Emulsion Polymerization of Styrene and Vinyl Acetate with Cationic Surfactant (original) (raw)
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Emulsion polymerization of styrene: Nucleation studies with nonionic emulsifier
1982
The nucleation mechanism of styrene emulsion polymerization in the presence of the nonionic surfactant Emulphogene BC-840 was investigated. It was found that the conversion-time curves of this system show two rate regions. The change in rate occurs at ca. 40% conversion. Second-stage nucleation leads to a faster rate and consequently to a bimodally dispersed latex. The particle size distribution is relatively narrow before 40% conversion. The bimodally dispersed latex shows a bimodal molecular weight distribution in gel permeation chromatography and the results from fractional "creaming" of the latex indicate that the small-size particles contain the higher-molecular-weight polymer.
Novel polymerizable surfactants: synthesis and application in the emulsion polymerization of styrene
Polymer Journal, 2010
A series of anionic maleic surfactants were synthesized, and their chemical structures were characterized by NMR. The synthesized surfmers were then used in emulsion polymerization of styrene in the presence of potassium persulfate as an initiator. The polymerization kinetics were investigated, and the obtained latex particles were characterized in terms of particle size and size distribution. The results obtained were compared with the emulsion polymerization of styrene in the presence of an SDS surfactant. The influences of the nature and concentration of surfmers on polymerization conversion and particle size in particular were investigated and discussed.
The effect of vinyl benzyl chloride on emulsion polymerization of styrene
Polystyrene latexes were prepared, in the presence of, vinyl benzyl chloride (VBC) monomer. These particles were synthesized in surfactant-free batch radical emulsion polymerization of styrene and VBC monomer mixture, with 2,2'azobis(2-amidino propane)di-hydrochloride (V50) initiator. The polymerization kinetics was found to be rapid, as a function of VBC monomer concentration in the polymerization recipe. It is interesting to notice that high VBC amount leads to marked coagulum formation. The final hydrodynamic particle size was found to be slightly sensitive to the VBC concentration in the investigated range. The presence of VBC at the surface of the particles was investigated by XPS analysis. Unauthenticated Download Date | 3/6/15 12:35 PM
The effects of electrolyte concentration in the emulsion polymerization of styrene
Polymer, 1982
Using concentrations below that required to coagulate the latex, the effects of the addition of potassium chloride on the emulsion polymerization of styrene have been investigated. When potassium decanoate (an emulsifier with a high critical micelle concentration (c.m.c.)) is used the increase in the concentration of micellar emulsifier and the decrease in the area occupied by an emulsifier molecule at the polymer/water interface are significant. When this is taken into account Gardon's equation for latex particle size reproduces the trend of the experimental results at the lower electrolyte concentrations. The agreement can be made quantitative by choosing alternative values for the propagation rate constant of styrene and the rate of radical formation from persulphate. With potassium octadecanoate (which has a low c.m.c.) and with potassium decanoate at the higher electrolyte concentrations these factors cannot account for the results observed.
Journal of Applied Polymer Science, 2005
Batch emulsion copolymerization of vinyl acetate and 2-ethyl hexyl acrylate (VAc/2EHA = 90 : 10) was initiated by the thermal initiators ammonium persulfate and potassium persulfate at 70°C in the presence of nonylphenol ethoxylates with varying chain lengths and poly(vinyl alcohol). VAc–2EHA copolymer latexes were synthesized as two different series in a loop reactor. The first series was initiated by ammonium persulfate, and the second series was initiated by potassium persulfate. The influence of the counterions or initiators and chain lengths of a nonionic emulsifier on the properties of VAc–2EHA copolymer latexes were determined by measuring the viscosities, weight-average molecular weights, number-average molecular weights, molecular weight distribution, and surface tension of latexes to air. The results for the copolymer latexes indicated that some of their physicochemical properties increased with increasing chain length of the nonionic emulsifier, but some of them followed a different trend for the two initiators. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1380–1384, 2005
Spektra: Jurnal Fisika dan Aplikasinya
A series of experiments have been carried out and reported. This report describes the stages of the polymerization reaction during emulsion Polyvinyl Acetate (PVAc) synthesis. PVAc was synthesized from the Vinyl Acetate Monomer (VAM) with Ammonium Peroxydisulphate (APS) as an inorganic thermal initiator in the aqueous media under reaction temperature was keep at 65 until 75oCs by agitation speed was 300 rpm respectively during 4 hours of reaction time. The protective colloid agents and several types of surfactants were added to improve the obtained emulsion PVAc performance. The polymerization reaction was carried out without the addition of a protective colloid agent. The surfactants were produced the emulsion PVAc with the properties of solid content 0.89%, density 1.02 g/ml, viscosity 0.0033 Poise, pH 2.8, conductivity 12 ms, respectively. While the polymerization reaction involved protective colloid agents by using Polyvinyl Alcohol (PVOH) was obtained properties of emulsion PVA...
Die Angewandte Makromolekulare Chemie, 1998
Amphiphilic block and graft copolymers with polysiloxane and poly[(acetylimino)ethylene] sequences were used as nonionic surfactants in the emulsion polymerization of some vinyl monomers (styrene, methyl methacrylate, butyl methacrylate). The peculiarities of the systems (polymerization kinetics and emulsion characteristics) were related to the structural features of the studied emulsifiers and suggested their ability to participate in initiation and transfer reactions and respectively clouding phenomena in aqueous phase. ZUSAMMENFASSUNG: Block-und Pfropfcopolymere mit Polysiloxan-und Poly(acetyliminoethylen)-Bestandteilen wurden als nichtionische Emulgatoren bei der Emulsionspolymerisation von einigen Vinylmonomeren (Styrol, Methylmethacrylat, Butylmethacrylat) benutzt. Die Polymerisationssysteme (kinetische Aussagen, Teilchengröße, Teilchengrößenverteilungen, usw.) wurden charakterisiert und die Emulgatorstruktur-Polymerisationseigenschaft-Beziehungen wurden untersucht. Die Teilnahme der Copolymeren an der Initiierungs-und Ü bertragungsreaktion wurde festgestellt.
Turkish Journal of Chemistry
The copolymers of triethoxyvinylsilane (TEVS) with styrene (St), butyl acrylate (BA), and methacrylic acid (MAA) were prepared by emulsion polymerization. The copolymerization was carried out by using auxiliary agents at 90 • C in the presence of potassium peroxodisulfate (KPS) as the initiator. Nonylphenol ethylene oxide-40 units (NP-40) and sodium lauryl sulfoacetate (SLSA) were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized by Fourier transform infrared spectroscopy (FTIR). Thermal properties of the copolymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by optical microscopy (OM) and then the effects of temperature, agitation speed, initiator and silicone concentrations on the properties of the silicone-containing St/BA/MAA emulsion copolymers were discussed. The obtained copolymers have high solid content (50%) and can be used in emulsion paints as a binder. The monomer conversion and monomer conversion versus time histories indicate that by increasing the TEVS concentration the polymerization rate decreases.