Polyacrylic acid effect

Ferretti, R., Zhang, J. and Buffle, J. (1997). Kinetics of hematite aggregation by polyacrylic acid effect of polymer molecular weights. Colloids Surf. A, 121, 203-215. 

FIGURE 4.17 Effect of ionic strength on the elution of anionic polymers. Column TSK-GEL GMPW, two 17 fjLirt, 7.5 mm X 60 cm columns in series. Sample 0.5 ml of 0.05-0.1% of the sodium salt of polyacrylic acid, an anionic polymer. Elution Water 0.01, 0.025, 0.05, or 0.1 M NaNOs in water. Flow rate 0.5 ml/min. Detection Rl. 

We also studied the effect of initiator on the dispersion polymerization of styrene in alcohol-water media by using a shaking reactor system [89]. We used AIBN and polyacrylic acid as the initiator and the stabilizer, respectively. Three different homogenous dispersion media including 90% alcohol and 10% water (by volume) were prepared by using isopropanol, 1-butanol, and 2-... 

We have also examined the effect of stabilizer (i.e., polyacrylic acid) on the dispersion polymerization of styrene (20 ml) initiated with AIBN (0.14 g) in an isopropanol (180 ml)-water (20 ml) medium [93]. The polymerizations were carried out at 75 C for 24 h, with 150 rpm stirring rate by changing the stabilizer concentration between 0.5-2.0 g/dL (dispersion medium). The electron micrographs of the final particles and the variation of the monomer conversion with the polymerization time at different stabilizer concentrations are given in Fig. 12. The average particle size decreased and the polymerization rate increased by the increasing PAAc concentra-... 

Lin, TH Phillies, GDI, Prohe Diffusion in Polyacrylic Acid Water—Effect of Polymer Molecular Weight, Journal of Colloid and Interface Science 100, 82, 1984. 

Jacobsen, A. (1962). Configurational effects of binding of magnesium to polyacrylic acids. Journal of Polymer Science, 57, 321-36. 

The proposed mechanism of effect of surfactant and ultrasound is reported in Fig. 7.5. The long chain surfactant molecules attach to surface of nanoparticles due to physical adsorption. Only thin layer is adsorbed onto the CaC03 nanoparticles. Due to presence of ultrasound and use of surfactant will control the nucleation. Surfactant keeps the particles away from each other by preventing flocculation due to change in surface tension of reaction mass. The concentration of additives was changed from 0.2 to 1.0 g/L. Addition of 0.2 g/L tripolyphosphate shows the increase in the rate of precipitation which is determined from the Ca(OH)2 consumption. Polyacrylic acid shows the least rate of precipitation (0.115 mol/1), which... 

A comparison of Tables 9-12 indicates that naturally occurring species tend to produce stable membranes more abundantly. We believe this is due to the cyclic nature and rigidity of the backbone, as will be discussed in the following section of the paper. Several trends are immediately obvious. For example, the hydrophobicity of the polymer appears to be a critical parameter. While polyacrylic acid can form a stable membrane with virtually all polycations, poly-methacrylic acid is much less effective. Similarly, propylene glycol modified alginate is less effective than sodium alginate. Furthermore, when the poly-... 

The highest PGM recovery was achieved using collector PM443, which is an amine + ester-modified xanthate. Among the chromium slime depressants evaluated, modified mixtures of organic acids, RQ depressants and a low-molecular-weight polyacrylic acid + pyrophosphate mixture were there. The effect of different chromium depressants on chromium assays of the PGM concentrate are illustrated in Figure 18.7. 

Figure 3.23 The tertiary electroviscous effect observed for particles of polystyrene latex with a copolymer of polyacrylic acid at the outer surface. The experimental points were obtained at pH 3 and 10. The dry particle radius was 75 nm and Ka 25...

The first section, Chemical Reactions on Polymers, deals with aspects of chemical reactions occurring on polymers—aspects relating to polymer size, shape, and composition are described in detail. One of the timely fields of applications comprises the use of modified polymers as catalysts (such as the immobilization of centers for homogeneous catalysis). This topic is considered in detail in Chapters 2, 3, 8, 9, and 11 and dealt with to a lesser extent in other chapters. The use of models and neighboring group effect(s) is described in detail. The modification of polymers for chemical and physical change is also described in detail in Chapters 2 (polystyrene) 4 (polyvinyl chloride) 5 (polyacrylic acid, polyvinyl alcohol, polyethyleneimine, and polyacrylamide) 6 (polyimides) 7 (polyvinyl alcohol) 8 (polystyrene sulfonate and polyvinylphosphonate) 10 (polyacrylamide) and 12 (organotin carboxylates). 

The presence of pre-adsorbed polyacrylic acid significantly reduces the adsorption of sodium dodecylsulfonate on hematite from dilute acidic solutions. Nonionic polyacrylamide was found to have a much lesser effect on the adsorption of sulfonate. The isotherm for sulfonate adsorption in absence of polymer on positively charged hematite exhibits the typical three regions characteristic of physical adsorption in aqueous surfactant systems. Adsorption behavior of the sulfonate and polymer is related to electrokinetic potentials in this system. Contact angle measurements on a hematite disk in sulfonate solutions revealed that pre-adsorption of polymer resulted in reduced surface hydrophobicity. 

The percent inhibition was calculated according to the equation in Table II. As shown in Table II, the results indicated that when compared to the polyacrylic acid, copolymers of acrylic acid and N-(hydroxyalkyl)-acrylamide were quite effective in inhibiting calcium phosphate formation at the normal use dosage of 10 to 20 ppm. Among the three copolymers tested, acrylic acid/... 

After equilibrium, filtration, and pH adjustment, the residual calcium ion concentration was then titrated by EDTA solution. A higher residual calcium ion concentration indicates better inhibition activity and, therefore, more effectiveness in controlling calcium carbonate deposition in the treated water. As shown in Table III, at dosages of 1 to 5 ppm, the polyacrylic acid was more effective than the acrylic acid/N-(hydroxyalkyl)-acrylamide copolymers. 

As shown In Tables IV and V, copolymers were quite effective in dispersing iron oxide and clay as compared to polyacrylic acid. Among the polymers tested, acrylic acid/N-(2-hydroxyethyl)acrylamide seemed to be the most effective. 

Prior to the use of the adhesives, the dentin surface is etched with a conditioning solution which is usually an aqueous acidic solution of citric acid-ferric chloride, phosphoric acid, or even polyacrylic acid [192]. These solutions tend to demineralize the dentin and expose the collagen (organic fibers in the dentin) [193], and thereby result in higher bond strengths. The effects of various pre-conditioning treatments on the bond strength of 4-META to dentin have been discussed [194]. 

Synthetic muscle systems were first mentioned by Flory in 1953 and defined in the context of this chapter by Kuhn et al. 5° Flory described the effect of temperature on a polyacrylic acid-polyvinyl alcohol blend. Kuhn studied pH, temperature, and ionic strength stimuli. Tanaka et al. made a significant contribution to the technology in an experiment that combined the contraction-relaxation phenomenon with stimuli developed indirectly by an electric current. Their work resulted in a patent. ... 

FIGURE 8.5 Effects of ions on polyacrylic acid gels. 

Mills, P. Woods, R. (1984). The effect of polyacrylic acid, acetyl salicylic acid and salicylic acid on resistance of cucumber to Col-letotrichum lagenarium. Phytopathologische Zeitschrift 111, 209-16. 

Morimoto, K., et al. 1985. Effect of non-ionic surfactants in a polyacrylic acid gel base on the rectal absorption of [Asul,7]-eel calcitonin in rats. J Pharm Pharmacol 37 759. 

Morimoto, K., et al. 1982. Effective vaginal absorption of insulin in diabetic rats and rabbits using polyacrylic acid aqueous gel bases. Int J Pharm 12 107. 

The effect of temperature and volume on the order parameter, s, in polyacrylic acid. The order increases with pressure and decreases with temperature. The straight lines indicate the validity of Equation 16.4. Data from J. R. McColl and C. S. Shih, Phys. Rev. Letters 29 (1972) 85. 

Figure 7.8 Effect of various stationary phases on the separation of FITC-labeled peptides. VSA, poly(vinylsulfonic acid) PAA, polyacrylic acid and PS-SA, poly(styrenesulfonic acid) [24].

Polyacrylic acid stabilised latices have been prepared by aqueous dispersion polymerisation. The method used is analogous to the non-aqueous dispersion (NAD) polymerisation methods originally used to prepare polymethyl methacrylate particles in aliphatic hydrocarbons (1. In effect the components of a NAD polymerisation have been replaced as follows aliphatic hydrocarbon by aqueous alcohol, and degraded rubber, the stabiliser, by polyacrylic acid (PAA). The effect of various parameters on the particle size and surface charge density of the latices is described together with details of their colloidal stability in the presence of added electrolyte. 

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