PPG型聚氨酯原油破乳剂的合成

用聚丙二醇和甲苯二异氰酸酯为原料,二甲苯为溶剂合成了聚氨酯型原油破乳剂(PPG)。对不同含水率的油水乳状液及原油进行了破乳试验,选出了最佳用量。结果表明PPG对原油的适应性强,破乳速度快,用量低。     

三单体接枝共聚物对PP/云母填充体系性能的影响

将固相法接枝合成的聚丙烯与甲基丙烯酸甲酯／马来酸酐／丙烯酸丁酯的接枝共聚物PP-g-MMA/MAH/BA应用于PP／云母填充体系。研究接枝物对体系的力学性能、微观形态、热性能、加工性能及表面性能等的影响。结果表明,在PP／云母填充体系中加入适当的三单体接枝共聚物,可提高体系的拉伸强度、弯曲强度、维卡软化点及表面极性,并降低制品的成型收缩率;同时,体系的加工性能也得到改善。     

共聚型丙烯酸酯抗冲改性剂的合成及其对PVC的改性

采用乳液聚合法合成了核壳结构的丙烯酸酯共聚物（ACR）。借助于动态光散射粒径分析法,透射电镜,IR,DSC考察了ACR共聚物乳胶粒径,核壳结构,组成变化及玻璃化转变。发现层单体比对缺口冲击强度有较大影响,缺口冲击强度随着核层橡胶相质量的增加而明显上升。此外还考察了复合乳化剂使用的情况,并用扫描电镜观察了冲击样条断面的形貌特征。这种ACR与PVC共混后能显著提高其冲击强度。     

AM/AA/MA三元共聚物降失水剂PL-1的室内研究

以氧化还原体系为引发剂,在40±2℃和氮气保护的条件下用丙烯酰胺、丙烯酸、马来酸酐三种单体进行水溶液共聚,合成了 PL-1水泥浆降失水剂。考察了 PL-1对水泥浆失水量、流变性、稠化时间等性能的影响。结果表明,PL-1的合成条件简便,具有良好的耐温和抗剪切性,对水泥浆有很强的降滤失作用及良好的分散作用。     

Laccase mediated conjugation of sugar beet pectin and the effect on emulsion stability

Laccase catalyzes intermolecular cross-links between ferulic acid of sugar beet pectin (SBP). Conjugation of SBP by laccase was confirmed by increased molecular weight, monitored by size exclusion chromatography, combined with multi-angle laser light scattering (SEC–MALLS), by reduced ferulic acid concentration detected at UV 325 nm, as well as by increased particle size. In addition, cross-linked SBP developed a more compact, branched structure as verified by a smaller root mean square (RMS) when molecular weight increased. Emulsions prepared with conjugated SBP had significantly smaller d_4,3 diameter and uniform droplet size, with more negative ζ-potential than non-treated SBP, during 30 days storage at 37 °C. The d_4,3 diameter was 5.3 μm and 3.8 μm for SBP and conjugated SBP, respectively. Covalently conjugated SBP has increased functionality and improved emulsion stability, most likely attributable to development of thick layer at the oil interface.     

Synergistic Functionality of Soybean 7S and 11S Fractions in Oil-in-Water Emulsions: Effect of Protein Heat Treatment

Oil-in-water emulsions stabilized by different concentrations of two fractions (7S and 11S) of soy protein, with or without heat treatment at 70 or 90°C, were investigated. Emulsions stabilized by 7S showed smaller droplets than those containing 11S. Moreover, emulsions stabilized by heat treated mixtures enriched in 11S produced gel after high pressure homogenization. Emulsions produced from 75% of 7S and 25% of 11S without or with heat treatment at 70°C showed the smallest droplets, indicating a synergistic effect between them. Thus, the combination between 7S and 11S has a great potential to be used as natural emulsifier in food-grade emulsions.     

无皂乳液聚合法制备喷水织机用浆料的研究

探讨喷水织机适用浆料的制备方法。采用无皂乳液聚合方式,合成了醋酸乙烯酯、丙烯酸、丙烯酸甲酯、丙烯酸丁酯、甲基丙烯酸甲酯多元共聚物,探讨了油酸用量、过硫酸铵用量、反应温度对乳液稳定性、黏度、转化率以及浆膜水溶性的影响。结果表明:油酸和过硫酸铵用量分别为混合单体总质量的2.0%、0.5%,反应温度为75℃,共聚乳液具有良好的性能。     

Ionic autocrosslinking of water-based polymer latices: A new concept of acid–base interaction occurring upon film formation

Latices of the terpolymer styrene/butyl acrylate/acido-basic monomer, the monomer having either a basic chemical group or an acidic chemical group, were separately prepared by free-radical emulsion polymerization using the nonionic surfactant poly(oxy-1,2-ethanediyl) as steric stabilizer. The basic polymer latices were prepared using 1, 3 or 5% of 2-(dimethylamino)ethyl methacrylate, whereas the acidic polymer latices were prepared using 1, 3 or 5% of acrylic acid (mol% relative to conventional monomers, styrene and butyl acrylate). Blends of the basic and the acidic polymer latices were prepared by simply mixing equal molar quantities of basic and acidic latices. The resulting blends were stable as the steric stabilization prevented unlike particles from colliding. Upon film formation, coalescence of the particles took place, with formation of ionic clusters due to proton exchange from the acidic monomer units to the basic monomer units of neighbouring unlike particles. This constitutes a reversible ionic crosslinking at the periphery of neighbouring particles, which affects the various film properties to different extents.     

Emulsion Prevention with Supported Liquid Membrane Permeation

The urge to achieve climate protection goals and a more prevalent interest in finding alternatives to fossil fuel‐based products focus attention increasingly on cascade raw material utilization, respectively, to intensify commercial production processes. The present project provides a study on the combination of liquid‐liquid extraction and esterification using the system acetic acid/octanol and 4‐dodecylbenzenesulfonic acid as catalyst. The surfactant 4‐dodecylbenzenesulfonic acid causes emulsification during extraction, but emulsification was successfully avoided by using supported liquid membrane permeation equipment.     

OPTIMAL CONTROL OF THE PENICILLIN G FED-BATCH FERMENTATION: AN ANALYSIS OF A MODIFIED UNSTRUCTURED MODEL

This paper presents the application of optimal control theory in determining the optimal glucose feed rate profile for the penicillin G fed-batch fermentation, using a modified unstructured mathematical model based on balancing methods. This updated model allows for a smooth transition between maintenance and endogenous metabolism, while all variables take on physically acceptable values under all conditions

It is illustrated that the resulting computational algorithm is independent of the exact nature of the metabolism (maintenance or endogenous). In this scheme, the unusual optimization of some free initial states is included. However, as shown by simulations, the nature of the metabolism might be a key factor in concluding whether or not altering the substrate feeding strategy has an important influence on the final amount of product

Mathematical and microbial insight leads to the construction of an alternative suboptimal heuristic