不同分散剂对SiC晶须分散作用的探讨

利用离心沉降分光光度法对SiC晶须在4种不同分散剂中的分散行为进行了研究,探讨了不同分散剂的分散效果,并对其分散机理进行了分析.结果表明,分散剂的分散能力顺序为焦磷酸钠＞六偏磷酸钠＞吐温80＞聚乙二醇;不同类型分散剂混合使用的分散效果要比使用1种分散剂的好.     

Synthesis of silicon ester dispersants and its application in CaCO3/polyethylene composites

Silicon ester dispersants were prepared using transesterification between ethyl petroleum silicate and the alkyl alcohols by different molecular masses. The dispersants were used to modify calcium carbonate (CaCO₃), and their effect on the mechanical properties of CaCO₃/polyethylene (PE) composites was investigated. The transesterification was confirmed by gas chromatography (GC). The optimal conditions for the preparation of silicon ester dispersants were 110°C for 3 h with 2% catalyst by weight and fixed molar ratio of isooctyl alcohol to ethyl petroleum silicate of 3 : 1. Fourier transmission infrared spectroscopy (FTIR) results indicated that the dispersants were coating to the CaCO₃ particles. Dispersant with octadecanol as its solvable chain enabled the best modification effect. CaCO₃/PE composites modified by dispersants demonstrated improved mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

新型油溶性沥青质分散剂抑制重质原油沥青质沉积的研究

针对新疆重质原油沥青质沉积严重的问题,以聚异丁烯丁二酸酐、苯胺和对氨基苯酚为原料合成了尾部基团为高度枝链化的聚异丁烯基,头部基团分别为苯基及酚羟基的新型油溶性沥青质分散剂PA1和PA2。采用分光光度法与显微镜法评价了所合成分散剂对沥青质沉积的抑制效果。实验结果表明,分散剂PA2抑制沥青质沉积作用效果优于PA1。通过对分散剂PA2抑制沥青质沉积作用效果的评价,确定了最佳合成条件：对氨基苯酚与聚异丁烯丁二酸酐摩尔比为1.2,反应温度为120 ℃,反应时间为6 h。在分散剂PA2加入量为200 mg/L的条件下可以将新疆重质原油的初始絮凝点由-19.87提高到8.63,显著改善了新疆重质原油稳定性。     

Synthesis and Evaluation of New Anionic Gemini Dispersants as Oil Dispersants to Treat Crude Oil Spill Pollution

Floating petroleum oil spills on the marine ecosystem are generally associated with an escalation of serious environmental problems. This research aimed to synthesis five water-soluble anionic Gemini dispersants to minimize the effect of floating petroleum oil spills on the marine ecosystem. Referring to the spacer type, these dispersant are classified into two categories: the first category is the three acyl amine Gemini dispersants of N,N′- diacyl, (distearoyl-, dipalmitoy-, and dimyristoyl-) N,N-′ sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted S, P, and M, and the second category is two alkyl amine Gemini dispersants of N,N′dialkyl -(dicetyl-, and dilauryl-) N,N′-sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted C and L. Fourier transform infrared and ¹H NMR spectroscopy, gel permeation chromatography, and elemental analysis were used to verify the chemical formula of the synthesized dispersants. The effectiveness of the synthesized dispersants was investigated as regards their dynamic interfacial tension, carbon–chain length, and hydrophilic–lipophilic balance. The dispersion efficiency of the synthesized dispersant was detected qualitatively and quantitatively using the screen test and Warren Spring Laboratory methods, respectively. Experimental outcomes showed that the maximum dispersion efficiency of 94.7 wt% was achieved by dispersant C at a dispersant\oil ratio of 1:20 at 25°C.     

A new concept for dispersing agents in aqueous coatings

After a short overview about the development of synthetic dispersing agents for solvent-borne coatings up to the actual state of technique, analogous concepts of polymeric additives for water-borne coatings are introduced. The performance of these polyfunctional dispersants will be critically reviewed and described in comparison to dispersing agents based on new concepts. With these new concepts using mono- and difunctional oleochemical agents or a combination of them it is often possible to reach better performance than with polyfunctional polymers. During our study different physicochemical methods (Zeta potential, adsorption, desorption) and paint application tests including numerous binders and pigments were done. These investigations lead to the discussion of new models for the dispersing of pigments in water-borne coatings and to more knowledge about the design of a dispersant to reach high gloss, optimal rub-out and high color-strength. Furthermore the formulation of solvent- and resin-free water-borne pigment pastes is possible using dispersing agents selected by the new concepts.     

复配分散剂对ZrO2悬浮液稳定性的影响

本实验选用由乳化剂OP(壬基酚聚氧乙烯醚)与CPB(溴代十六烷基吡啶)所组成的复配分散剂对纳米ZrO2 进行分散,制备ZrO2 悬浮液,并讨论了复配分散剂两组分用量比、pH值、悬浮液中的离子强度等对悬浮液稳定性的影响.结果表明:加入复配分散剂得到的ZrO2 悬浮液,具有更好的分散稳定性;当OP与CPB用量比为1∶ 1,复配分散剂用量为ZrO2 含量的6%时,能使ZrO2 粉末具有良好的分散,在pH=1.8时,悬浮液颗粒粒径最小,中位粒径达到178 nm.实验中还发现,添加复配分散剂后悬浮液等电点由原来的pH= 6右移到pH=13附近,另外,增加悬浮液中的离子强度,使Zeta电位值降低,粒径增大,但离子强度大小并不会影响ZrO2 的等电点,其等电点仍保持在13左右.     

Synthesis and Evaluation of Some Detergent/Dispersant Additives for Lube Oil

With increasing demands being placed on lubricants for automotive engines and transmissions, it has been necessary to work to improve the function of these lubricants. Modern lubricants are formulated from a range of base fluids and chemical additives to enhance their actions or to add new properties. In this study we have confined ourselves to the study of the detergent/dispersant type of additives based on preparation of polyisobutylene succinic anhydride (PIBSA) and then the reaction of PIBSA with different polyethylene glycols and the amination of the products by different polyamines. The compositions of the prepared compounds were determined by molecular weight, I.R. and H-NMR spectroscopy. The efficiency of the prepared compounds as antioxidants and detergents/dispersants was investigated. It was found that the prepared compounds have very good dispersancy power and the efficiency increases by increasing the number of –NH groups in the prepared compounds and by increasing the molecular weight of the polyethylene glycols.     

Systematic Approach for Dispersion of Silicon Nitride Powder in Organic Media: II, Dispersion of the Powder

A novel dispersant—O-(2-aminopropyl)-O'-(2-methoxyethyl)-polypropylene glycol (AMPG)—was developed to disperse submicrometer-sized Si₃N₄ powder in nonaqueous media, based on the surface chemistry of the powder. The dispersing phenomena and mechanisms have been studied systematically, both in model systems (using atomic force microscopy and ellipsometry) and in powder systems (using rheological behavior and adsorption isotherms). The results from the model systems correlated well with those from wet powder systems. It is demonstrated that highly concentrated (with a solids volume fraction of >0.50) and colloidally stable nonaqueous Si₃N₄ suspensions can be realized using AMPG.     

纳米氧化锌的分散性研究

研究了单一、二元混合以及三元混合分散剂对纳米ZnO的分散效果,探讨了分散剂用量对纳米ZnO粉体分散性的影响.结果表明:二元混合分散剂分散效果优于单一分散剂;三元混合分散剂分散效果更佳,分散剂的用量为水的质量分数的0.4%时分散效果最好.