合。重点讨论了合成条件如引发剂用量，单体配比、溶剂、温度等对共聚反应及共聚物对苯丙乳胶增稠性能的影响。并用ＩＲ和凯达定氮法表征了共聚物的组成，实验结果表明，ＡＭｔ ＴＡ进行沉淀聚合所得到的共物分子量足够大，可以作为疏水缔合型稠剂使用。     

孪尾疏水缔合丙烯酰胺/丙烯酸钠/N,N-二辛基丙烯酰胺共聚物的合成与性能

孪尾疏水缔合丙烯酰胺/丙烯酸钠/N; N-二辛基丙烯酰胺共聚物的合成与性能;孪尾;胶束聚合;水溶性聚合物;疏水缔合;合成;粘度     

疏水缔合聚丙烯酰胺与双子表面活性剂的相互作用

制备了一种脂肪酸酯双磺酸盐型双子表面活性剂, 利用粘度法、界面张力法和原子力显微镜研究了疏水缔合聚丙烯酰胺与双子表面活性剂在溶液中的相互作用. 实验结果表明: 疏水缔合聚丙烯酰胺在溶液中能够通过自组装形成疏水微区并发展成网络结构, 疏水微区与表面活性剂在溶液中能形成混合胶束; 当一定量的表面活性剂加入时, 对疏水缔合聚丙烯酰胺的自组装起促进作用, 而过多双子表面活性剂的加入又会对聚合物分子的自组装起抑制作用, 从而显著影响疏水缔合聚丙烯酰胺的溶液性质, 随着表面活性剂浓度的增加, 聚合物溶液粘度先增加、再降低; 同时, 疏水缔合聚丙烯酰胺对双子表面活性剂的界面性能也有较大影响, 聚合物的加入使双子表面活性剂降低油/水界面张力的能力下降, 油/水界面张力达到平衡所需时间延长.     

高分子体系的溶剂吸附平衡预测

通过考察芳香族溶剂和聚丙烯酸酯混合过程内聚能和混合体积的变化,阐明剩余体积对高分子溶液体系相平衡的影响,在理论上比较UNIFAC-FV和GCLF-EOS模型。使用石英弹簧法测定25℃下苯、甲苯和乙苯在聚丙烯酸甲酯、聚丙烯酸丁酯和聚丙烯酸十二酯中的吸附曲线,分别用以上数学模型对其进行预测,由于GCLF-EOS模型以状态方程式作为基础,能够正确反映高分子溶液中分子间相互作用和剩余体积变化行为,模型预测结果和实验值基本一致。     

Design of antibacterial surfaces by a combination of electrochemistry and controlled radical polymerization

In this paper we report a new method for the electrochemical deposition of a metal/polymer composite layer on a conducting substrate. The electrochemical solution is a mixture of an acrylate (ethyl acrylate, EA; 2-phenyl-2-(2,2,6,6-tetramethylpiperidin-1-yloxy)ethyl acrylate, PTEA; 8-quinolinyl acrylate, 8QA), a metallic salt (silver(I) acetate), and a conducting salt in dimethylformamide. The process has been first studied with EA as the polymer precursor and then extended to PTEA and 8QA, respectively, with the purpose to prepare antibacterial surfaces. The final coating has been characterized by attenuated total reflection Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, environmental scanning electron microscopy, and atomic force microscopy. All the silver-containing coatings were effective against Gram-negative bacteria Escherichia coli. Bacteria Staphylococcus aureus could not adhere to the Ag(0)/polyacrylate films deposited on stainless steel.     

Diffusivity of solvent in a polymer solution—expansive free volume effect

The concentration dependency of the diffusivity of a solvent in a polymer solution is derived on the basis of a free volume theory. Applying a molecular kinetics approach, the Fujita-Doolittle equation is modified. The result of numerical simulation reveals that the diffusivity of solvent in a polymer solution depends largely on both the polymer chain structure and its concentration. The applicability of the analytical expression derived is justified by fitting the experimental data for n-alkyl acetate-(poly-methyl acrylate) polymer solutions in the literature.     

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     

Steric effects and competitive intra‐ and intermolecular host‐guest complexation between beta‐cyclodextrin and adamantyl substituted poly(acrylate)s in water: A 1H NMR,rheological and preparative study

A ¹H NMR and rheological study of host‐guest complexation interactions between three β‐cyclodextrin and three adamantyl substituted poly(acrylate)s, and also between them and adamantan‐1‐carboxylate and native β‐cyclodextrin, respectively, is reported. A close correllation between molecular level interactions and macroscopic characteristics of polymer networks in aqueous solution exists. It is found that intra‐ and intermolecular host‐guest complexation between the host β‐cyclodextrin and guest adamantyl substituents and the length of the aliphatic tether between them and the poly(acrylate) backbone have important roles. Dominantly, steric effects and competitive intra‐ and intermolecular host‐guest complexation are found to control poly(acrylate) isomeric interstrand linkage in polymer network formation. The preparations of five new 3% randomly substituted poly(acrylate)s are reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1818–1825, 2010     

Preparation of biodegradable and thermoresponsive enzyme–polymer conjugates with controllable bioactivity via RAFT polymerization

The preparation of biodegradable and thermoresponsive enzyme–polymer bioconjugates with controllable enzymatic activity via reversible addition−fragmentation chain transfer (RAFT) polymerization and amidation conjugation reaction is presented. A new 2-mercaptothiazoline ester functionalized RAFT agent with intra-disulfide linkage was synthesized and used as chain transfer agent (CTA) to generate a biocompatible homopolymer, poly(ethyleneglycol) acrylate (polyPEG-A) and a thermoresponsive copolymer of poly(ethyleneglycol) acrylate with di(ethyleneglycol)ethyl ether acrylate [poly(PEG-A-co-DEG-A)]. These biodegradable and thermoresponsive polymers were then conjugated to the surface of glucose oxidase (GOx) under mild condition to afford the biodegradable and thermoresponsive enzyme–polymer conjugates. Cleavage of the polymer chains from the GOx surface obviously recovered the enzymatic activity. The thermoresponsive test of GOx-poly(PEG-A-co-DEG-A) revealed that the bioconjugate exhibited regular enzymatic activity fluctuation upon the temperature change below or above the lower critical solution temperature (LCST). The as-prepared enzyme–polymer conjugates were also characterized using ¹H NMR, UV–vis spectroscopy, polyacrylamide gel electrophoresis (PAGE) and biocatalytic activity tests. These smart enzyme–polymer conjugates would envision promising applications in biotechnology and biomedicine.     

Self-discharge characteristics of an electric double-layer capacitor with polymer hydrogel electrolyte

An electric double-layer capacitor (EDLC) was assembled with the polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) (PAAK) and KOH aqueous solution, and the self-discharge characteristics were investigated. The EDLC cell with the polymer hydrogel electrolyte showed lower voltage decay on open circuit than that with a KOH aqueous solution. Moreover, it was found that the leakage current of the EDLC cell was markedly suppressed by using the polymer hydrogel electrolyte. The suppression was enhanced with increasing PAAK content in the electrolyte. These results strongly suggest that the PAAK plays an important role in the suppression of self-discharge.     

Molecularly imprinted polymers with assistant recognition polymer chains for bovine serum albumin

A new protein molecularly imprinted polymer (MIP) was prepared with grafting polyvinyl alcohol as assistant recognition polymer chains (ARPCs). The ARPCs and acrylamide monomers were interpenetrated and then polymerized on the surface of macroporous acrylate adsorbent spheres. The template BSA was removed by treatment with 2.00 mol L-1 potassium chloride (KCl) solution and the adsorbed proteins were detected with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). 0.150, 0.500, and 2.00 mo...     

The shape of protein–polymer conjugates in dilute solution

Protein–polymer conjugation can significantly affect many different aspects of protein behavior, ranging from their solution properties to their ability to form solution and bulk nanostructured materials. An underlying fundamental question is how the molecular design affects the shape of the conjugate and, consequently, its properties. This work measures the molecular configuration of model protein–polymer conjugates in dilute solution using small-angle neutron scattering (SANS) and uses quantitative model fitting to understand the shape of the molecules. Form factor measurements of four model bioconjugates of the red fluorescent protein mCherry and the polymers poly(N-isopropylacrylamide), poly(hydroxypropyl acrylate), poly(oligoethylene glycol acrylate), and poly(ethylene glycol) show that these protein–polymer conjugates are well described by a recently developed scattering function for colloid–polymer conjugates that explicitly incorporates excluded volume interactions in the polymer configuration. In the regime where the protein does not exhibit strong interactions with the polymer, modeling the protein–polymer interactions using a purely repulsive Weeks–Chandler–Andersen potential also leads to a coarse-grained depiction of the conjugate that agrees well with its scattering behavior. The coarse-grained model can additionally be used for systems with varying protein–polymer interactions, ranging from purely repulsive to strongly attractive, which may be useful for conjugates with strong electrostatic or hydrophobic attractive interactions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 292–302     

Cation binding properties of poly(crown ethers) with photodimerizable groups

Polymers that have crown ether groups as cation binding sites and cinnamic acid ester groups as photodimerizable groups were prepared by the cationic polymerizations of 2-vinyloxyethyl 4′-(2,3-benzo-1,4,7,10,13-pentaoxa-2-cyclopentadecene)acrylate and 2-vinyloxyethyl 4′-(2,3-benzo-1,4,7,10,13,16-hexaoxa-2-cyclooctadecene)acrylate. When irradiated with ultraviolet (UV) light the cinnamic acid ester groups of the polymers caused dimerization in dilute solution without the formation of insoluble materials. The irradiation was carried out in a dioxane solution and an aqueous solution in the presence and absence of salts. The effect of phototransformation of polymers on the cation binding properties was investigated by a method of picrate salts extraction. The binding ability of the phototransformed polymers for alkali and alkaline earth metal cations was higher than that of the native polymer. Furthermore the cation binding ability of the phototransformed polymers was less sensitive to temperature than that of the native polymer. The effect of the degree of photodimerization of the polymers and the concentration of KCl that exists during irradiation on the cation binding ability was also investigated.