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1.
强阴离子型丙烯酰胺共聚物P(AM-co-NaAMPS)的结构与性能   总被引:11,自引:0,他引:11  
在水介质中实施了丙烯酰胺 (AM)与 2 丙烯酰胺基 2 甲基丙磺酸钠 (NaAMPS)的溶液共聚合 ,制备了组成系列变化的强阴离子型共聚物P(AM co NaAMPS) ;通过红外光谱法与元素分析法对共聚物的组成进行了表征 ;稀释外推粘度法测定了共聚物的特性粘数及Huggins常数 ;测定了共聚物纯水溶液及盐水溶液的表观粘度及高温下共聚物盐水溶液的粘度保持率 ;重点考察了共聚物的结构与组成对其各种性能的影响规律 .实验结果表明 ,在聚丙烯酰胺 (PAM)分子主链上引入NaAMPS链节后 ,磺酸根的强阴离子性与庞大侧基的位阻效应 ,赋于共聚物P(AM co NaAMPS)以优良的溶解、增稠、耐温与抗盐性能 ,且这些性能随共聚物的结构与组成的改变发生规律性的变化 .  相似文献   

2.
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。  相似文献   

3.
丙烯酰胺-苯乙烯双亲嵌段共聚物水溶液的粘度性能   总被引:4,自引:0,他引:4  
通过改变丙烯酰胺 (AM)与苯乙烯 (St)两单体的投料比 ,在微乳液介质中制备了分子组成系列变化的丙烯酰胺 苯乙烯双亲嵌段共聚物 (PAM b PSt) ,使用旋转粘度计测定了共聚物水溶液的表观粘度 ,详细考察了共聚物浓度、共聚物链结构、剪切速率、盐度及温度等因素对共聚物水溶液表观粘度的影响规律 .研究结果表明 ,由于PAM b PSt分子链中的PSt疏水嵌段链段之间具有强的疏水缔合作用 ,导致其具有独特的流变性能 .当共聚物水溶液的浓度高于某一临界值后 ,疏水缔合作用以分子间的缔合为主 ,大分子链之间会形成动态物理交联网络 ,增大了流体力学体积 ,使PAM b PSt水溶液可产生良好的增稠性能 ;疏水缔合作用是一吸热过程 ,升高温度有利于分子间的缔合 ,因此PAM b PSt水溶液具有良好的耐温性 ;聚合物水溶液中盐类物质的存在 ,会增强溶剂的极性 ,有利于分子间的缔合 ,使PAM b PSt水溶液具有良好的耐盐性 .  相似文献   

4.
运用分子设计的方法论,从理论与实践上对主链聚合物的组成、分子量、结构与聚集态,枝链聚合物的结构、与主链聚合物的相容性,不同条件下的反应能力,枝链长度、枝链度及其位置分布以及接枝化合物结构对溶解能力、增粘性能。流变与异常粘—温依赖关系、表面性能等影响进行了探讨。在此基础上论证了以木薯淀粉为主链聚合物、以芳环及顺酐、甲基丙烯酸为基本单元的共聚物为枝链聚合物进行接枝共聚,以制备耐温、抗剪切降解、增稠能力与表面活性作用良好水溶性的新型高聚物驱油用材料的可能性与现实性。并为进一步的分子设计研究打下了基础。  相似文献   

5.
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。  相似文献   

6.
超分子树枝聚合物起源于聚合物链结构的2个重要进化(树枝链和超分子),是通过建筑模块在芯、支化单元或表面的分子自组装(非共价键连接)生成的树枝聚合物,具有独特的结构特征和新颖的物理、化学等功能。超分子树枝聚合物的进一步自组织可形成液晶态或柱状体等有序结构。超分子树枝聚合物可分为氢键型、金属配位型、π-π堆叠型、离子型、拓扑型(含轮烷和索烃结构)、混合型(含2种或2种以上不同非共价键)等类型。本文综述各种类型超分子树枝聚合物的合成、结构、聚集态和应用。  相似文献   

7.
分子复合法制备新型聚合物驱油剂CMC/P(AM-DMDAAC)   总被引:6,自引:0,他引:6  
通过具有互补结构的阴离子聚合物羧甲基纤维素(CMC)与阳离子聚合物聚(丙烯酰胺-二甲基二烯丙基氯化铵)[P(AM-DMADAAC)]间的聚电解质分子复合作用,制备了分子复合型CMC/P(AM-DMDAAC)新型驱油剂,电导率测定及紫外光谱分析结果表明,CMC与P(AM0DMDAAC0可以在水相通过库仑力形成的相聚电解质复合溶液,由于分子复合形成的独特超分子结构,复合溶液粘度显著增加,分别为组分聚合物溶液的5.2倍和9.0倍,在高温和高剪切环境中的粘度保持能力也明显优于组分聚合物。  相似文献   

8.
高分子量聚丙烯酰胺(PAM)和部分水解聚丙烯酰胺(HPAM)是目前世界上生产量最大的合成水溶性高分子。由于它们在水溶液中只要很低的浓度就具有高粘度的特件,故广泛用作提高石油采收率的堵漏剂和增粮剂。 部分水解聚丙烯酰胺的分子链上有若干离子离解性基团,是具有柔性链构象的烯类聚电解质,在水溶液中的粘度对加盐浓度比较敏感。过去的有关工作多在中盐浓度区,对高盐浓度区只有定性结果。本工作主要研究该聚合物在高盐溶液中的行为。  相似文献   

9.
聚丙烯酰胺稀溶液的分子模拟   总被引:2,自引:0,他引:2  
聚丙烯酰胺(PAM)是一类重要的线性水溶性聚合物,具有"百业助剂"之称,因此对其溶液性质的研究意义重大.在溶液质量浓度约为1g·mL-1的基础上,分别构建了含有不同水分子数的溶液模型.采用分子动力学(MD)方法模拟分析了不同温度下非离子型的聚丙烯酰胺(PAM-H)和阴离子型的聚丙烯酰胺(HPAM)在纯水溶液及含不同质量分数NaCl的水溶液中的回旋半径(Rg).结果发现,不同温度下PAM-H和HPAM的抗盐性能的模拟结果与实验数据基本吻合,水分子数不同的溶液模型所得模拟结果趋势没有明显变化,为了提高模拟效率,选取含有2000个水分子的溶液模型分析HPAM链中氧负离子及氧原子的径向分布函数,从微观结构模拟说明了HPAM水溶液粘度随NaCl质量分数增加而减小,且HPAM比PAM-H具有较好的增粘效果及较差的抗盐性能的原因.  相似文献   

10.
采用热分析方法并配合红外光谱法,研究了四氟乙烯与六氟丙烯共聚物(FEP)的分子链结构和聚集态结构。发现FEP共聚物分子链结构是由共聚链段和均聚链段组成的。提出了共聚物的聚集态模型和热裂解、热氧化裂解机制,成功地解释了FEP共聚物的热行为、热稳定性和热氧化过程。  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

15.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

16.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

17.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

18.
19.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

20.
Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.  相似文献   

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