聚乙烯醇醇解度快速测定法

介绍聚乙烯醇树脂醇解度≤９７％（ｍｏｌ／ｍｏｌ）的快速测定法。     

聚乙烯醇醇解度的影响因素及其控制

根据聚乙烯醇生产的醇解反应机理及影响醇解反应的因素,在理论、实践的基础上详细阐述了实际生产中如何控制不同品种聚乙烯醇的醇解度。     

超低醇解度聚乙烯醇的开发和应用

叙述了超低醇解度聚乙烯醇的特性、发展现状、开发意义以及用途，介绍了超低醇解度聚乙烯醇的醇解工艺以及低于60(mol)％的超低醇解度“水不溶性”聚乙烯醇在氯乙烯悬浮聚合分散剂方面的应用。     

聚乙烯醇树脂醇解度测定方法的改进

本文就聚乙烯醇树脂醇解度测定方法进行了研究,结合大量的实验,找出了影响聚乙烯醇树脂醇解度测定结果准确度的主要因素,并对聚乙烯醇树脂醇解度测定方法进行了改进.改进后的方法更加科学合理,测定结果更加准确可靠,有利于指导生产和减少用户质量异议.     

测定聚乙烯醇醇解度的注意事项及其分析

简要介绍了测定聚乙烯醇醇解度的原理及方法,并对测定过程中的注意事项及原因作了进一步的分析.     

聚乙烯醇生产醇解度的控制

本文分析、介绍了聚乙烯醇生产的醇解机理、醇解影响因素、醇解工序工艺流程．对醇解度控制的主要思路，在理论、实践及实验室研究上作了分析和探索。     

超低醇解度聚乙烯醇聚合度的测定

介绍了超低醇解度聚乙烯醇聚合度的测定方法,讨论了处理剂、处理温度、样品干量、甲醇碱、处理时间等对测定方法的影响。该方法重现性好。     

聚羧酸减水剂的合成及其分散性能

以甲氧基聚乙二醇甲基丙烯酸酯(PMA45)、甲基丙烯酸(MAA)、甲基丙烯磺酸钠(MAS)为单体,以过硫酸铵(APS)为引发剂,采用水溶液自由基聚合法合成了聚羧酸高效减水剂(PC),分析了合成过程中不同单体摩尔比、相对分子质量(简称分子量,以下同)大小对其分散性能的影响。结果表明,单体和引发剂的用量同时影响聚羧酸减水剂分子量和分散性能;当n(MAS)∶n(MAA)∶n(PMA45)=0.5∶3.75∶1,APS用量为单体总质量的0.4%时,产品聚羧酸特性黏度为45.09 mL/g;当水灰质量比为0.25,聚羧酸减水剂掺量为水泥质量的0.2%时,净浆初始流动度达到最大269 mm,30 m in经时流动度为281 mm。     

部分醇解的聚乙烯醇纤维结构性能初探

对较低聚合度的聚醋酸乙烯进行醇解,得到一系列不同醇解度的聚乙烯醇,经纺丝拉伸后,得到不同醇解度、不同拉伸倍数的聚乙烯醇纤维。用FT-IR、DSC和强力仪等研究了醇解度和拉伸倍数对纤维结构性能的影响。结果表明,部分醇解的聚乙烯醇有利于降低拉伸中的氢键作用,提高易拉伸性。     

Polyaniline with high crystallinity degree: Synthesis,structure, and electrochemical properties

Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE‐SEM), Fourier transforms infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). FE‐SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI‐2 < PANI‐6 < PANI‐10. XPS measurements displayed that PANI polymerized at 6 mA cm^?2 (PANI‐6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI‐6 possessed highest crystallinity degree (X_cr) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI‐6 possessed greater discharge capacity and better reversibility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40827.     

Correlation between surface tension and physical paint properties

Surface tension is a parameter of decisive importance for characterizing painted and unpainted surfaces related to wetting and adhesion phenomena. Measurements of the surface tension of solids by means of an automatic contact angle measurement device are presented. The theoretical evaluations provide for a separation of the surface tension into polar and disperse components. In addition, this paper briefly touches on other more far-reaching approaches (acid/base) and discusses a method for the determination of the dynamic surface tension of liquids.     

高聚合度PVAc醇解工艺研究

高聚合度的聚醋酸乙烯酯醇解制备聚乙烯醇,由于其相对分子质量较大,所以研究其醇解工艺显得尤为必要.就影响醇解工艺的因素,如醇解温度、醇解时间、催化剂浓度等进行了探讨,得出了高聚合度PVAc醇解最佳工艺.     

阴/阳离子表面活性剂复配体系的物化性能--不同乙氧基化数对溶解性及表面张力的影响

研究了十二烷基甲基聚氧乙烯氯化铵与脂肪醇聚氧乙烯醚硫酸盐复配体系在不同乙氧基化数的溶解性、表面张力及临界胶束浓度。复配体系的溶解性随乙氧基化数的增加而增加，乙氧基化数为2的阳离子与乙氧基化数为2、3的阴离子复配。在较大的浓度范围内可以在水中形成透明的均匀溶液；乙氧基化数为5的阳离子与乙氧基化数为2、3的阴离子复配。在活性物质量分数为25％以下时完全透明。复配体系的临界胶束浓度(cmc)及其表面张力(rcmc)较单一组分低得多。且表面活性随乙氧基化数增加而下降。未经提纯的阴、阳离子表面活性剂，复配后其r—c曲线中最低值现象明显减弱至消失。     

低聚缩水甘油苯基醚磺酸钠的合成及动态表面张力

通过缩水甘油苯基醚低聚物的磺化反应,合成了一种新型磺酸聚醚型高分子表面活性剂——低聚缩水甘油苯基醚磺酸钠(SPPGE),并用红外、核磁等对产物结构进行了详细表征。同时,测定了不同质量浓度、不同无机盐含量SPPGE水溶液的动态表面张力(DST),并用Rosen经验方程和Word—Tordai方程对DST进行了分析。结果表明：SPPGE溶液浓度越高,动态表面活性越高,DST达到界平衡越快,DST曲线越低;在研究的浓度范围内,吸附初期属扩散控制吸附,后期属混合动力吸附,且浓度越高,吸附势垒εa越大,有效扩散系数Deff小;对同一浓度溶液,添加电解质使DST曲线下降,吸附机理不变,但后期吸附势垒εa增大,有效扩散系数Deff减小。     

Synthesis,characterization, and surface properties of phenylalanine-glycerol ether surfactants

A novel homologous series of 1-N-l-phenylalanine-glycerol ether surfactants was synthesized in satisfactory yields via reaction of epichlorohydrin with aliphatic alcohols with alkyl chains of 10–15 carbon atoms. Structural assignment of the new compounds was made on the basis of elemental analysis and spectroscopic data. Critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m (pC₂₀), and the interfacial area occupied by the surfactant molecules (A_min) were determined from aqueous surface tension measurements using the Wilhelmy plate technique.     

Synthesis, characterization, and surface properties of sulfoxylated methyl esters

Sulfoxidation of fatty methyl esters with SO₂, O₂, and ultraviolet light of appropriate wavelength has led to a synthesis of sodium methyl ester sulfonates known as Φ-MES. The designation of Φ refers to the random positioning of SO₃ in the alkyl chain. This investigation describes for the first time the operating conditions necessary to produce these new anionic surfactants as well as the analytical methods used in their isolation, analysis, identification. Some surface properties are discussed as well.     

尿素醇解法合成碳酸乙烯酯

在干燥碱式碳酸锌催化剂的作用下,以尿素和乙二醇（EG）为原料合成碳酸乙烯酯（EC）。重点考察了催化剂用量、原料配比、反应温度、反应时间对反应结果的影响。并通过GC-MS、FTIR和XRD分析,初步探索了反应机理以及碱式碳酸锌的作用机理。结果表明：当催化剂用量为尿素质量的6%,原料配比n（EG）∶n（尿素）=1∶1,反应温度160℃,反应时间3h,反应压力为0.01MPa时,碳酸乙烯酯收率达到91.64%。尿素和乙二醇合成碳酸乙烯酯的反应中,尿素首先分解生成异氰酸,异氰酸再与乙二醇反应生成中间产物2-羟乙基氨基甲酸酯（2-HEC）,最后2-羟乙基氨基甲酸酯脱氨环化生成碳酸乙烯酯。所用碱式碳酸锌催化剂中存在Zn₄CO₃（OH）₆·H₂O和ZnO两种晶相,且以ZnO为主活性组分,两种晶相的协同作用提高了反应收率。