Polyvinyl chloride dispersion plastic

The suspension polymerisation approach is often used in the production of polyvinyl chloride dispersions for use in plastic pipes. Polystyrene and styrenic copolymers are also produced by suspension polymerisation. The polystyrene beads are often prepared by suspension polymerisation for use as packing material in gel permeation chromatography (GPC) columns. Ion exchange resin beads are also commonly produced by suspension polymerisation. Because suspension beads are relatively large, it is easier to separate the polymer by coagulation than in the case of emulsion polymerisation. 

Because plasticized PVC is compounded of a polyvinyl chloride dispersion of high molecular weight vinyl chloride polymers in a suitable liquid plasticizer, formulations can be made for special applications. By selective compounding, both physical and corrosion resistant properties can be modified. For certain applications this feature can be most advantageous. 

Chromatograms can be made handleable and storable by treatment with plastic dispersions, based on polyacrylic ester, polyvinyl chloride or polyvinyl propionate, such as, for example, Neatan (Merck) [21 — 23]. In order to avoid clogging the spray head with plastic dispersion residue it is recommended that it be rinsed through immediately after use with tetrahydrofuran or that disposable jets be employed [24]. 

Gas-filled plastics are polymer materials — disperse systems of the solid-gas type. They are usually divided into foam plastics (which contain mostly closed pores and cells) and porous plastics (which contain mostly open communicating pores). Depending on elasticity, gas-filled plastics are conventionally classified into rigid, semi-rigid, and elastic, categories. In principle, they can be synthesized on the basis of any polymer the most widely used materials are polystyrene, polyvinyl chloride, polyurethanes, polyethylene, polyepoxides, phenol- and carbamideformaldehyde resins, and, of course, certain organosilicon polymers. 

Another very important property of plasticizers for PVC resins is the ability to act as a dispersing medium for polyvinyl chloride plastisols. The performance of the particular plasticizer in a plastisol application depends to a great extent on a property known as its viscosity stability. The stability of the plastisol to viscosity build up is the manifestation of the solvating effects of the plasticizer, and thus, those materials with higher solvating efficiency tend to display an increase in plastisol viscosity on standing. Figure 3 is the plot of the viscosity stability of PVC o-phthalate ester plastisol compositions and, in essence, compares the alcohol-derived plasticizers with that of the olefin-derived plasticizer. The data show that... 

As the shear rate increases, the viscosity of some dispersions actually increases. This is called dilatancy, or shear-thickening. Dilatancy can be due to the dense packing of particles in very concentrated dispersions for which at low shear, the particles can just move past each other but at high shear they become wedged together such that the fluid cannot fill (lubricate) the increased void volume, and the viscosity increases. An example of this effect is the apparent drying of wet beach sand when walked on, the sand in the footprint initially appears very dry and then moistens a few seconds later. Other examples include concentrated suspensions (plastisols) of polyvinyl chloride (PVC) particles in plasticizer liquid and the commercial novelty product Silly Putty (which is a silicone material). 

Polyvinyl chloride Rigid PVC Plasticized PVC Dry blends Liquid or paste dispersions Intensive high-speed mixers Roll mills or disk Impeller mixers... 

Vinyl dispersions are fluid suspensions of special fine particle size polyvinyl chloride resins in plasticizing liquids. When the system is heated to about 350F., fusion (mutual solubilization of resin and plasticizer) takes place. The dispersion turns into a homogeneous hot melt. When the melt is cooled below 140F., it becomes a tough vinyl coating with excellent physical properties such as flexibility, abrasion resistance, chemical resistance and excellent aging. 

Use Solvent for resins, acetylene, etc., pigment dispersant, petroleum processing, spinning agent for polyvinyl chloride, microelectronics industry plastic solvent applications, intermediate. 

Recently, so-called plastisol fabricating techniques have been developed which allow the cheap and efficient manufacture of many articles from polyvinyl chloride. Plastisds ere dispersions of pdyvinyl chloride in appropriate solvent mixtures or in plasticizers. Molds are either coated by... 

One large-scale use of this process is in the production of synthetic rubber and, on a small-scale, in the production of polyvinyl chloride (PVC) and polystyrene. The other large-scale use is in the production of plastics dispersions used as such (without first coagulating them) for the production of paints, pigments, inks, coatings, and adhesive paste (e.g., polyvinyl acetate, polyvinyl propionate, and polyacrylic ester dispersions). 

A polyvinyl chloride plastisol is a dispersion of very fine particle size polyvinyl chloride in a plasticizer. 

Polyvinyl Chloride. In plastisol processing, PVC is dispersed in hquid plasticizer then fused to a sol and cooled to a gel to produce rubbery products. When the processor wants to decrease the plastisol viscosity without excessive softening of the final product, he uses a polymerizable plasticizer such as a glycol diacrylate (Fig. 3.71) plus a little peroxide. The plasticizer gives a more fluid plastisol, and then, during hot fusion, the peroxide crosslinks the plasticizer to prevent excessive plasticization of the finished product. 

Water-based dispersions or emulsions such as polyvinyl acetate, acrylics, polyvinyl chloride and polyvinyl alcohol with plasticizers and tackifiers. In addition, this range can include urea formaldehyde and phenolic adhesives, resins, natural adhesives produced from starch, dextrin, casein, animal glues (see Polyvinyl alcohol in adhesives, Phenolic adhesives single-stage resoles. Phenolic adhesives two-stage novolacs. Animal glues and technical gelatins) and rubber latex (see Emulsion and dispersion adhesives). Solvent-free 100% solids such as polyurethane. Hot melt adhesives include Ethylene-vinyl acetate copolymers, polyolefins, polyamides, polyesters with tackifiers and waxes. More recent additions include cross-linkable systems. 

A plastisol is a liquid dispersion of a fine-particle-size polyvinyl chloride in a plasticizer. PVC linings are commonly called vinyls. They are noted for their toughness, chemical resistance, and durability. They are available as solutions, dispersions, and lattices. PVC powders have essentially the same properties as liquids. Polyvinyl chloride plastisol and powder coatings have limited adhesion and require primers. These linings must be heat cured. 

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