Copolymer latex polymerization

Emulsion Polymerization. Poly(vinyl acetate) and poly(vinyl acetate) copolymer latexes prepared in the presence of PVA find wide appHcations in adhesives, paints, textile finishes, and coatings. The emulsions show exceUent stabiHty to mechanical shear as weU as to the addition of electrolytes, and possess exceUent machining characteristics. 

Abstract Emulsion homopolymers and copolymers (latexes) are widely used in architectural interior and exterior paints, adhesives, and textile industries. Colloidal stabihzators in the emulsion polymerization strongly affect not only the colloidal properties of latexes but also the fdm and mechanical properties, in general. Additionally, the properties of polymer/copolymer latexes depend on the copolymer composition, polymer morphology, initiator, polymerization medium and colloidal characteristics of copolymer particles. 

The butadiene and butadiene-acrylic monomer systems polymerize when irradiated on PVC or vinyl chloride copolymer latex. The structure of the polymer obtained may be grafted if it can be proved that the copolymer properties are different from the blend properties. To elucidate the structure we studied a copolymer obtained by polymerizing butadiene-acrylonitrile on a PVC homopolymer lattice. Owing to practical reasons and to exclude the secondary effect of catalytic residues we used y radiation. However, we shall observe in a particular case the properties of peroxide-initiated graft copolymer. 

No clear evidence was obtained about the alteration of the main reaction locus for the copolymerization of St with MA. This would be attributed to the difference in the partition coefficient between MA and AA (see above) and the difference in the number of latex particles formed in their copolymerization systems with St. (The number of particles in St-AA copolymer latex was about a third of that in St-AA latex. The small number for St-MA system is considered to result from the lower particle-stabilizing ability of MA due to its lower hydrophilicity.) These factors would alter the balance of the polymerization in two reaction loci, that is, the aqueous phase and the particles, and consequently serve to change the reaction mode. 

Preparation of Carboxylated Latexes. Latexes were prepared by emulsion polymerization using recipes given in Table I. Several MMA-MAA copolymer latex samples were prepared with differ-... 

Figure 5. Distribution of carboxyl groups in MMA-MAA copolymer latexes as weight percent based on the MAA content used in the polymerization (1) carboxyl groups in the serum (2) surface carboxyl groups (3) carboxyl groups next to the surface (4) carboxyl groups buried deeply (5) unneutralized carboxyl groups (A) batch-type latexes (B) semicontinuous-type latexes...

Inaba et al. prepared a series of model styrene/butyl acrylate copolymer latexes with glass transition temperatures at room temperature. The functional monomer 2-(3-isopropenylphenyl)-2-methylethylisocyanate (TMI) was used as monomer/crosslinking agent for further film formation. A small amount of methacrylic acid was introduced in some formulations in order to enhance the crosslinking reaction. A redox initiation system was used to reduce premature crosslinking during the polymerization [82]. 

Duracher D, Sauzedde F, Elaissari A, Perrin A, Pichot C (1998) Cationic amino-containing A-isopropyl acrylamide-styrene copolymer latex particles 1-particle size and morphology vs. Polymerization process. Colloid Polym Sci 276(3) 219-231... 

Fig. 29. Proton NMR spectrum of the copolymer latex (in CDC13) for a mole feed ratio of methacrylic acid to styrene of 0.12, internal phase ratio 0.93, AIBN 0.3 g, SDS 0.4 g and water 3 ml, polymerized first for 12 h at 40 °C. After this polymerization, additional water (twice as much as the weight of the emulsion) was added into the tubes, then polymerization continued for 2 days...

The object of this study was to clarify some aspects of the mechanism of shear-induced flocculation in colloidal dispersions. Vinyl chloride homopolymer and copolymer latices were prepared by emulsion polymerization using sodium dodecyl sulphate as emulsifier. Agglomeration behavior in these latices was studied by measuring the mechanical stability using a high speed stirring test. The latex particle size was measured by an analytical centrifuge. Molecular areas of emulsifier in the saturated adsorption layer at the surface of homopolymer and copolymer latex particles were estimated from adsorption titration data. 

After the paper making process is complete, latexes that are useful as binders for the application of clays or CaCC>3 to paper for printing paper may be prepared using the dimer of AMS. In a typical formulation, styrene, butadiene, Me methacrylate, and acrylonitrile were emulsion polymerized in the presence of AMS dimer to obtain a copolymer latex.473 Surprisingly, the AMS dimer was used in combination with tert-dodecylmercaptan, so there may have been some residual odor. Unsaturated carboxylic acids, such as acrylic acid, or sulfonic acids, such as 2-ethylsulfonyl acrylate, or unsaturated amides, such as acrylamide, are also useful, providing the polarity necessary in these applications.474... 

Riess G. Block copolymers as polymeric surfactants in latex and microlatex technology. Colloids Surf 1999 A 153 99-110. 

A latex-supported catalyst has been used to isolate sites. Styrene has been polymerized in the presence of an ionene diblock copolymer (a water-soluble cationic copolymer) to form a graft copolymer latex.31 The cobalt phthalocyanine sulfonate catalyst [CoPc(S03 Na+])4 was added and became attached to the cationic polymer. When this catalyst was used for the oxidation of thiols to disulfides by oxygen, the activity was 15 times that in a polymer-free system. 

Latexes—These are dispersions of homopolymers and copolymers in water that are produced by anionic emulsion polymerization and contain 50% solids. Particle size is low (0.2 ym) as is viscosity (20-30 centlpoises). To produce film forming properties, homopolymer latexes must be plasticized. They are supplied either with or without plasticizer. Certain copolymer latexes such as those with acrylates are self-plasticized and do... 

Use of ultrasound in latex polymerization of vinyl acetate copolymers [224]. 

Recently, a series of styrene-n-butyl acrylate copolymer latexes were prepared by conventional or miniemulsion polymerization techniques which incorporated TMI and/or methacrylic acid (MAA), and the interfacial crosslinking behaviour of films derived firom these latexes was investigated [33]. It was shown that crosslinking was dramatically enhanced in the presence of MAA. However, films prepared with TMI also crosslinked in the presence of atmospheric moisture with time at room temperature. This work also demonstrated the stability of... 

All latex samples prepared by emulsion polymerization are characterized by a broad distribution of molar masses, and in the case of copolymer latexes, a distribution of copolymer composition. Since the diffusion coefficient for a polymer depends upon both the chain length and the chemical structure, the polymers in any one film sample will be characterized by a rather broad distribution of Dcm values. Experiments to detormine in such systems actually yield a value averaged over the distribution, Dts. As will be seen below, since different components of the system contribute to the measured signal at different times, and the fastest diffusing species dominate the diffusion at early times, experi-mental values of Detr decrease with the ext t of interdiffiision. For such sanqiles, one is normally less int sted in the absoluie values of than in how extonal... 

Structure in VAc copolymer latex particles has been investigated in die past and continues to be an area of intense study. General areas of investigation are inadvertent structure, such as that caused by the difference in reactivi ratios and monomer solubili differences, and intentional structure, that produced by polymerizing monomers in a controlled manner to obtain the desired structured particles. 

Hazardous Decomp. Prods. CO, CO2, acrid fumes NFPA Health 2, Flammability 3, Reactivity 2 Uses Monomer for synthesis of nitrile rubber, PVAc emulsions, PVOH, EVA copolymers, vinyl chloride-vinyl acetate copolymers, PVBI, and vinyl acetate-acrylonitrile copolymers in polymerized form for plastic masses, films, lacquers, latex paints, adhesives, textile finishing, safety glass interlayers textile hand modifier binder for paper coatings esterification for food starch modified film-former in cosmetics food pkg. adhesives resinous/polymeric food-contact coatings for polyolefin films food-contact paper/paperboard, ionomeric resins, copolymers, laminates, resin-bonded filters, textiles... 

Uses Reactive intermediate for polymerization for copolymer latexes, water-sol. polymers, thermosetting coatings, adhesives, inks, textile sizing, emulsion paints Manuf./Distrib. Aldrich... 

Daxad 31 Daxad 32 Potassium polyaciylate Sodium polyisobutylene/ maieic anhydride copolymer dispersant, latex polymerization Daxad 34N10 Polyurethane prepolymer, Sodium dbuiyi naphStalene sulfonate Tergitol XD Teraltol XJ dispersant, latex trade sales paints Patcote 500 Tamol 1124 dispersant, lead silicate exterior latex paints... 

---