电凝聚净水技术在工业上的应用

一、绪言近年来电化学净水技术愈来愈多地引起了研究人员的注意,其中之一就是电凝聚法。苏联、日本、波兰、英国、美国等都进行电凝聚法净水技术的研究,其中以苏联研究得最早最多,并进行了大量的实验性研究,到1977～1979年电凝聚法得到了广泛的运用。图1为电化学净水技术的代表性实例的分类。电凝聚法是一种既有物理作用又有化学作用的电化学净水技术。它采用可溶性金属为阳极(如Al和Fe),在直流电场的作用下,阳极反应为金属铝的溶解(以金属铝为电极)。     

乳液聚合丁苯橡胶凝聚机理在实际操作中的应用

以中国石油吉林石化公司丁苯橡胶装置凝聚岗位工艺为研究对象,通过工艺流程、使用助剂、工艺参数的对比,深入研究凝聚作用机理,分析实际生产过程中影响凝聚作用的关键因素,提出解决问题的方法,提高装置凝聚效果,改善成品胶质量。     

溶液聚合橡胶凝聚节能理论

通过分析溶液聚合橡胶凝聚过程中水蒸气的作用，利用非均相水蒸气蒸馏原理，对凝聚工艺条件的优化进行了研究，结果表明，凝聚釜越接近气－液平衡态操作越节能，同时给出了凝聚过程蒸汽消耗量的计算方法。     

电凝聚对微污染水净化的研究

通过改变电流密度、通电时间、沉淀时间等因素,采用电凝聚法对微污染水中的细菌、浊度、CODMn的去除进行了试验研究。得出电凝聚通过电解氧化、凝聚和气浮联合作用,对微污染水中的浊度、细菌能有效地去除,同时对CODMn具有很强的降解作用。     

超声波作用下具有中性浮升力的微粒凝聚分离

针对超声波作用下悬浮液中具有中性浮升力的微小颗粒 (以下简称微粒 )凝聚分离过程中凝聚过程参数以及声学参数对凝聚过程参数的影响进行了分析研究。同时 ,利用数值模拟预测了微粒的凝聚过程参数 ,并且与解析解进行了比较 ,表明数值计算可靠 ,并且需要作为解析解的补充。     

ACR胶乳凝聚过程的研究

以丙烯酸酯（ACR）聚合物胶乳凝聚过程中粒径的变化表征凝聚效果，探讨在凝聚剂作用下的凝聚机理，研究凝聚剂、凝聚温度、搅拌转速、搅拌时间和胶乳固含量等条件对凝聚过程的影响规律，为优化工艺条件，制备大小均匀、形态较为规整的凝聚颗粒，实现ACR胶乳凝聚的工业化提供基础。     

MBS树脂合成技术的中试研究(Ⅲ)MBS胶乳的凝聚

阐述了聚合物乳液的凝聚机理和MBS接枝胶乳的凝聚工艺,在MBS胶乳凝聚小试研究和MBS接枝胶乳中试研究的基础上进行了MBS接枝胶乳凝聚的中试研究,着重研究了凝聚剂种类、用量和加料方式以及凝聚温度、水胶比等对MBS粉料堆密度和粒度分布的影响,确定了MBS胶乳的凝聚工艺,为5 000 t/a MBS树脂生产装置提供了设计依据.     

废水处理中电凝聚气浮技术的研究现状与进展

简要介绍了电凝聚气浮技术的作用机理及其应用领域,综述了电凝聚气浮技术处理效率的影响因素、与其它处理工艺的结合以及处理装置等几方面的研究进展,指出了该技术存在的问题及研究方向     

低冲击条件下凝聚炸药延迟起爆现象的研究进展

描述了凝聚炸药在低强度冲击作用下的延迟现象XTD介绍并分析研究XDT现象的试验和数值模拟方法，提出了XDT研究的发展方向。     

超声波对电凝聚-膜滤组合工艺除氟的影响研究

针对电凝聚-膜滤组合工艺除氟过程中出现的极板钝化以及滤膜污染问题,以除氟为对象,研究了超声电凝聚工艺除氟和超声电凝聚.膜滤组合工艺除氟,探讨了超声波对于除氟效果、极板钝化和膜污染的影响.研究发现,超声波能延缓极板钝化,提高除氟效率.在一定范围内,功率越大,效果越好;而不适宜的超声条件对于延缓膜污染,增大产水量,作用不明显.     

Dispersion Polymerization of Styrene by Initiation Within Monomer Phase with Lauroyl Peroxide

Dispersion polymerization kinetics of styrene was investigated in this study. A monomer phase soluble initiator, namely lauroyl peroxide, and a water phase soluble emulsifier, namely sodium dodecyl sulfate, were used. the polymerizations were carried out in a magnetic drive, sealed, cylindrical polymerization reactor, in nitrogen atmosphere. Two different fatty alcohols, cetyl and lauryl alcohols, were tried as particle size increasing agents. the effects of initiator, emulsifier concentrations, monomer/water ratio, and the weight ratio of particle size increasing agent to emulsifier on the total monomer conversion, average size, and size distribution of the large latex particles were studied. the agglomeration conditions were tested by changing the polymerization temperature, initiator, and emulsifier concentrations. the results indicated that the polymerization rate and the average size of the latex increased with increasing emulsifier concentration. the average size of the latex was also increased with increasing initiator concentration. the use of cetyl alcohol in the presence of emulsifier resulted in an appreciable increase in the polymerization rate and in the average size of the latex. the effect of fatty alcohols on the polymerization rate in the dispersion polymerization system was completely different than that in the swollen emulsion polymerization. the agglomeration of the large latex particles was increased with decreasing emulsifier and increasing initiator concentrations.     

MBS树脂合成技术的中试研究(Ⅰ)SBR胶乳的合成

从单体配比和SBR胶乳粒径对PVC／MBS合金抗冲性能和透光率的影响方面详细阐述了MBS接枝用SBR胶乳“粒子设计”的依据;在小试配方的基础上进行了SBR胶乳的中试试验,着重研究了SBR胶乳聚合过程和乳化剂用量、反应温度及搅拌速度等对SBR胶乳粒径和体系稳定性的影响,并将SBR胶乳中试结果与小试结果进行了对比,确定了中试配方和工艺条件,为5000t／aMBS生产装置的设计提供了依据。     

核壳型调金油乳液的制备及应用研究

采用单体预乳化结合种子聚合法合成具有核壳结构的调金油乳液。对乳胶粒核壳结构、功能单体甲基丙烯酸（MAA）的用量、交联单体N-羟甲基丙烯酰胺（N—MA）的用量及配墨乳液用量对银墨性能的影响进行了讨论。结果表明：MAA所占单体总量质量比为3％、N—MA为3％时所制备的核壳结构的调金油乳液配墨性能最佳,银墨的最佳物料质量配比为异丙醇15％、铝银浆15％、调金油乳液70％。     

自交联丙烯酸酯类反应性微凝胶乳液的聚合稳定性

采用半连续种子乳液聚合方法合成了自交联丙烯酸酯类反应性微凝胶乳液,研究了聚合工艺条件对聚合反应稳定性的影响。结果表明,当增大乳化剂SDS/OP-10的用量或加快预乳化单体的滴加速度时,聚合反应稳定性增加;随着引发剂过硫酸钾(KPS)、交联剂三羟甲基丙烷三丙烯酸酯(TMPTMA)和单体用量的增加,微凝胶颗粒分子间的交联反应增强,聚合反应稳定性下降。加入功能性单体甲基丙烯酸(MAA)和丙烯酸(AA)都能使聚合反应的稳定性增强,随着MAA用量的增加,聚合反应稳定性呈先增强后下降的趋势。当所加入的SDS/OP-10质量分数为3%~4%、KPS为0.4%~0.6%、TMPTMA为1%~3%、MAA不超过3%及单体为30%~40%,预乳化单体滴加速率为20~30 mL/h时,聚合过程的稳定性最好。由傅里叶变换红外光谱分析可知,通过优化聚合条件,得到了含有官能性环氧基和羧基的丙烯酸酯类反应性微凝胶乳液。     

用于可再分散乳胶粉的阳离子苯丙乳液的合成

采用种子乳液聚合法,以十六烷基三甲基溴化铵(CTAB)为乳化剂,偶氮二异丁眯盐酸盐(AIBA)为引发剂,引入亲水性阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)及功能性单体丙烯酰胺(AM)〔m(DMC)∶m(AM)=1∶1〕来制备用于可再分散乳胶粉的阳离子苯丙乳液。探讨了聚合反应温度、乳化剂用量、引发剂用量、种子单体用量、阳离子单体用量等对乳液及可再分散乳胶粉性能的影响。确定最佳配方和工艺条件为:聚合反应温度为(80±2)℃、DMC添加量为2%(以主要聚合单体质量计,下同)、CTAB用量为2%(以单体总质量计,下同)、AIBA用量为0.53%(以单体总质量计,下同)、种子单体用量为10.0%(以单体总质量计,下同)。在该工艺条件下,合成的阳离子苯丙乳液粒径大小和分布适中、性能稳定,由其所制得的可再分散乳胶粉含水率低、平均粒径小、再分散性优良。     

Stability of carboxylated poly(butyl acrylate) latices during semibatch emulsion polymerization

The stability of latex particles in the semibatch emulsion polymerization of butyl acrylate (BA) in the presence of 0–10% acrylic acid (AA) was investigated. The amount of coagulum (i.e., large flocs caused by intensive coagulation) can be greatly reduced by an increase in the concentration of sodium lauryl sulfate (SLS) in the monomer emulsion feed. On the other hand, increasing the concentration of SLS in the initial reactor charge can result in an increase in the percentage of the particle volume change (i.e., a measure of the degree of limited flocculation) later in the process. Both the scrap and percentage of the particle volume change increase with an increase in the electrolyte concentration. Both the coagulation and secondary nucleation process can result in a significant deviation from the Novak model. Experimental data also show that latex particles comprising pure BA can lose their stability rapidly at higher total solids content because of the crowding effect. Incorporation of only 5% AA into the emulsion polymers greatly improves the latex stability. © 1996 John Wiley & Sons, Inc.     

Preparation and characterization of waterborne epoxy latexes and epoxy/(silica sol) composites

A series of waterborne epoxy latexes was synthesized, and epoxy/(silica sol) composite latexes were prepared. The effects of functional monomer methacrylic acid (MAA) and silica sol on the latex particle size, morphology, and stability were investigated. With increasing amounts of MAA, the conversion rate increased, the particle size reduced, and the viscosity of the epoxy latexes increased. The epoxy latexes had storage stability and could be stored at room temperature for more than 6 months with a solid content variation of less than 1%. For the (silica sol)‐modified waterborne epoxy latexes, the effects of preparation techniques and silica sol content on the latexes and latex films were investigated. When the silica sol content increased, the particle size of the composite latexes decreased. The morphology investigation showed that when the silica sol content increased, the uneven surface level of the latex films was increased. The increase of elemental silica on the surface was in accord with the improvement of the water resistance of the composite latex films. The heat resistance of these films was improved as well, and their overall performance was better than that of the epoxy latex films. J. VINYL ADDIT. TECHNOL., 20:57–64, 2014. © 2014 Society of Plastics Engineers     

水溶性单体类型对BA-MMA-St微皂乳液聚合的影响

通过与水溶性单体、甲基丙烯酸（MAA）、丙烯酸（AA）、N-羟甲基丙烯酰胺（N-MA）、丙烯酰胺（AM）共聚，实现了BA-MMA-St的微皂乳液聚合。考察了水溶性单体（羧酸类单体、非离子水溶性单体）对微皂乳液聚合稳定性和化学稳定性的影响。实验结果表明：为了使水溶性单体键合在乳胶粒表面，实现乳胶粒的稳定化，其亲水性参数I／O应为3～5，水溶性单体还必须具有良好的聚合稳定性及与主单体良好的共聚性。     

Morphology of poly(isoprene-co-styrene-co-methacrylic acid) latex prepared by two-stage seeded emulsion polymerization

Heterogeneous latexes were prepared by a two-stage seeded emulsion polymerization process at 80°C using potassium persulfate as the initiator and sodium dodecyl sulfate as the emulsifier. Poly(styrene-co-methacrylic acid) latexes containing varying amounts of methacrylic acid (MAA) were used as seeds. The second-stage polymer was poly(isoprene-co-styrene-co-methacrylic acid). By using different methods for the addition of the MAA and by varying the amount of MAA, the hydrophilicity of the polymer phases could be controlled. The morphologies and size distributions of the latex particles were examined by transmission electron microscopy. The latexes were in all cases unimodal, and had narrow particle size distributions. The particles displayed different morphologies depending on the polymerization conditions and monomer composition. The hydrophilic properties of the two phases in combination with the internal particle viscosity and crosslinking of the second phase during polymerization were found to be the major factors influencing the particle morphology. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1543–1555, 1997     

中空聚合物微球的制备——种子及核乳胶粒的制备

为了制得具有中空结构的聚合物微球,首先以十二烷基苯磺酸钠(SDBS)为乳化剂,在其用量低于CMC的条件下,进行甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)和丙烯酸丁酯(BA)的乳液聚合,制备了带羧基的种子乳胶粒.然后采用MMA、MAA和二乙烯基苯为单体进行种子乳液聚合,制备了轻度交联的带羧基的核乳胶粒.该核乳胶粒经过核-壳乳液聚合和适当的碱处理工艺就可成为具有中空结构的聚合物微球.采用粒度仪测定了乳胶粒的直径及其分布,采用TEM对乳胶粒结构形态进行了表征.研究了种子及核乳胶粒制备过程中单体加料方式、乳化剂用量及羧基单体种类等因素对聚合稳定性、乳胶粒直径及其分布以及最终的中空聚合物微球结构形态的影响,确定了制备种子及核乳胶粒的最佳工艺条件.在制备种子阶段,SDBS用量为单体总量的0.5%,采用一次性加入单体的进料工艺;在核乳胶粒制备阶段,以MAA为羧基单体,所有单体采用"饥饿式"加料,半连续补加乳化剂并使乳化剂用量为核单体总量的0.15%时可保持聚合稳定性并保证无新乳胶粒生成.