丙烯酰胺、3-丙烯酰胺-3-甲基丁酸钠和N-烷基丙烯酰胺三元共聚物的溶液特性研究

讨论了丙烯酰胺、3-丙烯酰胺-3-甲基丁酸钠和N-烷基丙烯酰胺三元共聚物(CAANA)的水溶液特性,并与部分水解聚丙烯酰胺(HPAM)水溶液特性相比较。芘荧光光谱分析和激光光散射仪测量结果表明。CAANA由于引入了疏水性单体,在水溶液中形成了分子间的疏水缔合作用,并使得CAANA在水溶液中具有较大的均方旋转半径,相对于HPAM,CAANA具有更好的耐温抗盐性能。在一定范围内,CAANA中引入的疏水性单体形成的缔合作用愈强,愈有利于改善聚合物的耐温抗盐性能。     

疏水缔合(丙烯酰胺十六烷基二甲基烯丙基氯化铵-2-丙烯酰胺基-2-甲基丙磺酸)三元共聚物的合成与性能研究

疏水缔合水溶性聚合物是指在聚合物亲水性大分子链上引入少量疏水基团的一类水溶性聚合物[1～5].在水溶液中,疏水基团之间由于憎水作用而发生聚集,使大分子链产生分子内与分子之间缔合.在临界缔合浓度以上,以分子间缔合为主,增大了流体力学体积,因此,具有较好的增粘作用.疏水基的加入可大幅度地改变聚合物的流变性能.在聚合物驱油中的流度控制,提高波及效率、以及调剖中起到非常重要的作用.     

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.     

低浓度HPAM/AlCit交联聚合物溶液性质研究

采用粘度法、扫描电镜（SEM）、核孔膜过滤、动态光散射（DLS）和27Al NMR法，研究了高分子量低浓度的部分水解聚丙烯酰胺（HPAM）与柠檬酸铝（AlCit）体系交联反应过程溶液性质变化.结果表明，HPAM与AlCit反应在低剪切速率时体系粘度随反应进行而降低，在剪切速率较高时具有剪切稠化现象，HPAM与AlCit反应过程中交联态Al的自旋 晶格弛豫时间随反应进行变短.低浓度的HPAM与AlCit发生分子内交联反应形成交联聚合物线团（LPC）在水中的分散体系，即交联聚合物溶液（LPS）.交联聚合物溶液中LPC的平均流体力学半径约为238 nm，其形态接近球形，具有多分散性. LPS对1.2 μm核孔膜的封堵程度与其反应时间有关.     

耐温抗盐驱油聚合物溶液黏弹性

对3种不同结构类型的耐温抗盐驱油聚合物〔高分子量聚丙烯酰胺(HPAM)、磺化聚丙烯酰胺(S-HPAM)和疏水缔合聚丙烯酰胺(A-HPAM)〕的溶液黏弹性能进行了研究。在温度85℃下,通过稳态剪切和动态剪切试验,考察了质量浓度和矿化度对聚合物溶液黏弹性的影响。结果表明,随剪切速率增加,溶液表观黏度逐渐降低。质量浓度越高,溶液的储能模量(G')和损耗模量(G″)越大。由动态剪切实验数据,计算得到第一法向应力差(N1)。随质量浓度增加,聚合物溶液的N1逐渐增大;随矿化度增加,聚合物溶液的N1出现不同盐敏感区域,说明不同结构类型的驱油聚合物溶液对矿化度的弹性响应不同。研究结果为高温高盐油藏聚合物驱剂的选择及开发提供了理论参考。     

驱油用聚丙烯酰胺分子量测试的光散射研究

利用旋转流变仪分析了超高分子量部分水解聚丙烯酰胺溶液的流变性质,并根据光散射动态模式分析了其在不同浓度和不同盐离子浓度下的尺寸分布.建立了利用多角度激光光散射准确测量驱油用超高分子量聚丙烯酰胺重均分子量(Mw)、均方根回转半径()和第二位力系数值(A2)的方法.准确测量了商品化驱油用超高分子量聚丙烯酰胺FP3630S的这3个参数,分别为Mw=(1.33±0.06)×107,     

一种水溶性疏水缔合聚合物二临界缔合行为研究

对三元共聚疏水缔合聚合物（丙烯酰胺／十八烷基二甲基烯丙基氯化铵／苯乙烯）的临界缔合浓度进行研究,发现其具有二临界缔合现象以及其在二临界缔合浓度附近不同的耐温抗盐的流变行为。研究结果表明,该疏水缔合聚合物的第一临界缔合浓度（C1^＊）为500mg／L,第二临界缔合浓度（C2^＊）为2400mg／L;C2^＊附近聚合物溶液的耐温性能较差;抗盐性能表现出三种不同的情况：随着盐质量浓度的增加,C〈C1^＊时,溶液粘度下降;C1^＊〈C〈C2^＊时,溶液粘度先增加后下降;C〉C2^＊时,溶液粘度先快速增加,后缓慢增加,最后下降。     

低浓度部分水解聚丙烯酰胺/柠檬酸铝交联体系剪切稳定性研究

采用粘度法、核孔膜过滤和动态光散射(DLS)法,研究了高分子量低浓度的部分水解聚丙烯酰胺(HPAM)与柠檬酸铝(AlCit)反应所形成的交联体系的剪切稳定性和HPAM剪切降解后与AlCit反应所形成的体系的封堵性能及降解机理.研究结果表明,低浓度的HPAM与AlCit反应所形成的交联聚合物体系随剪切速率增加,其对1.2μm的核孔膜的封堵能力降低.HPAM稀溶液剪切降解后再与AlCit反应,低剪切速率对其封堵性能影响较小,而高剪切速率会使得其封堵性能大大降低.HPAM/AlCit交联体系和HPAM剪切降解后形成的交联体系的封堵性能下降的原因是HPAM/AlCit交联体系中交联聚合物线团(LPC)尺寸和HPAM中高分子线团的尺寸变小.     

化学驱油过程中部分水解聚丙烯酰胺的二级结构研究

高分子量聚丙烯酰胺水溶液因其显著的增粘作用与粘弹性而在三次采油中得到广泛应用 .多年来大庆油田采用注入部分水解聚丙烯酰胺 (HPAM)水溶液驱油 ,实践证明 ,此法可大幅度提高原油采出率[1,2 ] .关于聚丙烯酰胺及其部分水解产物 (结构上等价于丙烯酰胺与丙烯酸的无规共聚物 )的链结构评价及其同高价离子的络合作用已有一些报道 [3～ 6] .在聚合物驱油过程中 ,HPAM水溶液在地下岩层中流动时间较长 ,实验室难以模拟 ,有关 HPAM流经地下岩层后的结构研究尚未见报道 .评价化学驱油油田矿场采出液中 HPAM的链结构 ,并探讨其结构变化机理…     

Self-assembly of hydrophobic associating polyacrylamide prepared by aqueous dispersion polymerization

Abstract

Hydrophobic 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.     

兼具有强阴离子性与疏水缔合性的丙烯酰胺三元共聚物

在微乳液介质中实施了丙烯酰胺 (AM)、苯乙烯 (St)、2 丙烯酰胺基 2 甲基丙磺酸钠 (NaAMPS)的共聚合 ,制备了既含有强阴离子性基团 (—SO3Na)又含有疏水基团 (St)的丙烯酰胺三元共聚物AM NaAMPS St;通过红外光谱法、紫外分光光度法及元素分析法对共聚物的结构及组成进行了表征 ;稀释外推粘度法测定了共聚物的特性粘数 ;测定了共聚物纯水溶液及盐水溶液的表观粘度 ;荧光探针法考察了三元共聚物的疏水缔合性以及离子基团对疏水缔合性的影响规律 .实验结果表明 ,在聚丙烯酰胺 (PAM )分子主链上同时引入强阴离子性基团与疏水基团后 ,阴离子的电粘效应与疏水基团的疏水缔合作用相互协同 ,会使共聚物水溶液的黏度显著提高 ;盐溶液对疏水缔合作用的增强效应与强阴离子基团对盐的较大容忍度相互结合 ,会使共聚物水溶液的抗盐性能明显得以提高 ;大分子链上的强阴离子基团磺酸根的存在 ,在一定程度上会削弱疏水基团之间的疏水缔合作用 ,即对疏水基团的疏水缔合行为会产生一定的负性影响 .     

聚丙烯酰胺的形态结构研究

本文用电子显微镜深入的研完了部分水解聚丙烯酰胺在水溶液中的形态。给出大分子的伸展网状结构是其稀溶液高粘度的结构本质。并详细讨论了聚合物的水解度、分子量、外加盐种类及波度与分子聚集状态的关系。     

Interaction Between the Hydrophobically Modified Polyacrylamide and HPAM-Flooding Produced Liquid

In order to utilize the produced liquid of hydrolyzed polyacrylamide (HPAM) flooding to enhance oil recovery, the interaction between hydrophobically modified polyacrylamide (HMPAM) and the produced liquid of HPAM flooding was investigated. The viscous characteristic of HMPAM in aqueous solution was investigated by Ubbelohde viscometer. The results show the intrinsic viscosity of HMPAM in aqueous solution is higher than that of HPAM, indicating that HMPAM has better effect on increasing the viscosity of aqueous solution. The viscosity of the complex system consisted of HMPAM and the produced liquid from HPAM flooding is lower than that of the HMPAM system, but higher than that of the HMPAM/HPAM complex system in mineralized water. In order to investigate the major factor of the influence on the viscosity of the HMPAM/produced liquid complex system, the viscosities of HMPAM/HPAM (and hydrolyzed HPAM with different hydrolysis degree) in distilled water and in mineralized water were studied. The fluorescence spectrum and transmission electron microscopy measurements were carried out to investigate the interaction between HPMAM and produced liquid from a microscopic perspective. These results are useful for farther enhancing oil recovery after HPAM flooding.     

表面活性单体NaAMC_(14)S/丙烯酰胺共聚物的分子链微结构与疏水缔合性

在实施丙烯酰胺型阴离子表面活性单体2-丙烯酰胺基十四烷磺酸钠(NaAMC14S)与丙烯酰胺(AM)水溶液均相共聚合过程中,分别通过改变AM与NaAMC14S的投料比、改变外加电解质NaCl的加入量以及引发剂的用量,制备了分子链微结构系列变化的具有微嵌段结构的共聚物NaAMC14S/AM;采用荧光探针法与表观粘度法研究了共聚物分子链微结构与其疏水缔合性能之间关系,探索了共聚物分子链中疏水微嵌段含量、疏水微嵌段长度及共聚物分子量诸微结构因数对共聚物疏水缔合性的影响.结果表明,共聚物NaAMC14S/AM的疏水缔合性随着疏水微嵌段含量的增加而增强,随着疏水微嵌段长度的增长而增强,当疏水微嵌段含量和嵌段长度一定时,共聚物的疏水缔合性随分子量的增大而增强.     

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.     

丙烯酰胺型阴离子表面活性单体与丙烯酰胺共聚物水溶液的流变特性

以丙烯酰胺型阴离子表面活性单体2-丙烯酰胺基十四烷基磺酸钠(NaAMC14S)为共单体,与丙烯酰胺(AM)的水溶液均相共聚合,使NaAMC14S的浓度分别处于临界胶束浓度上下,分别制备了具有无规结构与微嵌段结构的两类共聚物;用红外光谱法对共聚物的结构进行了表征,使用乌氏粘度法测定了特性粘数,相对表示出了共聚物的分子量;采用荧光探针法与表观粘度法重点研究了两类共聚物的疏水缔合性与水溶液的流变特性.研究结果表明,具有微嵌段结构的共聚物具有很强的疏水缔合性,当其水溶液的浓度达0.2wt%后,表观粘度迅速提高;其水溶液的切力变稀行为具有明显的可逆性,表现出强的抗剪切性能.本研究中特别发现,具有微嵌段结构的共聚物其盐水溶液的表观粘度远高于纯水溶液的表观粘度,当共聚物浓度为0.3wt%、CaCl2浓度为2wt%时,溶液的表观粘度竟然提高了3个数量级,表现出独特的正性盐敏性(即遇盐变稠).     

聚丙烯酰胺类疏水缔合物的增黏因素研究

合成了6种不同修饰度的聚丙烯酰胺疏水聚合物(PAM1~PAM6), 考察了聚合度、 共聚物片段含量及疏水基团大小等内部因素和聚合物的抗剪切能力、 剪切恢复性及抗盐性等外部因素对这些疏水聚合物分子间、 分子内缔合的影响规律.     

Kinetic behavior in self-assembly process of associative polymer solutions

Using associative polymers with different micro-block length (N_H), their kinetic behaviors in the self-assembly process have been discussed with steady flow, step shear rate and dynamic light scattering (DLS) experiments. The results showed that the N_H is the most important parameter to affect rheology of associative polymers, and the equilibrium time and viscosity recovery are an obvious difference from seconds to hours after violent pre-shearing. With DLS data, the hydrophobic micro-zone size is always a polydispersion distribution, and gradually concentrated three scales of size, the associative polymers with higher N_H values have a longer time to reach equilibrium state. The kinetic behavior of associative polymers has a greater potential to apply in enhanced oil recovery (EOR) field, we conclude that the polymers with medium associative strength have a smaller shear thinning index and higher viscosity recovery, and may satisfy the polymer flooding requirements of displacement efficiency and injectivity.