Latex analysis

NR part of NR. dry NR 1 iberat This is kca1/mo Experim or CHCl i rrad ia inc reas A t latex analysi inc reas that C Cl radi Table... 

An example of latex analysis is shown in Figure 10a, where each of the spikes indicates the passage of a 0.57 micron tagged latex particle through the detector volume. Here, rather than measuring concentration, the detector counts individual events. For smaller particles, as shown in Figure 10b for 0.1 micron particles, the analysis produces a chromatographic peak because many particles can simultaneously reside in the detector volume, and the de-... 

Accordingly GPC analysis of dried latex samples were carried out. The carrier solvent was tetrahydrofuran and peaks were monitored by a Waters dual absorbance detector at wavelengths of 2 h and 3U0 nm. The latter detection was the closest to 350 nm available. 

Figure 7. GPC analysis of (A) 312-nm Dow latex sample SE Dupont silica columns—(a) response at 254-nm wavelength (full scale 0.5 A) (b) response at 340-nm wavelength (full scale 0.02 A) (B) 220-nm Dow latex sample E-Linear Watefs silica columns—response at 254-nm wavelength (full scale 0.5 A) (C) 98-nm Polysciences latex sample E-Linear WatePs silica columns—response at 254-nm wavelength (full scale 0.5 A) (D) 183-nm Polysciences latex sample E-Linear Water s silica columns—response at 254-nm wavelength (full scale 0.5 A)...

Exclusion Chromatography Analysis of Latex Solutions for Monitoring Nitrile Resin Polymerizations... 

Latex solutions for chromatographic analysis were prepared by adding weighed amounts of latex to known amounts of acetonitrile. Latex solution concentrations were 0. 2 g/100 ml for AN/S copolymers and 1. 0 g/100 ml for the AN/MA graft resins. 

The latex solutions were filtered through a 0. 9 pm filter prior to chromatographic analysis. Known volumes of the filtered solutions were injected into the chromatograph by loop injection. Injection volumes were 250 pi of AN/M solutions and 500 pi of AN/S solutions. 

Overall goal of this work was to maximize the amount of information obtained from chromatographic analysis of latex solutions. More specific aims were (1) measure amounts of unreacted monomers, as one measure of conversion, (2) determine amount of polymer, as a second measure of conversion, (3) estimate chemical composition of the polymer formed, and (4) look for evidence of grafting (in the AN/M polymerization) as evidenced by detection of insoluble polymer formation. 

Ability to analyze unreacted monomers was dependent on detector selectivity. The UV detector was operated at 254 nm for analysis of AN/S latex solutions. Styrene is a strong UV abosrber at this wavelength while acrylonitrile has no measurable absorbance at 254 nm. Thus, the UV detector was entirely selective to monomeric styrene. The refractometer detector was sensitive to both acrylonitrile and styrene when each was present in the desired copolymer proportions (70/30). However,... 

Dingenouts, N., Bolze, J., Potschke, D., Ballauf M. Analysis of Polymer Latexes by Small-Angle X-Ray Scattering. VoL 144, pp. 1-48... 

Detailed quantitative analyses of the data allowed the production of a mathematical model, which was able to reproduce all of the characteristics seen in the experiments carried out. Comparing model profiles with the data enabled the diffusion coefficients of the various components and reaction rates to be estimated. It was concluded that oxygen inhibition and latex turbidity present real obstacles to the formation of uniformly cross-linked waterborne coatings in this type of system. This study showed that GARField profiles are sufficiently quantitative to allow comparison with simple models of physical processes. This type of comparison between model and experiment occurs frequently in the analysis of GARField data. 

The contribution of the adsorbed HPC layer to the encapsulation was also illustrated by GPC analysis for the latex polymer. 

When pressure is applied to the latex, the UCFT is seen to move to higher temperatures as indicated in Figure 2. It was found that the PMMA latex stabilized by PIB of Mn - 2 x lCrcould be fitted to the same curve as the PVAc latex stabilized by PIB of Mjj 4 x 10. A linear regression analysis of the UCFT as a function of applied pressure gave ... 

Colloidal particles, foams used to collect and separate, 12 22 Colloidal powders, 23 55-56 Colloidal silica, 22 380, 382, 384 applications of, 22 394 modification of, 22 393-394 preparation of, 22 392-393 properties of, 22 391-392 purification of, 22 393 Colloidal silica gels, 23 60 Colloidal solids, 7 293-294 Colloidal stability, 7 286-291 10 116 22 55 Colloidal stabilizers, in polychloroprene latex compounding, 19 857 Colloid mills, 8 702 10 127 Colloids, 7 271-303 23 54. See also Polymer colloids analysis, 7 296 applications, 7 292-296 conducting, 7 524... 

The engineering analysis and design of these operations addresses questions which are different than those addressed in connection with the shaping operations. This is illustrated in Fig. 1 which is a flow sheet, cited by Nichols and Kheradi (1982), for the continuous conversion of latex in the manufacture of acrylonitrile-butadiene-styrene (ABS). In this process three of the nonshaping operations are shown (1) a chemical reaction (coagulation) (2) a liquid-liquid extraction operation which involves a molten polymer and water and (3) a vapor-liquid stripping operation which involves the removal of a volatile component from the molten polymer. The analysis and design around the devolatilization section, for example, would deal with such questions as how the exit concentration of... 

When selecting a particle for analysis, it is important to consider the effects of particle size on fluorescence histogram coefficient of variation (CV). Small particles of uniform size, such as 1 pm diameter latex spheres, exhibit a sharp, narrow histogram with a relatively small CV (Fig. lA). Spherical bacteria. 

---