苯乙烯-co-N-苯基马来酰亚胺无规共聚物的合成与性能

以过氧化苯甲酰为引发剂,环己酮为溶剂,用半连续溶液聚合法合成了苯乙烯-co-N-苯基马来酰亚胺无规共聚物.通过调节单体投料比,制得含N-苯基马来酰亚胺质量分数为17%~55%之间的二元共聚物.采用FTIR、元素分析、13CNMR技术对共聚物的化学组成、链序列结构进行了测试表征.证明该共聚物链序列结构无规、化学组成均一,这种结构特征将大大提高其与被改性的基体树脂的相容性.此外,用DSC,TGA对共聚物的热性能进行研究,得出共聚物组成中N-苯基马来酰亚胺的含量与其耐热性及热稳定性的规律曲线.随着N-苯基马来酰亚胺含量的增加,共聚物耐热性和热稳定性均明显提高.所以该共聚物是一种理想的树脂耐热改性剂.     

AMS/AN/MMA三元共聚物的合成及其改性CPVC的研究

文章采用乳液聚合法合成了α-甲基苯乙烯/丙烯腈/甲基丙烯酸甲酯(AMS/AN/MMA)三元共聚物,用FT-IR和DSC对共聚物组成及其与CPVC相容性进行表征,并研究了合成工艺条件与单体配比对转化率的影响和三元共聚物与CPVC共混物的力学性能及加工性能。结果表明,该三元共聚物与CPVC的相容性良好;添加该三元共聚物对CPVC的加工性能有显著改进,且随共聚物中AMS质量分数增加,共混物的Vi-cat软化温度有所提高。     

热固性丙烯酸酯树脂的工艺概述

热固性丙烯酸酯树脂具有很好的耐紫外线优良性能,它广泛地用作塑料、涂料等工业生产的原材料,和热塑性丙烯酸酯树脂一样,大都以丙烯酸酯、甲基丙烯酸酯和其它乙烯系单体构成共聚物。 一、热固性丙烯酸酯树脂的性能 热固性丙烯酸酯树脂是通过树脂分子侧链上的活性宫能团与其它树脂产生交联反应而成。热固性树脂分子量通常略低于热塑性树脂,以获取不挥发份含量高的树脂溶液。     

豆油-苯乙烯共聚物的悬浮制备

采用悬浮聚合法将豆油与苯乙烯进行自由基共聚,制备支化和部分交联的聚合材料。结果表明,豆油与苯乙烯发生了共聚,聚合物中甘油酯基最高摩尔分数达到0.81%,豆油单元的质量分数达到6.50%。聚合温度85.0℃,反应时间4.0h,反应物中悬浮剂（聚乙烯醇）的质量分数0.15%,反应物中豆油的质量分数在10%时,共聚物的分子量达到最大值。共聚物中甘油酯基的含量随着反应物豆油含量的增加而增加。当反应物豆油的质量分数为10%时,凝胶的质量分数达到最大值3.70%。     

丁苯树脂的合成及其玻璃纤维增强塑料的研究

本文研究了以丁二烯和苯乙烯为单体原料,用阴离子溶液聚合法合成全碳氢元素组成的热固性树脂。该树脂具有外双健,可与各种乙烯基单体进一步共聚形成一系列热固性树脂。同时研究了树脂结构,影响固化的因素,和用过氧化物复合引发剂的固化特性,以及用偶联剂以增强树脂与玻璃纤维界面之间的粘结性能,采用接触成型法制备热固性丁苯树脂玻璃纤维增强塑料(简称丁苯玻璃钢),该树脂及其玻璃钢具有优良的机械性能、介电性能和耐水性能。     

一种高折光指数聚合物透明树脂的合成与性质

将具有高折光指数的硫和苯环等基团引入含C=C化 合物的分子结构中制备了单体甲基丙烯酸苯硫酚酯（PTMA）, 并利用 FTIR,¹H NMR和HPLC等技术对其结构进行表征. 将PTMA作为单体与苯乙烯进行共聚, 制备得到含硫透明光学树脂. 对其性能测试结果表明, 共聚树脂具有较高的可见光透光率, 而且随着PTMA质量分数的增加, 树脂的折光指数和密度线性增大, 冲击强度提高.     

一种新型丁二烯和苯乙烯嵌段共聚物的结构表征

采用具有f 轨道的稀土金属催化剂进行丁二烯(Bd)与苯乙烯(St)嵌段共聚得到丁苯共聚物。利用FTIR ,¹H NMR和¹³C-NMR和TEM分别对萃取均聚物后的共聚物进行微观结构、共聚物组成和微观形态的表征,利用GPC双检测(RI,UV)表征共聚物的相对分子质量、相对分子质量分布以及组成分布。实验结果表明:该共聚物为丁二烯与苯乙烯的嵌段共聚物,丁二烯结构单元中顺-1,4摩尔分数为97.0%,苯乙烯结合量为21.8% (摩尔分数)。共聚物中聚丁二烯(PB)链段与聚苯乙烯 (PS)链段形成了微观相分离结构。     

菜籽油基单甘油酯马来酸单酯与苯乙烯共聚条件的探讨

随着石油资源的日益枯竭和环境污染问题的日趋严重,植物油作为一种可再生的绿色生物基资源,以其产量巨大、可储存和碳循环等优点引起全球的广泛关注.本课题采用菜籽油在一定条件下先后与甘油(glycerin)和马来酸酐(MA)反应生成菜籽油基单甘油酯马来酸单酯(ROMG-MA),然后与苯乙烯发生共聚合反应,转化为热固性树脂.讨论分析了各个反应条件对产物总转化率的影响,得出ROMG-MA与苯乙烯共聚合反应的适宜条件为:ROMG-MA质量分数50%、BPO的质量分数5%、苯乙烯的质量分数45%、反应温度90℃,反应时间1.0h.     

溶液聚合法制备交联聚苯乙烯磺酸钠

以N-甲基吡咯烷酮(NMP)为溶剂,过氧化苯甲酰(BPO)引发苯乙烯(St)、二乙烯苯(DVB)、苯乙烯磺酸钠(NaSS)共聚合制备交联聚苯乙烯磺酸钠,并用红外光谱(FTIR)和热分析(DSC)对共聚物进行了表征.研究了反应条件对共聚物中苯乙烯磺酸钠含量的影响.结果发现:聚合反应时间为10 h温度90℃时,共聚物中苯乙烯磺酸钠的含量最接近理论值.DSC结果表明磺化聚苯乙烯其玻璃化转变温度(112℃)高于聚苯乙烯(104℃),但是磺化度进一步增加却观察不到明显的玻璃化转变.通过测定共聚物在水中的电导率,发现共聚物中苯乙烯磺酸钠的摩尔分数为7.81%时,导电率可达到0.32×10-2S/cm,苯乙烯磺酸钠摩尔分数继续增大对共聚物导电率的影响很小.     

苯乙烯—马来酸酐共聚探讨

苯乙烯(S)和马来酸酐(MA)自由基引发共聚反应,生成共聚物SMA,是典型的交替共聚。本文介绍了在40t/a的苯乙烯类本体聚合装置试验生产SMA的流程,探讨了影响SMA本体引发连续共聚合工艺的因素。同时,通过对生成物SMA的性能测试,分析得出苯乙烯—马来酸酐共聚物SMA的耐热性明显高于苯乙烯单体均聚物聚苯乙烯(PS),使得苯乙烯类树脂在耐热性方面扩大了使用范围。     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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