Ratios in Copolymers

The properties of a latex depend on the nature of polymers in the latex, particularly the monomer ratio in copolymers and the type and amount of plasticizers. The monomer ratio affects the strengths of the latex modified mortars to the same extent as the polymer-cement ratio [87, 92]. Mechanical and chemical stability, bubbling and coalescence on drying all depend on the type and amount of surfactants and antifoamers and the size of dispersed polymer particles. It is important that the use of selected antifoamers and surfactants as stabilizers or emulsifiers produces no adverse effect on cement hydration. 

Hydrogel System Monomer Feed Monomer Ratio in Copolymer" HEMA STY Precipitant Conv. % Mol. Wt. 10 Solvents... 

Relationship Between Sensitivity and Component Ratio in Copolymer Resists... 

The relationship between sensitivity and component ratio in copolymer negative resists was studied theoretically on the basis of Charlesby s gel formation theory. The formulas for sensitivity as a function of component weight ratio are derived for a nonchain reaction and for a chain reaction, respectively. Copolymer sensitivities for any component ratio can be estimated numerically using the derived formulas, from the data on sensitivities for homopolymers composed of individual constituent monomers in the copolymer. The calculated results are in good agreement with the experimental data reported. 

Research on the effect of monomer ratio in copolymer dispersions [e.g., SBR latex, poly (ethylene-vinyl acetate) (EVA) and poly (styrene-acrylic ester) (SAE) emulsions] on the strength of polymer-modified mortar using copolymer dispersions [21-23]... 

Prebyl, B.S., Johnson, J.D., Cook, K.D. (2004) Calibration for determining monomer ratios in copolymers by electrospray ionization mass spectrometry. Int. J. Mass Spectrom., 258,207-214. 

Determination of monomer ratios in copolymers, e.g., ethylene oxide-vinyl chloride (Figure 3.4), tetrafluoroethylene-hexafluoropropylene. 

Smith [841] has discussed applications of pyrolysis techniques for polymeric systems with emphasis on the qualitative identification of components in a copolymer or polymer blend, identification of low-level polymer contaminants, characterisation of copolymer sequencing, differentiation between copolymers and physical blends of homopolymers, determination of monomer ratios in copolymers, and the study of polymer kinetics and degradation mechanisms. Pyrolysis destroys the stereostructure of the polymers. Gaseous components generated from pyrolysis of a wide variety of polymers have been analysed both off-line and on-line by IR spectroscopy to determine (quantitatively) the major components of the parent resin, e.g. rubbers... 

Other infrared methods for the determination of the ethylene - propylene ratio in copolymers are reviewed in Table 4.2. 

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