摘要:

During emulsion polymerization of vinyl acetate (VAc) specific interactions surfactant-monomer and surfactant-initiator has been evidenced. Due to this interactions the cmc of the surfactant is higher and the electrical conductivity sharply decreases at surfactant /initiator molar ratio = 1. At this ratio high chemical interaction between surfactant and initiator-has been observed. The surfactant was dissodium salt of the sulfosuccinic acid with nonyl phenol ethoxylated having 25 moles ethylene oxide (NPED25SS) and the initiator was potassium persulfate (KPS). The surfactant-monomer interaction reduces the concentration of free surfactant and consequently the rate of initiator decomposition. For the polymerization reaction, the initiator productivity is higher at lower surfactant concentration. fit a surfactant/initiator molar ratio = 1 this productivity is smaller at constant surfactant concentration.

ISSN:0193-2691    

DOI:10.1080/01932699608943500

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The L-phase of the three-component system water - sodium octanoate -butanol extends over a large composition range. It is well known that micellar aggregates exist in the water rich part (the L1part) and inverse micellar aggregates in the butanol rich part (the L2part). The mechanism for the change from a continuous water medium to a continuous butanol medium in the middle part is of fundamental interest. The properties of the L-phase were studied by density, refractive index, ultracentrifugation, electromotive force and conductivity measurements. This investigation indicates in which regions aggregation occurs as well as the changes in aggregate and medium structure which take place with increased butanol concentration.

ISSN:0193-2691    

DOI:10.1080/01932699608943501

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Effects of emulsifying chemicals and emulsion aging on the sizing performance of alkenyl succinic anhydride (ASA) were investigated. The emulsifying chemicals were nonionic and anionic surfactants and cationic starches. Image analysis in emulsion quality control was applied. It was found that the use of surfactants may deteoriate remarkably the sizing efficiency if the surfactant and its dosage is not carefully chosen. The need for surfactants in emulsification was affected by the properties of ASA and the mixing energy available. The act of cationic starch both as an effective stabilizer and as a retention agent in ASA-sizing systems was established.

ISSN:0193-2691    

DOI:10.1080/01932699608943502

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The effects of the mixing process and pH on the available chlorine content of the decontaminant calcium hypochlorite (or high-test hypochlorite, HTH) in the organic solvent-HTH-water mixture have been studied in order to develop new emulsion systems for the decontamination of polymer-thickened chemical warfare agents. A series of water-soluble and water-insoluble organic solvents were investigated. The observed temperature increase during the mixing of the water-soluble organic solvents with HTH and water was found to be mostly resulted from the mixing enthalpy of the solvent with water. It can be minimized by using a new mixing procedure. The effectiveness of HTH as the decontaminant was evaluated by monitoring the available chlorine content of the system at various time intervals after mixing. An increase in the basicity of the solvent-HTH-water system generally leads to a higher chlorine content. For the systems with the water-insoluble organic solvents, there was neither noticeable increase in temperature during the mixing nor significant loss of the chlorine content.

ISSN:0193-2691    

DOI:10.1080/01932699608943503

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The aim of the present work is to study the influence of the sequential or competitive adsorption of anti-HSA (Human Serum Albumin) IgG and RSA (Rabbit Serum Albumin) onto a negatively charged polystyrene latex on the colloidal stability of the immunoiatex (IgG-RSA/latex). Anionic (1-2) latex was prepared by surfactant free emulsion polymerization. Adsorption of IgG and RSA on the latex 1-2 was performed at low ionic strength and different pHs. Sequential and competitive adsorption of a-HSA IgG and RSA were performed

ISSN:0193-2691    

DOI:10.1080/01932699608943504

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The effect of mixed micelles (polyethylene glycol-CTAB cationic surfactant, shortchain alcohol-SDS anionic surfactant) on the alkaline hydrolysis of normal aliphatic esters has been studied at 20 and 30°C with the method of difference of thermogram-area of thermokinetics in this paper. The results indicate that this reaction is inhibited by the single and mixed micelles. The mixed micelles of PEG and CTAB exhibit a greater effect of inhibition on the reaction than those do in single PEG or CTAB systems. The extent of inhibition for the reaction in the mixed micelles of SDS and alcohol is less than that in single SDS micellar solutions. The critical micellar concentrations of the corresponding systems have also been measured with the conductivity method in this paper.

ISSN:0193-2691    

DOI:10.1080/01932699608943505

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932699608943506

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor