水性涂料用聚氨酯／丙烯酸酯复合乳液合成技术的研究

大量研究表明,将聚氨酯和聚丙烯酸酯结合在一起得到的聚氨酯／丙烯酸酯复合乳液（PUA）可使涂膜获得更优异的性能,在水性涂料中有重要的应有价值．PUA复合乳液的合成方法对复合组分的相容性以及复合乳液乳胶膜的性能有重要的影响．本文综述了水性聚氨酯／丙烯酸酯复合乳液主要合成方法的研究状况,并对各种方法进行比较．     

复合膜用PUA黏合剂的合成与性能

以丙烯酸酯单体为原料,水性聚氨酯为种子乳液和高分子乳化荆,合成了核-壳结构的聚氨酯-丙烯酸酯复合乳液.采用傅里叶红外光谱表征了反应产物的结构.研究丙烯酸酯与聚氨酯质量比、丙烯酸酯软硬单体质量比对复合乳液性能、胶膜耐水性、热稳定性及180°剥离强度的影响.结果表明:随丙烯酸酯与聚氨酯质量比和丙烯酸酯硬单体质量的增加,复合乳液黏度减小,粒径增大,胶膜耐水性和热稳定性提高.当丙烯酸酯与聚氨酯质量比为2.0,丙烯酸酯软单体与硬单体质量比为75/25时,聚氨酯-丙烯酸酯复合乳液黏合荆对双向拉伸聚丙烯/铝箔的粘接强度优于国外样品.     

酮肼交联型聚氨酯-氟化聚丙烯酸酯乳液的制备

采用单体预乳化的乳液聚合工艺,利用丙烯酸酯单体、有机氟单体、双丙酮丙烯酰胺合成含有活性酮羰基的氟化丙烯酸酯乳液;然后同合成的含有酰肼基的聚氨酯乳液按一定的比例混合制备出酮肼交联型聚氨酯-氟化聚丙烯酸酯(FPUA)复合乳液.通过红外光谱、激光粒径分析、透射电镜、接触角和耐溶剂性、耐水性能检测等方法对FPUA复合乳液及成膜物的组成和结构进行了分析和表征,并对复合乳液的涂料印花性能进行了检测.     

水性聚氨酯-丙烯酸酯复合乳液的合成与表征

为开发高性能且环保的丙烯酸酯改性水性聚氨酯乳液,以甲苯二异氰酸酯、聚醚二元醇、二羟甲基丙酸（DMPA）和甲基丙烯酸甲酯为主要原料,采用原位乳液聚合法,先制得水性聚氨酯预聚物／乙烯基单体混合物,然后加入引发剂,经自由基乳液聚合得到聚氨酯一丙烯酸酯（PUA）复合乳液,并对影响复合乳液性能的因素进行了探讨．研究发现,PUA复合乳液的性能及外观与-NCO／-OH比（物质的量比,下同）、二羟甲基丙酸（DMPA）含量以及中和度等密切相关．当n（-NCO）：n（-OH）=1．3～1．4,-COOH质量分数在2．6％左右．中和度为90％～100％时,所得PUA复合乳液的外观好、性能佳．     

肼基封端聚氨酯乳液的制备及其对丙烯酸酯共聚物乳液粘合剂的改性

以聚酯二元醇、甲苯二异氰酸酯、二羟甲基丙酸(DMPA)、水合肼等为原料,制得了自乳化的肼基封端聚氨酯稳定乳液。以苯乙烯、丙烯酸乙酯、丙烯酸异辛酯、丙烯酸和双丙酮丙烯酰胺为单体,通过乳液聚合制得了含酮羰基丙烯酸酯共聚物乳液。将含肼基和酮羰基的两种乳液共混,所得复合乳液用作塑 塑复合粘合剂,使其在室温下发生酮肼交联反应以提高粘接性能。考察了预聚反应时间对预聚反应程度、不同DMPA含量和R-值(预聚体中n(—NCO)/n(—OH))对聚氨酯乳液性能以及两种乳液配比对胶膜凝胶含量、吸水率及180°剥离强度的影响,并比较了含肼基聚氨酯和小分子己二酰肼对丙烯酸酯共聚物乳液的改性效果。结果表明：当预聚反应210min、DMPA质量分数4.5%、R值小于1.5时,可制得稳定的聚氨酯乳液;随着共混乳液中肼基含量的增加,乳胶膜凝胶含量增大,吸水率增加,180°剥离强度降低;含肼基的聚氨酯对丙烯酸酯共聚物乳液的改性效果优于小分子己二酰肼的改性。     

含氟单体对聚氨酯-氟化丙烯酸酯复合乳液性能的影响

以甲基丙烯酸十二氟庚酯(DFMA)和丙烯酸酯为单体,以水性聚氨酯作种子乳液,通过单体滴加法和单体预乳化法两种不同的聚合工艺制备聚氨酯-氟化丙烯酸酯(FPUA)复合乳液.对FPUA胶膜的结构和性能进行了检测与表征,探讨了含氟单体、不同聚合工艺对FPUA复合乳液聚合稳定性及胶膜性能的影响.     

丙烯酸树脂交联改性水性聚氨酯乳液

文中利用肼基与酮羰基之间的脱水缩和反应制备了丙烯酸树脂交联改性水性聚氨酯乳液。探讨了肼基、酰胺基的含量对水性聚氨酯(PU)乳液、苯丙(PA)乳液性能的影响以及交联反应对漆膜性能的影响。实验结果表明,水性聚氨酯中加入肼基化合物提高了膜的拉伸强度,硬度及耐水性等性能,同时发现,肼基化合物的用量在不超过4%时水性聚氨酯乳液最稳定;酰胺化合物的用量对苯丙乳液也有较大影响,酰胺化合物在乳液中质量分数小于6%时,丙烯酸乳液的稳定性最好。丙烯酸树脂交联改性水性聚氨酯乳液,其拉伸强度、硬度等皆比改性前的聚氨酯、丙烯酸乳液要好,当酰胺基化合物与肼基化合物保持相同交联基团摩尔比时,得到乳液性能最好。     

聚氨酯／聚丙烯酸酯复合乳液的研制进展

概述聚氨酯-聚丙烯酸酯复合乳液的制备方法。特别对聚氨酯-聚丙烯酸酯复合乳液共聚法作了较为系统的介绍和讨论。     

甲基丙烯酸甲酯与水性聚氨酯的共聚反应

采用甲基丙烯酸甲酯(MMA)与水性聚氨酯乳液共聚制备聚氨酯-丙烯酸酯(PUA)复合乳液,研究了MMA添加量对PUA复合乳液的制备及涂膜性能的影响,并应用傅立叶红外光谱(FTIR)和凝胶渗透色谱测定反应产物的结构和相对分子质量．研究发现随MMA添加量增大,PUA复合乳液平均粒径增大,粘度减小,PUA树脂的相对分子质量增大,涂膜光泽度下降,机械性能变好,涂膜耐水、耐乙醇性增加．合适的MMA添加量为体系总固体质量的20％～30％．     

水性丙烯酸酯/聚氨酯复合乳液的合成及性能研究

以二羟甲基丙酸（DMPA）、双丙酮丙烯酰胺（DAAM）为功能性单体,以丙烯酸酯类为溶剂合成了水性丙烯酸酯聚氨酯(PUA)复合乳液,成功的解决了以丙酮为溶剂制备水性聚氨酯造成的VOC含量高、工艺复杂、浪费能源的问题。通过红外(FT-IR)、透射电镜(TEM)等测试手段及吸水率、耐溶剂性、硬度、凝胶含量的测定,考察了丙烯酸酯聚氨酯复合乳液（PUA）及其涂膜的结构与性能,结果表明PUA复合乳液涂膜硬度达到3H,凝胶含量可达到84.3%,且耐水性、耐溶剂性得到明显提高。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has