表面活性含氟单体-丙烯酰胺共聚物溶液性质研究

以异佛尔酮二异氰酸酯(IPDI)、十二氟庚醇(FOH)、烯丙基聚乙二醇(APEG)合成的表面活性含氟单体(FSM)与丙烯酰胺通过水溶液聚合,制备出含氟疏水缔合聚丙烯酰胺(FPAM).用表面张力法研究了FSM的胶束化,用流变仪、动态激光光散射(DLS)和原子力显微镜(AFM)表征了FPAM溶液的流变性能、缔合结构尺寸和形态.结果表明,FSM在25℃下CMC为1.28 g.L-1,表面张力为26.77 mN.m-1.FPAM溶液属于假塑性体系,临界缔合浓度为0.660%,具有一定的耐盐性.DLS和AFM表明,在低于临界缔合浓度时FPAM溶液仍能产生大量的缔合结构,FPAM分子具有很强的疏水缔合性.     

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.     

改性聚丙烯酰胺水溶液的疏水缔合性质

合成了一种疏水缔合水溶性聚丙烯酰胺共聚物,使用荧光光谱法并结合紫外及流变性实验,对制备的疏水缔合水溶性聚丙烯酰胺共聚物在水溶液中形成疏水微区、超分子聚集体及空间网络结构进行了研究,并用扫描电子显微镜证实了溶液中网络结构的存在.     

含氟疏水缔合聚丙烯酰胺的制备及溶液性质研究

以异佛尔酮二异氰酸酯(IPDI)、四氟丙醇(FOH)和烯丙基聚乙二醇(APEG1200)为原料合成了含氟表面活性单体(FSM),并以FSM为疏水单体,在它的胶束溶液中实现了其与丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)的水溶液共聚合,制备出含氟疏水缔合聚丙烯酰胺(FAPAM)。采用流变仪研究了FAPAM水溶液的疏水缔合性能,并考察了盐、剪切率和温度对FAPAM缔合性能的影响。结果表明,FAPAM水溶液的疏水缔合性能受FSM含量的影响,具有一定的耐盐性。FAPAM属于假塑性体系,表现出较强的抗剪切性能。适当升高温度对FAPAM水溶液的疏水缔合有一定的促进作用。     

聚丙烯酰胺水溶液的流变性质

粘性指进现象;聚丙烯酰胺水溶液的流变性质     

疏水改性聚丙烯酰胺溶液的分子模拟

设计了几种不同的非离子型改性聚丙烯酰胺(HM-PAM)和阴离子型改性聚丙烯酰胺(HM-HPAM). 通过分子动力学模拟(MD)方法研究了在聚合物链上加入不同疏水改性单体对提高聚丙烯酰胺耐盐性的影响, 考察了盐浓度对疏水改性聚丙烯酰胺的回旋半径(R_g)、 特性黏数([η])、 径向分布函数(RDF)和均方位移(MSD)的影响以及聚合物的微观结构与特性黏数之间的关系. 研究结果表明, 引入疏水改性单体后, 改性聚丙烯酰胺具有较好的耐盐性. 通过研究非键作用与氢键相互作用可知, 体系中溶质和溶剂间的相互作用及氢键作用越弱, 溶液的特性黏数越大. O-H原子对的RDF结果表明, 聚合物链的伸展与聚合物链及官能团间的相互作用有关. 当RDF峰较弱时, 聚合物链与水的作用越弱, 越有利于聚合物链保持舒展状态, 溶液的特性黏数也就越大. 另外, 从聚合物链的MSD曲线发现, 聚合链的移动性与特性黏数呈负相关.     

水溶性高聚物聚丙烯酰胺的稀溶液性质(Ⅰ)

 本工作利用光散射和粘度方法,使用辐射聚合聚丙烯酰胺(PAAM)的级分样品,研究了在较宽分子量范围(10⁴-10⁷)内PAAM的特性粘数,分子尺寸及第二维利系数对重均分子量的依赖性.从实验上得到了PAAM在0.2mol/lNaCl水溶液中的均方旋转半径与均方末端距之间的关系及高分子-溶剂相互作用参数.     

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。     

阳离子聚丙烯酰胺的制备及其絮凝性能

研究了氧化还原引发剂质量分数、偶氮类引发剂质量分数、阳离子度等因素对所制备的阳离子聚丙烯酰胺特性粘数的影响,探讨了pH值、阳离子聚丙烯酰胺特性粘数、阳离子度、用量等因素对污泥絮凝性能的影响. 较佳的制备条件为:复合引发体系中(NH4 )2 S2 O8 和CH3 NaO3 S·2H2 O总质量分数为0.015 0%、偶氮类引发剂质量分数为0.012 5%、单体质量分数为40%、阳离子度为40%,产物特性粘数为13.1 dL/g. 在污泥pH=6.0、阳离子聚丙烯酰胺特性粘数为11.9 dL/g、阳离子度为40%、用量为0.027%的较佳絮凝条件下,污水的透光率达98.0%,絮凝率达66.0%,脱水率达70.0%.     

疏水缔合聚丙烯酰胺的合成及溶液性能研究

水溶性疏水缔合聚合物是在聚合物亲水主链上引入极少量疏水基团(一般小于2ｍｏｌ%)而形成的一种新型水溶性聚合物[1]。由于这类聚合物具有独特的流变性能,因而备受学术界和工业界关注。目前已作为涂料增稠剂[2]和流变改性剂[3]得到了应用,而通过在部分水解聚丙烯酰胺(ＨＰＡＭ)的亲水主链上引入少量疏水单体而形成的疏水缔合聚丙烯酰胺(ＨＡＰＡＭ)则可望克服ＨＰＡＭ耐温、耐盐性差的缺陷[4]而作为新一代水溶性聚合物材料用于油气开采作业[5,6]。由于亲水单体和疏水单体的不相容性,通常通过在反应溶液中加入表面活性剂使亲水单体和疏水单体…     

疏水化两性离子纤维素接枝共聚物/疏水化聚丙烯酰胺复合溶液的粘性行为

疏水缔合作用;羧甲基纤维素;疏水化两性离子纤维素接枝共聚物/疏水化聚丙烯酰胺复合溶液的粘性行为     

Effects of Ethylene Oxide Spacer Length on solution Properties of Water—Soluble Fluorocarbon—Containing Hydrophobically Associating Poly（Acrylic Acid—co—Rf—PEG Macromonomer）

Poly(acrylic acid)s (PAAs) modified with a series of fluorocarbon group (Rf) end-capped Poly(ethylene glycol) (PEG) macromonomers(number of ethylene oxide unit:1,9,23,45) and corresponding copolymers without fluorocarbon end groups were synthesized.It was found that the effect of the hydrophobic association of fluorocarbon groups on the solution viscosity prevailed over that of the hydrogen bond between grafted PEG and the backbone.Rheological measurement on the aqueous solutions of these poly(acrylic acid-co-Rf-PEG macromonomer) s demonstrated that the best thickening performance was shown when the number of ethylene oxide unit (EO number) was 23.     

Effect of Mineral Salts on Steady Rheological Properties of Nonionic Hydrophobically Modified Polyacrylamide and Its Stress-Relaxation Behavior

A micelle-forming polymerizable surfactant monomer, octylphenol polyoxyethylene acrylate (OP-10-AC), was synthesized, and then OP-10-AC was copolymerized with acrylamide (AM) to form nonionic hydrophobically modified polyacrylamide P(AM/OP-10-AC) through micellar copolymerization. In the absence of surfactants, it was investigated in detail that the effect of mineral salts and temperature on steady rheological properties of P(AM/OP-10-AC) solutions and the effect of concentrations on reduced viscosity of P(AM/OP-10-AC) in a dilute solution. The results indicate that concentrations of the copolymer, mineral salts and temperature had a strong influence on shear viscosity of P(AM/OP-10-AC) solutions, and the trend of reduced viscosity of P(AM/OP-10-AC) solutions was distinctly different from polyacrylamide with increasing concentrations of testing solutions. In addition, it was also investigated that stress-relaxation behavior of an aqueous solution of P(AM/OP-10-AC)/KCl. As a result, a stress-relaxation model of the copolymer solutions was proposed, which can further verify the correctness of the conclusion on stress-relaxation behavior of hydrophobic association hydrogels in the paper reported previously.     

疏水缔合聚丙烯酰胺在盐水中的自组装行为

使用静态光散射、动态光散射以及原子力显微镜(AFM)研究了疏水缔合聚丙烯酰胺(HAPAM)在盐水溶液中的自组装行为.研究了聚合物分子在不同盐浓度中的表观重均分子量(Mw,a),均方根回转半径(),流体力学半径(),第二维里系数(A2)的变化,并根据/的比值得出聚合物分子的聚集形态.实验结果表明:随着盐浓度的增强,聚合物溶液的分子链由舒展变得卷曲.     

Studies on Interaction of Hydrophobically Modified Polyacrylamide of a New Family with Cationic Gemini Surfactant

A new family of hydrophobically modified polyacrylamides (HMPAM) was synthesized via homogeneous copolymerization of acrylamide (AM) and anionic surface-active monomer of acrylamide-type, sodium 2-acrylamido-tetradecane sulfonate (NaAMC₁₄S) in aqueous solution. The copolymers NaAMC₁₄S/AM with microblock structures and with different chain microstructures were obtained by varying the copolymerization factors, such as the feed ratio of NaAMC₁₄S to AM and the amount of added electrolyte NaCl and initiator. The interaction between copolymers NaAMC₁₄S/AM and cationic gemini surfactants, C₁₂C₃C₁₂Br₂ and C₁₂C₆C₁₂Br₂, was studied by using viscosimetry and fluorescent probe technique. The results show this new family of HMPAM, NaAMC₁₄S/AM, has very strong interaction with gemini surfactants, and their aqueous solutions exhibit unique rheological properties.     

Intramolecular Polycomplexes Formed by Dextran-Grafted Polyacrylamide: Effect of the Components Molecular Weight

Graft copolymers of Polyacrylamide-g-Dextran were synthesized using ceric-ion-initiated solution polymerisation technique. It is shown that the macromolecular parameters of these copolymers and their molecular structure strongly depend on the molecular weight of the Dextran part.     

氢键型聚芳醚酮共聚物的合成与表征

氢键型聚芳醚酮共聚物的合成与表征王忠刚，陈天禄，徐纪平（中国科学院长春应用化学研究所长春１３００２２０）关键词氢键，聚芳醚酮，合成，表征高分子链之间的氢键相互作用可以有效地提高聚合物的性能［１，２］．本工作通过共聚反应，在酚酞型聚芳醚酮ＰＥＫ－Ｃ分子...     

Solution Association Characterization of Hydrophobically Associating Polyacrylamide Obtained from Produced Fluids

The hydrophobically associating polyacrylamide (HAPAM) obtained from produced fluids with compositional homogeneity was systematically investigated by zero-shear viscosity, fluorescence, sand-pipes experiment and adsorption behavior. The results showed that HAPAM obtained from produced solution through porous media has been possession in hydrophobic association character. The critical association concentration (CAC) determined by viscosity method, fluorescence spectroscopy method and micro-pore method have no obvious change compared with the original polymer. The hydrophobic associative capability of HAPAM obtained from produced fluids was smaller than that of original HAPAM. Compared to original PAM and PAM obtained from produced fluids, HAPAM obtained from produced fluids still exhibits promising applied potential. It reveals the possibility that HAPAM obtained from produced could be re-used for enhance oil recovery.