聚羧酸系列分散剂在农药水乳剂中的应用

采用清洁的水溶液聚合工艺,以丙烯酸、马来酸和功能单体为主要原料,合成了适宜结构的聚羧酸系列农药分散剂,考察和评价了其对水乳剂(EW)的配伍性及稳定性,并进行了田间药效验证试验,结果表明,其性能达到国内外同类产品水平,具有较好的推广应用价值.     

Synthesis,characterization, and evaluation of polyisobutylene‐based imido‐amine‐type dispersants containing exclusively non‐nucleophilic nitrogen

Lubricating oils for gasoline and diesel engines are formulated to include amphiphilic dispersants for soot particle stabilization and prevention of particle aggregation. Primary and secondary amines used within the polar group of traditional dispersants provide basic nitrogen, which is able to neutralize acidic by‐products from combustion and does not contribute to sulfated ash. However, these active‐hydrogen‐containing amines present significant problems for fluoroelastomer seals and metals in terms of degradation and corrosion. Polyisobutylene (PIB)‐based dispersants containing only tertiary amines, intended to remediate these problems, were synthesized from primary‐bromide‐terminated PIB, 1‐(2‐aminoethyl)piperazine, and an anhydride such as phthalic anhydride. Intermediates and final dispersant molecules were characterized by NMR, GPC, TGA, and MALDI‐TOF MS. Using Langmuir adsorption studies with carbon black as a surrogate for soot, a direct dependence on the affinity for adsorption of the dispersant with respect to the number of phenyl rings present was identified. Performance testing revealed increased compatibility of the dispersants, including limited degradation of seals and corrosion of metals, while retaining total base number. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1657–1675     

Using of Modified Plastic Waste Based on Poly(ethylene‐co‐acrylic acid) Grafts to Solve Transportation Problem of Petroleum Crude Oil

Polyethylene acrylic acid copolymer (PEAA) was modified with different types of alkanols and hydroxybenzoic acids to produce three types of esterified grafts. The molecular structures of the synthesized dispersants were performed using ¹H NMR analysis. The molecular weights of the synthesized dispersants were determined by GPC technique. The activity of PEAA derivatives as asphaltene stabilizer in the crude oil was evaluated by means of flocculation measurements. The effect of asphaltenes on the rheological behavior of highly asphaltenic crude oils was studied to evaluate the transportation parameters of crude oils. The rheological properties were measured at different temperature ranges of 5°C to 25°C in presence and absence of PEAA additives. It was observed that the PEAA having side chain lengths below C₁₆ show non‐Newtonian pseudoplastic relationships at temperatures from 25°C to 5°C. While, PEAA additives having side chain lengths equal or above C₁₆ show Newtonian relationship even at low temperature (5°C) for all tested crude oils.     

分散剂对YAG粉末形貌和性能的影响

以硝酸铝［Al(NO3)39H2O］和硝酸钇［Y(NO3)36H2O］为原料,碳酸氢铵［NH4HCO3］为沉淀剂,PEG400,PEG800和PEG1000等为分散剂,采用正向共沉淀法合成了钇铝石榴石（YAG）前驱体粉末。并用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、粒度测试仪等分析了粉末的形貌和性能。结果表明,分散剂的加入,减少了粉末的团聚现象,而且由PEG400,PEG800分散剂制备的先驱体粉末经1200 ℃煅烧60 min后均能形成纯度较高的YAG相,但PEG1000样品粒度更细,比表面积为1748.78 m2/kg,中位径为1.42 m,而前者所得粉末的比表面积分别为29.39和128.60 m2/kg,中位径分别为196.14和20.55 m。     

水煤浆分散体系中阴离子型分散剂的吸附特性和降粘效应

研究了一种阴离子型分散剂在煤表面的吸附特性和其产生的降粘效应，以及它们与煤表面结构性质间的关系。结果表明，阴离子型分散剂的吸附性能和降粘效应受煤表面含氧官能团尤其是羧基官能团的显著制约。低温热处理（２００￣３３０℃）使年轻煤表面硫水化作用显著增强，从而显著地提高了分散剂在煤表面的吸附性能及其对水煤浆产生的降粘效应，因此，年轻煤的成浆性得到大幅度改善。     

不同分散剂对水热法制备氧化锆颗粒分散性的影响

研究利用氯氧化锆和氨水作为原料水热法制备氧化锆微粉的方法。对分散剂种类及分散剂量对氧化锆微粉分散性影响进行了讨论,应用扫描电子显微镜和粒度分布仪对获得的氧化锆粉体进行分析。结果显示：加入聚乙二醇6000时,二氧化锆在水中分散性最好;采用1.150%聚乙二醇作为分散剂时,可获得在水中分散性较好的氧化锆粉末;相同质量分数的分散剂,分散效果较好的排序是：有机高聚物〉无机电解质〉阴离子表面活性剂〉有机物异丙醇。     

纳米CuO在水介质中分散性能的实验研究

为了解纳米CuO在水介质中分散性能,以纳米材料常用的十二烷基苯磺酸钠、十六烷基三甲基溴化铵和聚乙二醇为分散剂,采用磁力搅拌和超声振荡与添加分散剂相结合的方法制备纳米CuO悬浮液,研究了磁力搅拌和超声振荡以及分散剂型与剂量对纳米CuO悬浮液分散性能的影响。结果表明:磁力搅拌和超声振荡对于纳米CuO粒子在水介质中的分散具有一定的效果,但不能明显提高悬浮液的分散稳定性,而添加一定剂量的分散剂对悬浮液的分散稳定性起着至关重要的作用。磁力搅拌30 min和超声振荡60 min与添加质量分数为0.05%的十六烷基三甲基溴化铵,对0.2%的纳米CuO悬浮液的分散稳定性效果最好。     

Dispersant Molecules with Functional Catechol Groups for Supercapacitor Fabrication

Cathodes for supercapacitors with enhanced capacitive performance are prepared using MnO₂ as a charge storage material and carbon nanotubes (CNT) as conductive additives. The enhanced capacitive properties are linked to the beneficial effects of catecholate molecules, such as chlorogenic acid and 3,4,5-trihydroxybenzamide, which are used as co-dispersants for MnO₂ and CNT. The dispersant interactions with MnO₂ and CNT are discussed in relation to the chemical structures of the dispersant molecules and their biomimetic adsorption mechanisms. The dispersant adsorption is a key factor for efficient co-dispersion in ethanol, which facilitated enhanced mixing of the nanostructured components and allowed for improved utilization of charge storage properties of the electrode materials with high active mass of 40 mg cm⁻². Structural peculiarities of the dispersant molecules are discussed, which facilitate dispersion and charging. Capacitive properties are analyzed using cyclic voltammetry, chronopotentiometry and impedance spectroscopy. A capacitance of 6.5 F cm⁻² is achieved at a low electrical resistance. The advanced capacitive properties of the electrodes are linked to the microstructures of the electrodes prepared in the presence of the dispersants.     

高固含量Si3N4/B4C水基悬浮体的制备

高固相、低粘度Si3N4/B4C水基悬浮体的制备是实现陶瓷材料凝胶注模成型工艺的关键和前提.以Si3N4和B4C为初始原料,选择合适的分散剂聚乙烯吡咯烷酮(PVP),通过优选工艺参数,10%的B4C和90%的Si3N4与H2O混合,加入1.5 mg/m2PVP,调节pH=10.5,即可制备出固相体积分数为60%,粘度小于1 Pa*s的Si3N4/B4C水基悬浮体.     

橡胶乳液——无机复合粉体体系稳定性研究

文章用不同类型的分散剂制备出不同粒径的PbWO_4,与超细WO_3复合得到PbWO_4-WO_3无机复合浆体,将此浆体以不同的量与一定量的橡胶乳液混合,并用氨水调节pH值,得到的橡胶乳液-无机复合粉体体系。结果发现:用多季铵阳离子分散剂制备的活性PbWO_4与超细WO_3按40:60复合得到的浆体再与橡胶乳液按7.2:10混合(浆体中固含量57%),调节pH=10-11,经静置96h后,仍无沉淀和分层,体系仍具有较好的流动性。橡胶乳液-无机复合粉体体系中的固体填充物含量可提高到25%。