摘要:

To modify the dispersibility of an organic pigment, such as quinacridone and anthraquinone, in organic solvents, the surface grafting of polyesters onto organic pigments by the anionic ring-opening alternating copolymerization of epoxides with cyclic acid anhydrides initiated by potassium carboxylate (COOK) groups introduced onto these surfaces was investigated. The organic pigment having COOK groups was prepared by the following two methods: (a) the reaction of potassium carbonate with surface acyl chloride groups, which were introduced by the treatment of surface amino groups with adipoyl dich bride, and (b) the graft polymerization of potassium acrylate initiated by azo groups introduced onto the surface. The anionic ring-opening alternating copolymerization of epoxides with cyclic acid anhydrides was initiated by COOK groups introduced onto the organic pigment surfaces to give the corresponding polyester-grafted organic pigments. The dispersibility of organic pigments in organic solvent was remarkably improved by the grafting of polyesters onto the surface.

ISSN:0193-2691    

DOI:10.1080/01932699908943863

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The effect of retardation in the van der Waals interaction between two spherical particles is examined theoretically. The expressions which can be applied to Ka⩽ ⩽ obtained, in whichKis Debye-Hukel parameter, a is the radius of particles, D is the shortest distance between two spheres. An extensive comparison of exact, sophisticated and simplified treatments has been described. Computation results show that the improved approximations agree fairly well with exact computations and can be considered as the supplement of the classical Hamaker results. They should find application in problems of colloid stability and particle deposition.

ISSN:0193-2691    

DOI:10.1080/01932699908943864

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Using a radiosoptopic tracer to measure the concentration of demulsifiers,we studied the distribution regularity of demulsifiers between crude oil and water phases under different temperatures and found that the dewatering rate is related to the partition coefficient of demulsifier, which is quite sensitive to the variation of temperature According to the experimental results, we hold that an effective demulsifier should possess a relatively high partition coefTicient.

ISSN:0193-2691    

DOI:10.1080/01932699908943865

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The interaction between sodium dodecylbenezen sulfonate(SDBS) and Poly(ethylene oxide) (PEO) has been studied,' using surface tension and dye solubilization to determine the critical micelle concentration(CMC) without PEO, the critical aggregate concentration(cac) and polymer saturation concentration(c2) in the presence of PEO. The structure of surfactant-polymer complexes is analyzed by ESR and UV-vis spectra. For SDBS-PEO system, the result indicates that ptoymer-surfactant complexes have a more “ open” structure than the ordinary micelles. The polymer molecules may penetrate into the palisade of the micelles. Polyacrylamide(PAm) molecules remain in bulk solution as free molecules, and do not interact with SDBS.

ISSN:0193-2691    

DOI:10.1080/01932699908943866

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932699908943867

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932699908943868

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor