一种四元共聚物磷酸盐粘土稳定剂的合成与性能研究

以丙烯酰胺(AM)、丙烯酸(AA)、(1-二甲氨基)-烯丙基磷酸(DMAAPA)和N-烯丙基油酰胺(CON)为原料,制备了一种水溶性磷酸盐共聚物AM/AA/DMAAPA/CON。确定了最佳合成条件:AM:AA:DMAAPA:CON=69.6:30.0:0.2:0.2(wt%)、pH=7、引发剂加量为0.2 wt%、单体浓度20 wt%、聚合反应温度40℃。对共聚物进行了IR和NMR表征。该聚合物表现出较好的增粘性、抗剪切、耐温和耐盐性能;0.8 wt%的共聚物溶液防膨率达到80.12%,与1.0 wt%的KCl复配后,防膨率达到96.54%。     

SET-LRP法制备星型疏水缔合水溶性聚合物

采用丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸钠(NaAMPS)以及N-叔丁基丙烯酰胺(NtBA)为共聚单体,以Cu~0粉/三(2-二甲氨基乙基)胺(Me_6-TREN)为催化体系,四氯化碳(CCl_4)为引发剂,利用单电子转移自由基聚合(SET-LRP)方法合成星型疏水缔合水溶性聚合物P(AM/NtBA/NaAMPS)。采用控制变量法分别考察了引发温度、疏水单体含量、AMPS含量、引发剂用量、催化剂铜、单体浓度等因素对聚合物相对分子质量的影响,确定了最佳聚合条件并考察了聚合物的耐温抗盐性能。结果表明,当单体浓度为35%,引发温度为25℃,AM、AMPS、NtBA分别占单体总量的93.6%、5%、1.4%(摩尔比),引发剂质量分数为0.4942%,催化剂铜的质量分数为0.0848%,钝化剂的质量分数为0.1192%时,所得星型疏水缔合水溶性聚合物P(AM/NtBA/NaAMPS)的相对分子质量出现最高值为267万,同时具有一定的耐温抗盐性,其溶液性能与线型化的P(AM/NtBA/NaAMPS)相似,且在相同浓度下CaCl_2对聚合物表观粘度的影响比NaCl大。     

AM/AA/APEG/NANB共聚物的合成与性能研究

通过丙烯酰胺(AM),丙烯酸(AA),烯丙醇聚氧乙烯醚(APEG)和N,N-二烯丙基苄胺(NANB)制备共聚物P(AM/AA/APEG/NANB)。确定了最佳反应条件:m(AM)∶m(AA)=6.5∶3,APEG为5 wt%,NANB加量0.2 wt%,pH为7,反应温度40℃,引发剂0.4 wt%。通过IR和1H NMR确定了聚合物的分子结构,并对其进行性能测试。结果表明:2000 mg·L-1的AM/AA/APEG/NANB溶液具有较好的流变性能(120℃,粘度保留率:38.56%;1000 s-1,粘度保留率:17.93%)和抗盐性能(20 000 mg·L-1Na Cl,2000 mg·L-1Mg Cl2或Ca Cl2,粘度保留率分别为22.14%、18.34%和15.33%),且提高采收率可达16.12%。     

耐温耐盐AM-AMPS-DMDAAC-NEA共聚物粘土稳定剂的合成及性能研究

以丙烯酰胺(AM),2-丙烯酰胺-2-甲基丙磺酸(AMPS),二甲基二烯丙基氯化铵(DMDAAC)和N-烯丙基庚酰胺(NEA)制备了一种耐温耐盐AM-AMPS-DMDAAC-NEA四元聚合物。对该聚合物进行了红外、ESEM表征。考察了反应温度、pH值、引发剂加量、单体浓度、配比等对聚合物表观粘度的影响,确定了最佳的合成条件。抗温、抗盐、抑制钠蒙脱土(MMT)水化膨胀实验结果表明:在矿化度为12000mg/L或130℃条件下表观粘度保留率分别为70%和48.8%,同时该聚合物与KCl或NaCl复配能够显著降低MMT的晶间距。     

疏水缔合水溶性聚合物P(AM/NaAA/DiAC16)的合成与性能

以双烯丙基胺和1-溴代十六烷为原料合成了疏水单体N,N-双烯丙基十六胺,采取前加碱二元胶束共聚-后水解法合成了三元疏水缔合水溶性聚合物聚(丙烯酰胺/丙烯酸钠/N,N-双烯丙基十六胺)[P(AM/NaAA/DiAC16)],用FTIR、1H-NMR进行了结构表征;以芘为荧光探针,利用稳态荧光光谱法、粘度法研究了P(AM/NaAA/DiAC16)在水溶液的缔合行为.当x(DiAC16)=0.10～0.40 %时,在30℃、1mol·L-1NaCl溶液中,其Huggins常数KH小于0.80(144～0.294),表明稀溶液中缔合作用较弱.随聚合物浓度、疏水单体用量的增加,P(AM/NaAA/DiAC16)在二次蒸馏水中、1.000 mol·L-1 NaCl水溶液中,I1/I3值减少;在矿化度为19 334 μg/g盐水溶液中,水溶液的表观粘度增加、临界缔合浓度降低.结果表明,P(AM/NaAA/DiAC16)缔合行为取决于聚合物浓度、疏水单体用量及介质的极性.     

荧光探针法研究疏水改性聚丙烯酰胺溶液的疏水缔合行为

采用胶束共聚 共水解方法合成疏水改性水溶性聚合物聚(丙烯酰胺/丙烯酸钠/N 辛基丙烯酰胺)[P(AM/NaAA/C8AM)],并以芘为荧光探针,应用稳态荧光光谱法研究了它的疏水缔合行为。结果表明,随聚合物浓度、疏水单体摩尔分数、疏水侧链长和温度的增加,疏水缔合作用增强;不同疏水单体含量的P(AM/NaAA/C8AM)的临界缔合浓度为1.5~3.0 g/L;表面活性剂十二烷基硫酸钠(SDS)与P(AM/NaAA/C8AM)发生了强烈的疏水相互作用,形成混合胶束,得到SDS的临界胶束浓度(CMC)为8×10-3 mol/L;由于聚合物链上羧基的存在,使其具有良好的 pH敏感性,随 pH值的增大,P(AM/NaAA/C8AM)的疏水缔合作用呈现先减弱后恒定再增强的变化。     

AM-DMDAAC共聚物的合成

研究了丙烯酰胺(AM)与阳离子单体二甲基二烯丙基氯化铵(DMDAAC)的水溶液聚合，考察了引发剂用量、单体总浓度，pH值，n(AM)：n(DMDAAC)对聚合物阳离子度和特性粘度的影响。并对产物进行了IR和热分析。     

含环糊精结构四元共聚物驱油剂的制备及性能研究

以丙烯酸(AA)、丙烯酰胺(AM)、二烯丙基胺甲磺酸钠(SDMS)、6-O-烯丙基-β-环糊精(DPTD)为原料,合成了一种新型四元共聚物AA/AM/SDMS/DPTD。确立了该聚合物的最佳合成条件,通过红外光谱(IR)对该聚合物结构进行了表征。该聚合物具有较好的抗温、抗盐、流变性能:在120℃时,2 000 mg·L~(-1)的聚合物溶液的黏度保留率为58.8%;在10 000 mg·L~(-1)的NaCl浓度下,聚合物溶液粘度保留率达到10.6%;在1 000s~(-1)的剪切速率条件下,2 000 mg·L~(-1)的聚合物溶液的黏度保留率可以达到10.2%。通过室内模拟岩芯驱替实验表明,该聚合物能够将模拟原油采收率提高12.1%。     

对羟基苯甲酸印迹聚合物微粒的制备及其固相萃取应用

以对羟基苯甲酸(p-HBA)为模板分子,丙烯酰胺(AM)为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合法在乙腈溶剂中制备了p-HBA印迹聚合物微粒,研究了p-HBA加入量及聚合反应体系的总浓度对印迹聚合物结合性能的影响,采用色谱法对其进行了评价。结果表明,p-HBA的加入量及反应体系的总浓度对结合性能均有影响,当p-HBA加入量为1.0 mmol(与AM物质的量比为1:2)时,在37.5 mL乙腈中制得印迹聚合物P₂对p-HBA具有高的亲和力(k'=4.01)和选择性。将印迹聚合物P₂作为固相萃取填料,研究了分子印迹固相萃取p-HBA的方法,测得2种不同载样模式下p-HBA的柱容量分别为6.91 μg/100 mg和1.93 μg/100 mg,测得天麻样品中p-HBA的加标回收率为76.8%~86.6%(RSD=3.4%~6.2%)(n=3)。结果表明,采用沉淀聚合法以AM为功能单体制备的p-HBA印迹聚合物微粒适宜作为固相萃取填料,可实现天麻样品中p-HBA的选择性分离净化。     

离子液体中AM/ST二元共聚物的合成

采用1-丁基-3-甲基咪唑氟硼酸盐离子液体作为聚合反应介质,以偶氮二异丁腈(AIBN)为引发剂,丙烯酰胺(AM)为亲水单体,苯乙烯(ST)为疏水单体,合成了水溶性共聚物P(AM/ST).研究得到了适宜的反应条件:总单体在离子液体中的浓度为2mol/L,引发剂的浓度占总质量分数的2%,反应温度60℃,反应时间4h,AM与ST的物质的量比为98∶2,采用该反应条件所得到的聚合物的特性黏数为2.6.通过1HNMR,13CNMR和FIRT表征了聚合物的分子结构.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.