表活性单体NaAMCnS及其聚合物的合成及性能研究

针对疏水缔合聚合物水溶性不足的问题，本文合成了三种含烷基磺酸根的阴离子型表面活性单体2-丙烯酰胺基辛烷基磺酸钠（NaAMC₈S）、2-丙烯酰胺基十二烷基磺酸钠(NaAMC₁₂S)和2-丙烯酰胺基十八烷基磺酸钠(NaAMC₁₈S),通过氢谱、碳谱、高分辨质谱对其结构进行了表征。通过表面张力法和电导率法测定了NaAMC₈S和NaAMC₁₂S的临界胶束浓度；用荧光探针技术研究了其增溶作用；以偶氮二异丁脒盐酸盐（AIBA）为引发剂，在水溶液中研究了丙烯酰胺（AM）分别与NaAMC₈S、NaAMC₁₂S的二元共聚反应，通过控制AM与NaAMC₈S、NaAMC₁₂S的投料比制备得到两个系列聚合物P（AM/NaAMC₈S）、P(AM/NaAMC₁₂S),研究了表面活性单体含量对聚合物疏水缔合作用及耐温抗盐性能的影响。实验结果表明，NaAMC₈     

含孪尾型丙烯酰胺的HAPAM在新胶束聚合体系中的制备及其疏水缔合性

以表面活性单体2-丙烯酰胺基十二烷磺酸钠(NaAMC12S)为表面活性剂构建了新的胶束共聚合体系,实施了丙烯酰胺(AM)与N,N-二正十二烷基丙烯酰胺(DiC12AM)的胶束共聚合,制备了含孪尾型丙烯酰胺的疏水缔合聚丙烯酰胺(HAPAM),该聚合物为三元共聚物DiC12AM/NaAMC12S/AM.通过控制共聚合条件,制得了微结构系列变化的共聚物;采用红外光谱法表征了三元共聚物的化学结构,用荧光探针法与表观粘度法重点研究了共聚物DiC12AM/NaAMC12S/AM的大分子链微结构与其疏水缔合性的关系.结果表明:新胶束共聚合体系大大简化了胶束的共聚合操作,而且由于表面活性单体进入共聚物主链,使三元共聚物DiC12AM/NaAMC12S/AM具有更强的疏水缔合性.与由单尾型丙烯酰胺N-正十二烷基丙烯酰胺(C12AM)为疏水单体制备的HAPAM相比,由DiC12AM制得的HAPAM疏水缔合性更为显著.     

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.     

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…     

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。     

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.     

疏水缔合聚丙烯酰胺在表面活性单体胶束溶液中的制备及其流变特性

配制了表面活性单体2-丙烯酰胺基十二烷磺酸钠(NaAMC12S)与十二烷基硫酸钠(SDS)的胶束溶液,分别测定了强疏水单体N-正十二烷基丙烯酰胺(C12AM)在两种胶束溶液中的增溶性能;在此基础上,于两种胶束溶液中分别进行了丙烯酰胺(AM)与C12AM的胶束共聚合,制备了疏水缔合聚丙烯酰胺(HAPAM),它们分别为二元共聚物C12AM/AM与三元共聚物C12AM/NaAMC12S/AM;测定了两种共聚物的红外光谱;采用荧光探针法与表观粘度法重点研究了它们的疏水缔合性与流变性能.结果表明,在表面活性单体NaAMC12S的胶束溶液中,可顺利地实现AM与疏水单体的胶束共聚合,由于表面活性单体也参与了共聚合,故制得的产物为三元共聚物C12AM/NaAMC12S/AM;与在SDS胶束溶液中制备的二元共聚物C12AM/AM相比,前者的疏水缔合性更强,其强疏水缔合性以强疏水单体C12AM的贡献为主,以表面活性单体NaAMC12S的贡献为辅.     

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。     

疏水改性无规共聚物水凝胶体积相变研究

以偶氮二异丁腈(AIBN)为引发剂,合成了一系列疏水改性的甲基丙烯酸β-羟乙酯(HEMA)无规共聚物水凝胶,研究了离子强度、pH、温度等条件对凝胶体积相变的影响。结果表明,疏水基末端端基的疏水程度决定凝胶体积相变的速率,随着疏水性单体甲基丙烯酸酯烷基链的增长,凝胶的疏水性增强,凝胶的相转变pH向低pH处迁移;温度高于LCST时,分子间的氢键作用减弱,疏水基团间的相互作用加强,凝胶发生体积相变。     

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.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。