Water-expandable polystyrene

POLYMERIC BEADS, EXPANDABLE (POLYSTYRENE or POLYSTYRENE BEADS, EXPANDABLE) (9003-53-6) (CgHg), (flash point 644 to 662°F/340 to 350°C autoignition temp 801°F/427°Cf "l). Incompatible with strong oxidizers, hydrocarbon solvents. Decomposes above 572°F/300°C, producing toxic styrene, benzene, carbon monoxide, and other hydrocarbon fumes. On small fires, use alcohol-resistant foam, dry chemical powder, water spray, or CO extinguishers. Note This material may be shipped in a flammable solvent. Check MSDS and refer to solvent carrier. 

Shen, J., Cao, X., and Lee, L. J., 2006. Synthesis and foaming of water expandable polystyrene-clay nanocomposites. Polymer 47 6303-10. 

Alkanesulfonates, mostly in combination with other surfactants, can also be used to provide an antistatic effect on expandable polystyrene. Even after foaming up of the polystyrene pearls, such as with water, the antistatic effect is retained [90],... 

Suspension Polymerization. Water is the suspending phase. Inorganic salts and vigorous agitation prevent coalescence and agglomeration. The reaction mode is batch. The largest use of suspension polymerization is for the manufacture of expandable polystyrene beads. 

In order to determine the sources of contamination, some water samples, including wastewaters and effluents from different industries were also sampled. Along the Cinca River and in the industrial area of Monzon, industrial effluents from two different industries were selected the first one produced EPS (Expandable polystyrene) treated with flame retardants and ABS (Acrylonitrile-butadiene-styrene), and the second one produced PVC (Polyvinyl chloride). As regards the Vero River, three industries were sampled the first one, a textile industry which produced polyester fibers treated with flame retardants, the second one produced epoxy... 

While unaffected by water, styrofoam is dissolved by many organic solvents and is unsuitable for high-temperature applications because its heat-distortion temperature is around 77°C. Molded styrofoam objects are produced commercially from expandable polystyrene beads, but this process does not appear attractive for laboratory applications because polyurethane foams are much easier to foam in place. However, extruded polystyrene foam is available in slabs and boards which may be sawed, carved, or sanded into desired shapes and may be cemented. It is generally undesirable to join expanded polystyrene parts with cements that contain solvents which will dissolve the plastic and thus cause collapse of the cellular structure. This excludes from use a large number of cements which contain volatile aromatic hydrocarbons, ketones, or esters. Some suitable cements are room-temperature-vulcanizing silicone rubber (see below) and solvent-free epoxy cements. When a strong bond is not necessary, polyvinyl-acetate emulsion (Elmer s Glue-All) will work. 

This simplification was used by Ottewill and Walker (7) in their study of the adsorption of a nonionic surfactant onto polystyrene latex in aqueous sodium chloride. In the case of carboxylated emulsion polymers, evidence from conductometric titrations suggests that the carboxyl groups are generally concentrated near the particle surface. The resultant model of an expanded particle is that of a hydrated acid-rich shell surrounding a compact polymer core. The hydrated shell may be viewed as a dilute polymer solution where the density is close to that of water, i.e., Pe= P0. With this assumption, Equation 1 reduces to the form ... 

Water or other nonsolvent Polymer or polymer in solution Suspension, dispersion, or emulsion polymerization Emulsion polymerization of a rubber latex. Suspension polymerization of expandable polystyrene... 

While starch copolymers are typically prepared by batch polymerization methods, reactive extrusion of starch has been studied. Mixtures of starch, polystyrene, styrene, sodium hydrogen carbonate, citric acid and water were extruded at temperatures between 100°C and 200°C.118 It was reported that expanded graft copolymers... 

Mixed Polymers. A mixture of 5 parts of polyethylene and 95 parts of expandable polystyrene is extruded and converted to quenched pellets. The pellets are expanded and converted into molded foams with improved resistance to solvents and water vapor transmission (29). There is a polyethylene skin on the surface. 

Most expandable polystyrene processes involve aqueous suspension systems in which pentane fractions of petroleum are introduced before, during, or after polymerization of styrene. Water-free systems may also be used. Particle size is controlled by suspension polymerization or by chopping fine filaments. The quenched pellet process for expandable polystyrene can consume off-size particles and is a convenient way to add colorants and cell-nucleating additives. 

Foams Wave by Mater-Bi, foamed sheet packaging is a biodegradable alternative to conventional protective foam packaging such as polystyrene, polyurethane and polyethylene. Wave by Mater-Bi is starch-based, and is expanded using water, extruded into sheets and then assembled into blocks that can be cut into any shape. The foams have a robust and resilient closed-cell structure. 

Foams are closely related to emulsions. In foams, the dispersed phase is not an oil or water, but it is a gas. One can use similar techniques for making foam and for making emulsions, and some of the properties are comparable. Foams are ubiquitous as well of course, the foam on beer is well known, but bread is a foam as well, as are ice cream, whipped cream, expanded polystyrene or styrofoam (which is a solid polymeric matrix with a large volume fraction of gas bubbles in it), and polyurethane foam, used, for example, for making mattresses. 

Living radical dispersion polymerization is a promising way to expand the design and scope of functional polymer colloids to a wider range of other monomers. The 2,2,6,6-tetramethyl-l-piperidinyloxy (TEMPO)-mediated living radical dispersion polymerization of styrene has been carried out in presence of PS-h-P(PP-aZt-E) in decane at 135 °C [95] or PVP in alcohol-water at 130 °C [96] in order to produce microspheres with a very broad size distribution, consisting of relatively low molecular weight polystyrene (M =10 ) with M /Mn=l.l. 

This type of foam is available in two forms, extruded-polystyrene foam and expanded polystyrene for molded foams. Polystyrene foams are light, closed-cell foams with low thermal conductivities and excellent water resistance. They meet the requirements for low-temperature insulation and buoyancy media (6). 

Up to 1973 very little information had been published on these foams. France has produced polysulfone foams from expandable beads which resemble polystyrene beads in their processing. In a typical formulation 1- butene and sulfur dioxide are copolymerized in such a way that the copolymer contains excess unpolymerized 1-butene, which volatilizes to cause foaming. Water, ethyl hydroxyethyl cellulose, 1-butene, sulfur dioxide, and a solution of isoprophyl peroxydicaibonate in... 

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