部分水解法制备高分子量水溶性(丙烯酰胺/丙烯酸/2-丙烯酰胺-2-甲基丙磺酸)三元共聚物

系列的高分子量水溶性丙烯酰胺 /丙烯酸 /2 丙烯酰胺 2 甲基丙磺酸 (AM/AA/AMPS)三元共聚物(P3A)由相应的 (AM/AMPS)二元共聚物通过部分水解方法制得 .聚合物的结构和组成使用电位滴定和13 C NMR谱测定 ,得到的结果指出 ,在设定的试验条件下 ,水解过程中 ,高分子链上AMPS单元具有充分的稳定性 ,而丙烯酰胺基平稳地转变为丙烯酸 .在所有不同聚合物 (P2A)情况下 ,由于阴离子基团和OH-离子的静电相斥作用 ,酰胺基的水解反应均遵循自动减缓动力学的模式 ,同时 ,最后反应转化率趋向极限 ,AM剩余值位于 3 0mol%左右 ,另外对各种三元共聚物 (P3A)的溶液特性粘数和组成的关系亦作了详细的研究 .     

一种两性三元共聚物的合成

选用聚乙二醇二丙烯酸酯(PEGDA)为扩链剂,以丙烯酰胺(AM)、2-甲基-2-丙烯酰胺基丙磺酸(AMPS)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为主单体,采用水溶液聚合方法合成了两性三元共聚物AM/AMPS/DMC;测定了共聚物的性能,并利用红外光谱研究了其分子结构.结果表明,所合成的共聚物具有良好的耐酸和高温稳定性,以及高抗剪切率.     

DSC研究高吸水树脂吸水性能与分子结构的关系

以丙烯酸(AA)、丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为共聚单体合成了聚丙烯酸-丙烯酰胺-2-丙烯酰胺基-2-甲基丙磺酸(PAA-AM-AMPS)三元共聚物高吸水树脂.利用茶叶袋法测定了其最大吸水倍率,通过差示扫描量热仪(DSC)测定并比较了含水量为50%,75%和91%的各种水凝胶的自由水和结合水含量.结果表明在蒸馏水和生理盐水中高吸水树脂的最大吸水倍率分别为1900g/g和185g/g,共聚物的结合水含量随着AMPS和AA含量增加及AM含量的减少而增大;在0.9%生理盐水中,结合水含量随着AMPS和AM含量增加及AA含量的减少而增大,共聚物和均聚物高吸水树脂的最大吸水倍率呈现出与结合水含量相同的变化规律.     

丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物的形态结构研究

 本工作应用透射电子显微镜研究了丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物(AM/AMC₁₆SNH₄)的形态结构.给出共聚物在水溶液中具有伸展网状结构,并存在一定程度的疏水基因间的缔合作用.是一种在耐盐性和储存稳定性方面有明显改善的新型改性聚丙烯酰胺.     

离子液体中AM/AMPS/N8AM三元共聚物的合成及溶液性能

以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为亲水单体, 以N-辛基丙烯酰胺(N8AM)为疏水单体, 在离子液体[bmim]BF4中实现了疏水缔合丙烯酰胺三元共聚物的合成.     

稳态和动态荧光研究疏水缔合共聚物P(AM/POEA)的自缔合行为和聚集体

应用稳态和动态荧光光谱方法,包括荧光探针、标记荧光和荧光淬灭等研究了共聚物P(AM/POEA)在水溶液中的自缔合性质.这种共聚物由丙烯酰胺(AM)和少量疏水单体2-苯氧乙基丙烯酸酯(POEA)组成.实验结果表明这类共聚物的自缔合行为和聚集体结构主要取决于聚合物的链结构和浓度.由胶束共聚合方法得到具有多嵌段结构的共聚物,它们容易发生疏水缔合,并产生很强的增粘作用,而由普通共聚合方法得到的无规共聚物却没有这些性质.同时这类聚合物的缔合类型及其增粘能力也直接与共聚物中的疏水体含量相关,随疏水体含量增加,由于分子间和分子内缔合的竞争,出现粘度先增后降的现象.在荧光研究的基础上提出了多分子聚合物聚集体的结构模型,它随聚集体浓度增加,进一步形成多联聚集体和网状结构.同时还观察到聚集体中疏水体有序排列现象.     

水溶性疏水缔合聚合物-膨润土纳米复合材料的研究

以有机改性膨润土、2-丙烯酰胺-2-甲基丙磺酸（AMPS）、 N,N-二甲基丙烯酰胺（DMAA）和季铵盐单体D-C₁₆Br为原料，通过原位聚合制备了一种新型水溶性疏水缔合聚合物-膨润土纳米复合材料。利用红外光谱、X-射线衍射仪对产物结构进行表征，并通过与纯共聚物AMPS/DMAA/D-C₁₆Br相比，研究了纳米黏土材料的引入对共聚物性能的影响。结果表明：在膨润土促进聚合物分子形成疏水缔合结构的作用下，具有复合插层结构的复合材料在热稳定性、耐温性、抗剪切性和黏弹性方面均优于纯聚合物，表明该纳米复合材料较纯共聚物具有良好的应用前景。     

水溶性AM/AA/AMPS共聚物的高温水解

丙烯酰胺;水溶性AM/AA/AMPS共聚物的高温水解;丙烯酸;甲基丙磺酸;水解反应;反应机制     

粘度和光谱方法研究二元阴离子型丙烯酰胺共聚物(P3A)在不同pH水溶液中的构象变化

采用粘度和光谱方法,研究了强酸性和弱酸性2种阴离子型单体与丙烯酰胺的三元共聚物(P3A)在稀水溶液中pH诱发的构象变化,P3A聚合物由丙烯酰胺(AM)和强酸性离子单体(AMPS)及弱酸性离子单体(AA)组成.试验结果表明P3A聚合物溶液的粘度随pH呈现非单调的增长关系,在pH为4～5范围内产生急剧的升高,这现象归因于聚合物链团从紧密状态向膨胀状态迅速的转变.这两种状态的溶液粘度变化幅度和聚合物P3A中AMPS和AA组合比例紧密相关,芘探针在聚合物P3A溶液中的荧光强度和pH的关系呈现类似粘度变化的结果.在低pH值时,发现单一弱酸离子共聚物(P2AA)溶液发生相分离,然而在含有强酸单元(AMPS)的P3A聚合物情况下,这种现象不再产生.     

丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物的形态结构研究

本工作应用透射电子显微镜研究了丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物(AM/AMC_(16)SNH_4)的形态结构.给出共聚物在水溶液中具有伸展网状结构,并存在一定程度的疏水基因间的缔合作用.是一种在耐盐性和储存稳定性方面有明显改善的新型改性聚丙烯酰胺.     

二元阴离子型丙烯酰胺共聚物在二价金属离子存在下相分离行为的研究

水溶性丙烯酰胺类共聚物 ,作为粘度改性剂 ,在工业上已得到广泛应用 .特别近年来 ,它们大量应用于石油工业强化采油技术 ,引起了人们很大的重视[1] .目前 ,这类用途的聚合物 ,主要在聚丙烯酰胺结构中 ,引入阴离子组分和不断增高产物分子量的方法 ,以提高聚合物溶液粘度和增粘效果 ,然而 ,在二价金属离子 (如Ｃａ2 + ,Ｍｇ2 + 等 )存在下 ,羧酸阴离子型丙烯酰胺类共聚物很容易络合发生沉淀 ,从而失去增粘作用[2 ] .同时这类聚合物中酰胺基不稳定 ,易发生水解反应转化为羧酸基 ,并随温度升高而加剧[3 ] ,因此在温度较高的应用条件下 ,二价金属…     

AMPS/DMAM/FA/AM共聚物的合成及溶液性能研究

本文采用氧化还原引发体系合成了AMPS（2-丙烯酰胺基-2-甲基丙烷磺酸钠）／DMAA（N,N-二甲基丙烯酰胺）／FA（富马酸）／AM（丙烯酰胺）共聚物,研究了共聚物的水溶液性能。结果表明,随聚合物浓度的增加,溶液表观粘度急剧增加;无机盐的加入使聚合物溶液的粘度下降,但很快稳定;随老化温度的提高,聚合物溶液的粘度有所增加;共聚物试样在盐水中表现出随剪切速率的增加,表观粘度增加。     

中低渗透高温高盐油藏驱油共聚物P(AM/AMPSNa/AANa)的合成及性能

在中低渗透高温高盐油藏聚合物驱技术中, 超高相对分子质量聚丙烯酰胺(HPAM)存在不易注入、剪切降粘显著和耐温抗盐性能差等问题。 本文以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体, 采用过硫酸胺(NH₄)₂S₂O₈和甲基丙烯酸N, N-二甲氨基乙酯(DMAEMA)作为支化结构复合引发体系, 通过共聚后水解工艺, 合成含支化结构耐温抗盐驱油共聚物P(AM/AMPSNa/AANa)。 研究了引发温度、链转移剂用量、引发剂用量对共聚物特性黏数的影响, 并通过红外光谱(IR)和¹³C NMR表征了产物结构。 筛选特性黏数1915 mL/g左右的共聚物, 进行性能评价。 实验结果表明, 共聚物具有优异的耐温抗盐性能、抗剪切性能、抗老化性、注入性和驱油性能, 可应用在中低渗透高温高盐油藏三次采油中。     

Effect of sodium dodecyl benzene sulfonate to the displacement performance of hyperbranched polymer

Experimental studies were conducted to realize displacement performance effect of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on hyperbranched poly(AM/AA/AMPS/GA), which was successfully synthesized via free radical polymerization using modified dendritic functional monomer (GA), acrylamide (AM), acrylate (AA), and 2-acrylamido-2-methyl propane sulfonic acid (AMPS). Compared with individual polymer, SP (surfactant polymer) binary systems showed lower apparent viscosity, interfacial tension, and hydrodynamic radius as the result of the electrostatic repulsion between the tail end of hydrophilic polymer branched chain and the head of the surfactant. It was found from abundant static adsorption and dynamic retention tests that the values of static adsorption and dynamics retention of SDBS which is mixed with hyperbranched polymer decrease due to the competitive interaction. However, unlike this phenomenon, SDBS would heighten the dynamic retention value of poly(AM/AA/AMPS/GA), resulting in addition of residual resistance factor. Oil displacement experiment indicated that SP solutions have greater capability of enhance oil recovery than individual polymer under same conditions.     

新型疏水缔合聚合物P(AM/POEA)与表面活性剂的相互作用

采用粘度法、荧光探针和透射电镜研究了新型疏水缔合聚合物P(AM/POEA)和表面活性剂SDS和CTAB在水溶液中的相互作用. 聚合物P(AM/POEA)结构中, 疏水体(2-苯氧乙基丙烯酸酯)呈嵌段状无序地分布在聚丙烯酰胺主链上. 这类聚合物很容易和表面活性剂相互作用, 通过疏水缔合, 形成混合胶束状聚集体, 导致溶液粘度剧增. 随聚合物溶液中SDS的加入, 溶液粘度发生大幅度起伏变化, 出现最大值. 粘度最大值对应的表面活性剂浓度c_S,max位于表面活性剂CMC附近, 并发现它的位置不随聚合物微结构而变化. 然而它们缔合作用的增粘程度却与聚合物疏水体含量X_H及疏水嵌段尺寸N_H有关. 在实验浓度范围内, X_H和N_H愈大, 溶液的粘度越高. 此外用透射电镜直接观察到聚合物/表面活性剂体系中聚集体的交联结构形貌.     

Rheological properties and enhanced oil recovery performance of a novel sulfonate polyacrylamide

A novel hydrosoluble sulfonate copolymer (SPAM) containing sulfonic acid groups was synthesized under mild conditions with Acrylamide (AM), 2-(Dimethylamino) ethyl methacrylate (DMAEMA) and 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propane sulfonic acid (AMPS) as monomers by segmentation initiation with 2,2'-azobis[2-methylpropionamidine] dihydrochloride and redox initiation system, respectively. The structures of copolymers were characterized by infrared (IR) spectroscopy, ¹H NMR spectroscopy and thermogravimetric analysis. The rheological properties of the copolymer solution at different shear rate, temperature and salt concentration were investigated. The shear-tolerance, temperature-tolerance and salt-tolerance of the novel synthetic hydrosoluble sulfonate copolymer are improved remarkably compared with partially hydrolyzed polyacrylamide (HPAM). The synthetic copolymer solution possesses a higher viscosity retention rate (53.3%) than HPAM (35.3%) at the total salinity of 20000 mg/L when temperature changed from 30°C to 99°C. The enhanced oil recovery (EOR) of the synthetic copolymer was performed by core flood, and the EOR degree of the synthetic copolymer in the 20000 mg/L salt solution at 80°C was better than that of HPAM. Compared with HPAM flooding, the EOR with the synthetic copolymer flooding was increased by 6.8% at 80°C.     

Synthesis and characterization of a novel amphiphilic copolymer containing β-cyclodextrin

In this article, maleic anhydride was used to attain the modified β-cyclodextrin (MAH-β-CD), and the MAH-β-CD was copolymerized with acrylamide (AM), acrylic acid (AA), and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) via free radical copolymerization. The polymerization conditions were optimized through single-variable method. Subsequently, the copolymer structure was characterized through Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (¹HNMR) spectroscopy, and scanning electron microscopy (SEM). The three-dimensional network structure formed in aqueous solutions was observed via experimental results of SEM. Subsequently, several aspects of the properties of the copolymer, such as temperature tolerance, shear tolerance, salt resistance, and oil displacement ability, were investigated by comparing with hydrolyzed polyacrylamide (HPAM). Results indicate that the copolymer showed better performances than HPAM; thus, it could be concluded that the introduction of β-cyclodextrin in the polymer chain was helpful in enhancing the oil displacement efficiency in high-temperature and high-salinity oil field.     

Synthesis and properties of temperature-resistant and salt-tolerant tetra-acrylamide copolymer

Abstract

The acrylamide copolymer with acrylamide as its main monomer is a modified polyacrylamide. In addition, the acrylamide copolymer is generally to dissolve or swell in water and can be used as thickener, dispersant, flocculant and so on. Therefore, using Acrylamide AM, 2-acrylamide-2-methyl propanesulfonic acid AMPS, dimethyldodecyl (2-acrylamidoethyl) ammoniumbromide AQ₁₂ and vinyltriethoxysilane VTEO as raw materials so that a series of four-membered acrylamide copolymers are prepared in aqueous solution polymerization. The amphoteric structure in the polymer has a unique anti-polyelectrolyte behavior when it is electrically neutral, which can significantly improve the salt resistance of the aqueous polymer. In addition, the hydrolysis of the vinyltriethoxysilane containing silicon structure by hydrophobic association can improve the temperature resistance of the polymer. The optimal reaction conditions were determined by orthogonal experiment: the reaction temperature was 10?°C; the initiator concentration was 0.05?mol%; the monomer concentration was 25?wt% and the pH was 7. Properties of polymer solution indicated that the series of tetra-copolymer possessed salt-tolerant and heat-resisting performances. As an oil displacing agent, it can significantly improve the efficiency of oil displacement, and particularly highlights the effect of 4-member copolymer as an oil displacing agent.     

生物降解高分子——聚己内酯/聚氧乙烯/聚丙交酯三元共聚物水解行为的研究

以异辛酸亚锡为催化剂 ,通过聚乙二醇醚 (PEG)引发ε 己内酯和L 丙交酯开环聚合 ,制备了PCL/PEO/PLA三元共聚物 .研究了聚合物在 pH7 4磷酸缓冲溶液、37℃条件下的体外降解行为 .采用GPC、1H NMR、DSC和XRD技术研究了聚合物在水解降解过程中分子量、分子量分布、组成、吸水率、结晶性等的变化 .结果表明共聚物的吸水率随聚醚组分含量而增大 ;随水解材料的失重率增大 ,聚醚组分含量下降程度也加大 .此外研究还表明 :聚合物中丙交酯组分含量高时 ,聚合物的结晶结构主要由PLLA形成 .由于聚合物的水解降解首先发生在无定形区和结晶区边缘 ,随着共聚物的降解、结晶性的PLLA低聚物的生成 ,导致了共聚物的分子量呈双峰分布