Polymer latex characterization

Bonardi, C., Christou, Ph., Llauro-Darricades, M.E., Guillot, J., Guyot, A. and Pichot, C., 1989, Polymer Latex III International Conference, Characterization of Acrylic Latexes Functionalized by N-Methylol Acrylamide, 6/1-6/14, Plastics and Rubber Institute, London. 

Latex paints Latex paints today account for more than one-half of the commercial paint sold. They are characterized by quick drying (generally several minutes to several hours), little order, and easy cleanup (with water). Latex paints are polymer latexes to which pigments have been added. The film is formed by coalescence of the polymer particles on evaporation of the water. The polymer itself is not water soluble, though these paints are called waterborne coatings. 

Marshall, T. R., C. S. Parmenter, and M. Seaver, 1976. Characterization of polymer latex aerosols by rapid measurement of 360° light scattering patterns from individual particles, J. Colloid Interface Sci., 55, 624-636. 

In agreement with our earlier studies (1,15), the adsorption results of Igepal CO-630 on the three vinyl acrylic latexes show that the area per molecule of surfactant can be related to the polarity of polymer surface. Further, the results show that one can employ the techniques discussed above to characterize the polarity of co-polymer latex surfaces. 

At the steps before the elaboration of carbon nanotube nanocom-posites, wet-STEM can be used for the characterization of nanotubes dispersed in a liquid (see Figure 3.18), and for polymer latex/ nanotubes mixing (before evaporation or freeze-drying to elaborate polymer/carbon nanotube nanocomposites). 

Barman BN, Giddings JC (1993) Separation and characterization of polymer latex beads and aggregates by sedimentation field-flow fractionation. In Provder T (ed) Chromatography of polymers characterization by SEC and FFF. American Chemical Society, Washington, DC, pp 30-46... 

Emulsion polymenzaticm without the use of an emulsifier may be achieved even with a monomer with v ter solubility as low as thet of styrene provided one uses an initiator such as potassium persulfate which introduces ionic end groups into the polymer that can stabilize the polymer latex particles produced electrostatically. Emulsifier free emulsion polymerization is advantageous when the object is to obtain a well-characterized model colloid for use in experiments on colloidal stability, etc. Then it is usually desirable that the surfaces of the colloidal particles be clean. When an emulsifier is used in the iH eparation, its removal (e.g., by dialysis) is generally so incomplete that it is simpler to avoid its use in the first place. However, emulsifier-free latexes are necessarily dilute and consequently of little interest for commercial applications. 

This chapter is concerned with just one of this class of thickeners, namely a hydrophobically modified (hydroxyethyl)cellulose (HMHEC), Hercules WSP D-47. Gelman and Barth (i) reported on the viscosity of such HMHECs. This sample contained up to four hexadecyl chains grafted to the cellulose backbone. The preparative route was that described by Landoll (2). The dilute solution properties were characterized by capillary viscom-etry, whereas the more concentrated solutions were characterized by continuous-shear viscometry, forced oscillation measurements, and shear-wave propagation. In addition, the adsorption onto polymer latex particles was investigated. 

Those emulsion polymerizations for which initially polymer latex particles are not present, but in which particles are formed by some of the mechanisms described above, are known as ab initio. Seeded emulsion polymerizations are those in which at the beginning of the process there are preformed (and usually characterized) polymer latex particles this kind of polymerizations are commonly used in industry to avoid the variability of the process associated with the nucleation stage. 

Characterization of polymer latexes can be performed by techniques available for polymers in general and by other techniques specific for emulsions. 

In the polymer industry, packing material, laminates including multilayer films, pellets or molded products can be analyzed by NIR. Even polymer latex particles with up to 99 % water content may be analyzed. NIR provides information about reaction mechanisms, polymerization, crystallinity, orientation, water content and hydrogen bonding, even during the process of polymer manufacture. For example the disappearance of the double bonds in polyethylene and polypropylene can be monitored. In the NIR spectrum C=C bonds lead to a combination band at about 4740 cm and a first overtone at about 6170 cm NIR spectroscopy is applied to characterize ester-, nitrile-, or amide-based acrylic and methacrylic polymers. Other examples are the identification of polyvinylchloride, polyvinyl alcohol and polyvinyl acetates or the analysis of polymerization in epoxy and phenolic resins. 

M. Nomura, J. Ikoma and K. TnjitSi, in Polymer Latexes Preparation, Characterization. and Applications, E. S. Daniels, E. D. Sudol and M. S. El-Aasser (eds), American Chemical Society Symposium Series, Vol. 492, Washington, DC, 1992, p 55... 

Atlanta 1991, Polymer Latexes Preparation, Characterization and Applications,... 

B. R. Morrison, I. A. Maxwell, R. G. Gilbert and D. H. Nqrpa, iiu ACS Symp. Series — Polymer Latexes — Preparation, Characterization and Applications,... 

Guo JS, Sudol ED, Vanderhoff JW, El-Aasser MS (1992) In Daniels ES, Sudol ED, El-Aasser MS (eds) ACS symposium series polymer latexes - preparation, characterization and applications, vol 492. American Chemical Sodety, Washington, DC, p 99... 

Particle electrophoresis has proved to be very useful in many areas of theoretical and practical interface and colloid science, including model polymer latex and silver halide systems, and more practical problems related to water purification, detergency, emulsion science, the characterization of bacterial surfaces, blood cells, viruses, and so on. With the advent of more sophisticated computer data analysis and laser hght sources, the limits of resolution for particle sizes that can be analyzed has been, and is being, steadily reduced, so that with proper (and more expensive) instrumentation, the electrophoretic nature of particles in the size range of a few nanometers can be readily determined. 

S. Lee, A. Rudin, in Polymer Latex Preparation, Characterization and Application, ed. by... 

The adsorption of a non-ionic surfactant onto latex particles was studied by small-angle X-ray scattering(SAXS). The analysis of the process of adsorption by S AXS was examined in detail. It was shown that SAXS allowed monitoring of the gradual build-up of the surface layer with increasing amount of added surfactant. SAXS also allowed the radial volume fraction of the hydrophilic tails of the surfactant to be obtained. Possible limitations of this method of analysis are discussed. 21 refs. (7th Dresden Polymer Discussion, Characterization of Sorption Phenomena from Solution to the Surface, Meissen, Germany, April 1999)... 

W.-H. Hou, T.B. Uoyd, F.M. Fowkes, Pigmented Polymer Particles with Controlled Morphologies, in Polymer Latexes preparation, characterization and applications, E.S. Daniels, T. Sudol and M. El-Aasser (Eds.), ACS Symposium Series 492, Washington DC, 1992, Chap. 25, pp. 405-421. 

P. A. Lovell, T. H. Shah, and F. Heatley, in E. S. Daniels, E. D. Sudol, and M. El Asser, eds., Correlationof the extent of chain branching with reactor conditions for emulsion polymerization of n-butyl acrylate ACS Symposium Series, k Polymer Latexes-Preparation, Characterization and Applications, Vol. 492 ACS Washington, D.C., 1992, pp. 188-202... 

---