Vinyl polymers dispersion resins

Polymers. In combination with various metal salts, sorbitol is used as a stabilizer against heat and light in poly(vinyl chloride) (qv) resins and, with a phenohc antioxidant, as a stabilizer in uncured styrene—butadiene mbber (qv) compositions and in polyolefins (see Heat stabilizers Olefin POLYMERS Rubbercompounding). Heat-sealable films are prepared from a dispersion of sorbitol and starch in water (255). Incorporation of sorbitol in coUagen films gready restricts their permeabiUty to carbon dioxide (256). 

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The pastes used are plastisols—finely divided polymer dispersed in plasticizer. They are mobile mixtures which may range in viscosity from liquids that can be poured readily to thick pastes—the viscosity depending essentially on the type of resin and the amount and type of plasticizer involved. Such mixtures can be applied to substrates by coating or by techniques akin to printing after application they are converted into homogeneous flexible vinyls by heating to temperatures in the range 175 to 200 °C, when the dispersed particles of resin dissolve in the plasticizer and are fused into a continuous structure.1... 

Figure 2 shows typical steps in the manufacture of an emulsion resin. Basically, the vinyl chloride monomer is added to a pressure vessel (reactor) where in contact with the emulsifier and the initiator the polymerization is carried out under conditions of controlled pressure and temperature. Since it is uneconomical to carry out the reaction to 100% conversion, unreacted monomer is removed in a stripping vessel. If the polymer is to be applied via the latex (water-based coating) technique, the manufacturing process can now be considered complete. If a dispersion resin is to be produced, then latex from the blend tank is transferred to a spray dryer where water is removed. These very small polymer particles... 

Goi touch. [BFGoo ich/Spec. Polymers] Vinyl dispersion resin specialty polymer for high-performance vinyl or latex disposable gloves. 

Using a mixture of castor oil and hydroxyether of bisphenol-A (HBA) as the polyol and reacting with TDI in the presence of DBTDL catalyst at 35°C, a series of polyurethanes are prepared in an air-circulating oven for 48 h. A series of poly(urethane urea)-vinyl polymer hybrid aqueous dispersions are prepared. Waterborne poly(urethane urea) is synthesised from castor oil and polyoxypropylene polyol M = 1000 g moL ), dimethylol propionic acid and isophorone diisocyanate and then neutralised with tertiary amine. The hybrid aqueous dispersion with high oil content poly(urethane urea) exhibits excellent compressive mechanical strength. Sunflower oil-modified waterborne polyurethane resin may also be prepared. The waterborne resin is synthesised from the monoglyceride of the oU, poly(propylene-ethylene) triol, tartaric acid and toluene diisocyanate, then neutralised with triethyl amine. 

Latex la- teks [NS latic. latex, from L. fluid] (1835) (pi lattices or latexes) n. (1) An emulsion of a polymeric substance in an aqueous medium. (2) The sap of the hevea (rubber) tree and other plants, or emulsions prepared from the same. Latices of interest to the coatings and plastics industry are based mainly on styrene-butadiene co-polymers, polystyrene, acrylics, and vinyl polymers and co-polymers. (3) Fine dispersion of rubber or resin, natural or synthetic, in water the synthetic is made by emulsion polymerization. Latex and emulsion are often used synonymously in the paint industry. Emulsified monomers once polymerized become solids or plasticized gel particles and not emulsions but aqueous suspensions. Lovell PA, El-Aasser MS (eds) (1997) Emulsion polymerization and emulsion polymers. John Wiley and Sons, New York. Martens CR (1964) Emulsion and water-soluble paints and coatings. Reinhold Publishing Co., New York. VanderhofF JW, Gurnee EE (1956) Motion picture investigation of polymer latex phenomena. TAPPI 39 (2) 71-77. VanderhofF JW, Tarkowski HL, Jenkins MC, Bradford EG (1966) Theoretical considerations of the interfacial forces involved in the coalescence of latex particles. J Macromol Chem 1 (2) 361-397. 

Environmental restrictions are affecting both the pigments and the media that can be used. Special interest attaches to water-based paints, often selected to avoid the problems associated with solvents. In all polymer dispersions used as a vehicle for water-dilutable paint products, the polymer (generally an acrylic resin, sometimes copolymerized with styrene or a vinyl... 

The particles are hexagonal platelets which tend to stack together producing larger particles. Surface treatment is needed to facilitate dispersion in a resin. The surface treatment can have side-effects, inhibiting reaction with epoxy and vinyl polymers. The particles are rendered hydrophobic by suitable treatment, for achieving low dielectric loss. Very fine kaolin particles can increase rather than decrease the strength of certain thermoplastics. 

Alkyd paints dominated the architectural coating market for a long period until the appearance of polymer dispersions or the so-called latex paints. Specifically for wall application waterborne paints based on poly(vinyl acetate) homo- and copolymers, styrene-acrylics and pure acrylic latexes almost completely took over the market from the alkyd resins for both interior and exterior application. However, for... 

Another class of solvent-based dispersion is the organosols. In this case, vinyl chloride copolymer resins are dispersed in suitable nonvolatile plasticizers and solvent. The solvent is evaporated and the remaining film is heated to approximately 177 °C. The heat helps dissolve the resin in the plasticizer, and a tough, flexible film is obtained upon cooling to room temperature. The major polymers used for solvent-based adhesives are listed in Table 8.10. 

Uses Emulsifier, surfactant in emulsion polymerization of vinyl chloride and vinyl acetate, suspension polymerization of vinyl chloride dispersant for resins, pigments, polymers, and dyes in org. systems pigment dispersant in printing inks mst preventive food-pi, adhesives, paper/paperboard emulsifier in mfg. of food-contact artides... 

Suspension polymerization of VDE in water are batch processes in autoclaves designed to limit scale formation (91). Most systems operate from 30 to 100°C and are initiated with monomer-soluble organic free-radical initiators such as diisopropyl peroxydicarbonate (92—96), tert-huty peroxypivalate (97), or / fZ-amyl peroxypivalate (98). Usually water-soluble polymers, eg, cellulose derivatives or poly(vinyl alcohol), are used as suspending agents to reduce coalescence of polymer particles. Organic solvents that may act as a reaction accelerator or chain-transfer agent are often employed. The reactor product is a slurry of suspended polymer particles, usually spheres of 30—100 pm in diameter they are separated from the water phase thoroughly washed and dried. Size and internal stmcture of beads, ie, porosity, and dispersant residues affect how the resin performs in appHcations. 

Suspension Polymerization. At very low levels of stabilizer, eg, 0.1 wt %, the polymer does not form a creamy dispersion that stays indefinitely suspended in the aqueous phase but forms small beads that setde and may be easily separated by filtration (qv) (69). This suspension or pearl polymerization process has been used to prepare polymers for adhesive and coating appHcations and for conversion to poly(vinyl alcohol). Products in bead form are available from several commercial suppHers of PVAc resins. Suspension polymerizations are carried out with monomer-soluble initiators predominantly, with low levels of stabilizers. Suspension copolymerization processes for the production of vinyl acetate—ethylene bead products have been described and the properties of the copolymers determined (70). Continuous tubular polymerization of vinyl acetate in suspension (71,72) yields stable dispersions of beads with narrow particle size distributions at high yields. 

Resins with high vinyl acetate content (ca. 60-90%) are very often emulsions or dispersions in water used for modification of other polymers, and carriers for plastic and rubber... 

Dispersed phase polymerisation of HIPEs has also been used to prepare polymer-supported quaternary onium phase transfer catalysts [162]. One strategy involved the polymerisation of a concentrated emulsion of vinyl benzyl chloride (VBC) in water and subsequent quaternisation of the polymer resin with tertiary amines and phosphines (Fig. 22). 

The first successful static firing of plastisol propellant took place late in 1950 as part of a broad program conducted by Atlantic Research Corp. to investigate and evaluate plastisol propellants and methods for their manufacture (16). Major attention was directed to poly (vinyl chloride), cellulose acetate, and nitrocellulose, although other polymers were tested for their suitability (17). Patent applications were filed for plastisol propellant compositions and manufacturing processes, based on poly(vinyl chloride) (PVC) (19) and on nitrocellulose (18). The commercial availability of dispersion grade PVC enabled work with this resin to advance rapidly. The balance of this paper is devoted to a discussion of PVC plastisol propellants and their manufacture. 

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