阳离子聚丙烯酰胺的反相乳液聚合

以丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体,Span80-Tween80为复合乳化剂,液体石蜡为连续相,通过反相乳液聚合法制备阳离子型高分子聚丙烯酰胺。研究了油水体积比对聚合物特性粘度的影响,乳化剂用量对聚合物特性粘度的影响,单体用量对聚合物特性粘度的影响,阳离子度对聚合物特性粘度的影响及引发剂用量对聚合物特性粘度的影响。结果表明:在油水体积比为1∶1.6、乳化剂用量为30%、单体用量为30%、阳离子度为60%即n(AM)∶n(DAC)为2∶3,引发剂用量为0.15%的条件下,得到的聚合产物粘度较大且具有良好的稳定性和溶解性。对产物进行了红外结构表征,并研究了产物的污泥脱水性能,获满意结果。     

阳离子聚丙烯酰胺微乳液的制备及其絮凝性能研究

以甲醛、二甲胺和丙烯酰胺为原料,通过Mannich反应首先合成阳离子单体N-(二甲氨基)甲基丙烯酰胺,然后用反相微乳液聚合制得不同阳离子度的阳离子聚丙烯酰胺乳液(CPAM).通过探讨反应过程的影响因素,确定了最佳的制备工艺,并对制成的产品进行了性能研究.当反应温度50℃,物质的量比n(丙烯酰胺)∶n(甲醛)∶n(二甲胺)=1∶1.2∶1,反应时间为2 h时,制备的阳离子单体可使乳液聚合的产品获得最佳的阳离子度.通过正交实验反映了单体质量分数、引发剂质量分数、油水相体积比以及反应温度对聚合反应的影响.结果表明,当单体质量分数为30%,引发剂质量分数为0.8%,油水相体积比1.2∶1,反应温度40℃时产品的絮凝效果最佳.在常温、酸性条件下,CPAM对硅藻土的絮凝效果良好.     

AA/AMPS接枝环氧树脂E-44的水性化改性研究

为改善环氧树脂E-44的水溶性,以丙烯酸(AA)和2-甲基-2-丙烯酰胺基-丙磺酸(AMPS)为接枝共聚的单体对环氧树脂进行水性化改性.研究了引发剂、不同单体及比例和反应条件对接枝共聚物水分散稳定性的影响并通过红外光谱对产物进行了表征.结果表明,以2.71wt%的BPO为引发剂、以体积比1∶1的无水乙醇-乙二醇单甲醚为混合溶剂,在接枝共聚反应温度110℃,下用质量比为1∶1的AA/AMPS对等质量的环氧树脂E-44进行改性,得到的改性环氧树脂水性化改性效果最好,乳液离心稳定性和贮存稳定性最高.     

PDMDAAC-AM共聚物的反相乳液聚合研究

研究了用二甲基二烯丙基氯化铵(DimethylDiallylAmmoniumChloride，DMDAAC)和丙烯酰胺(Acylamide，AM)为原料。以煤油为分散剂，在反相乳液环境中合成PDMDAAC-AM(Poly DMDAAC—AM)的方法．从反相乳液聚合的机理出发。研究了油水体积比、引发剂的用量、单体配比、引发温度和反应温度等因素对共聚产物的特性黏度和转化率的影响，确定了最佳反应条件．在DMDAAC／AM=2：8，油水比为3：7，采用过硫酸钾为引发剂，其用量为体系总质量的0．05％的条件下，采用逐步聚合的方法得到了固含量为45％，特性黏度为800．5cm^3／g，溶解迅速且絮凝效果好的产品．     

纤维素与丙烯酸在氯化锌水溶液中的均相接枝

以质量分数为65%的氯化锌水溶液为反应介质、过硫酸钾为引发剂,研究了微晶纤维素(MCC)与丙烯酸(AA)的均相接枝共聚反应,考察了引发剂用量、引发时间、接枝共聚时间、单体用量等因素对接枝率的影响,并用FT-IR、XRD和TGA分析了接枝前后微晶纤维素的特性.结果表明:当引发剂与MCC的质量比为1∶2、单体与MCC的质量比为5∶1、引发时间为10 min、接枝共聚时间为8 h、共聚温度为60℃时,接枝率达20.3%;随接枝时间的延长,接枝产物粒径呈减小趋势,电位呈增加趋势;接枝后的产物在1729cm-1处有CO的吸收峰,说明接枝上了丙烯酸单体;接枝后MCC的结晶度及热分解温度均降低.     

抗盐性AA-AMPS共聚分散剂的合成

以丙烯酸(AA)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为共聚单体,过硫酸铵为引发剂,异丙醇为链转移剂,采用水溶液聚合法,合成了AA-AMPS共聚物.研究了引发剂用量、链转移剂用量及聚合反应温度等因素对聚合产物黏均分子质量的影响.实验结果表明,在n(AA)∶n(AMPS)=96∶4,引发剂质量分数(基于两种单体)为2%～5%,链转移剂质量比(基于两种单体)为0.30～0.95,单体质量分数(基于反应体系)为40%,反应温度在85～100℃,反应时间3 h的条件下,合成出了黏均分子质量在3900～10 000范围内的AA-AMPS共聚物.最后对产物进行了红外光谱分析.     

磁性聚苯乙烯(Fe_3O_4/PS)微球合成的影响因素分析

以共沉淀法制备的Fe3O4纳米颗粒作为磁核,用聚乙二醇(PEG)为分散剂,过氧化苯甲酰(BPO)为引发剂,苯乙烯为单体,在乙醇/水混合溶剂中,采用分散聚合法制备出聚苯乙烯磁性高分子微球.研究聚合温度、Fe3O4用量、引发剂用量、分散剂用量以及乙醇/水比例等反应条件对聚合物磁性微球粒径和磁性能的影响,找出的最佳工艺参数为:单体用量为15 mL,Fe3O4用量为0.5 g,引发剂与单体的质量比为10∶1 000,醇水体积比为45/50,分散剂PEG用量为25 g,最佳反应温度为75℃.     

悬浮聚合法制备聚丙烯腈共聚物的工艺研究

以正庚烷和水混合反应介质,偶氮二异丁腈(AIBN)为引发剂,研究了丙烯腈(AN)与衣康酸(IA)、丙烯酸甲酯(MA)为共聚单体的自由基悬浮聚合反应.最佳的工艺条件为:单体浓度30%,AIBN占总单体质量比为0.01%,十二烷基硫酸钠(SLS)与水质量用量比0.024,油水质量比为8:33,反应时间11 h,转化率高为78.9%和粘均分子量为8.76×104,产品通过FTIR进行了确证.     

本体聚合法制备保塑-减缩型聚羧酸系减水剂

以丙烯醇聚氧乙烯醚(APEG)和二乙二醇单丁醚单马来酸酯(MADGBE)为原料,在本体聚合条件下合成聚羧酸系减水剂(PCE).研究了单体摩尔比、聚合温度以及引发剂的投料方式对产物性能的影响.试验结果表明,当MADGBE与APEG的摩尔比为3.5∶1,聚合温度为90℃,引发剂均分三份后分批加入所制备的聚羧酸系减水剂具有良好的混凝土坍落度保持性,且显著降低了混凝土的收缩率,但在一定程度上延长了混凝土的凝结时间.最后,利用红外光谱对产物分子结构进行表征,结果表明所得产物分子结构与预期相符.     

MA-AA-MAS三元共聚物的制备及其阻垢性能研究

以水为溶剂,过硫酸钾为引发剂,马来酸酐(MA)、丙烯酸(AA)和甲代烯丙基磺酸钠(MAS)为单体合成了三元共聚物.探讨了该共聚物转化率、平均分子质量、阻垢分散效果与单体配比、引发剂用量、反应温度、反应时间之间的关系.结果表明,当单体MA,AA,MAS物质的量比为3.0∶1.0∶0.6,引发剂质量分数为单体总量的14%,反应温度应控制在90℃,反应时间为4 h时,所制得的共聚物性能最佳,单体转化率为90.1%,对CaCO3和Ca3(PO4)2的阻垢率分别达到98.2%和92.1%.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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