Polyvinyl surface

Liquid or solid films which reduce or prevent adhesion between surfaces solid-solid, solid-paste, solid-liquid. Waxes, metallic soaps, glycerides (particularly stearates), polyvinyl alcohol, polyethene, silicones, and fluorocarbons are all used as abherents in metal, rubber, food, polymer, paper and glass processing. 

In the present work it was studied the dependence of analytical characteristics of the composite SG - polyelectrolyte films obtained by sol-gel technique on the content of non-ionic surfactant in initial sol. Triton X-100 and Tween 20 were examined as surfactants polystyrene sulfonate (PSS), polyvinyl-sulfonic acid (PVSA) or polydimethyl-ammonium chloride (PDMDA) were used as polyelectrolytes. The final films were applied as modificators of glass slides and pyrolytic graphite (PG) electrode surfaces. 

Lucie, S., Kovacevic, V., Packham, D.E., Bogner, A., Gerzina, A., Stearate-modified calcium carbonate fillers and their effect on the properties of polyvinyl acetate, composites. Proc. 2nd Int. Symp. Polymer Surface Modification Relevance to Adhesion, Newark, NJ, 24-26 May, 1999. 

The wet deck or surface, is the heart of most cooling towers. Generally, it takes the form of PVC (polyvinyl chloride) plastic film type surface. Water is made to spread out on this surface maximizing it s contact area with air to encourage evaporation. It consists of individual vacuum formed sheets with proprietary patterns of ridges. 

A low acid polyvinyl butyral-based pretreatment primer ( etch or wash primer are alternative names) is usually advantageous as the first treatment of a metal-sprayed surface before painting. Up to an equal volume of spirit soluble phenolic resin is used as a diluent to the polyvinyl butyral of conventional pretreatment primers. This has an incidental, but particularly valuable effect, in reducing the free acid available to penetrate into the pores of the coating. The modified pretreatment primer is highly water resistant and this helps to avoid damage due to condensation. 

Etch primers partially fulfil the roles of both pretreatment and primer. They contain phosphoric acid for surface passivation and are based on polyvinyl butyral ... 

The use of coatings applied in the form of tape is also increasing. Polyethylene and polyvinyl chloride films, either self adhesive or else supporting films of butyl adhesive, petrolatum or butyl mastic are in use as materials applied cold at ambient temperatures. Woven glass fibre or nylon bandage is also used to support films of filled asphalt or coal tar and these are softened by propane gas torches and applied to the steel surface hot, cooling to form a thick conforming adherent layer. 

Direct measurements on metals such as iron, nickel and stainless steel have shown that adsorption occurs from acid solutions of inhibitors such as iodide ions, carbon monoxide and organic compounds such as amines , thioureas , sulphoxides , sulphidesand mer-captans. These studies have shown that the efficiency of inhibition (expressed as the relative reduction in corrosion rate) can be qualitatively related to the amount of adsorbed inhibitor on the metal surface. However, no detailed quantitative correlation has yet been achieved between these parameters. There is some evidence that adsorption of inhibitor species at low surface coverage d (for complete surface coverage 0=1) may be more effective in producing inhibition than adsorption at high surface coverage. In particular, the adsorption of polyvinyl pyridine on iron in hydrochloric acid at 0 < 0 -1 monolayer has been found to produce an 80% reduction in corrosion rate . 

Quite naturally, novel techniques for manufacturing composite materials are in principal rare. The polymerization filling worked out at the Chemical Physics Institute of the USSR Academy of Sciences is an example of such techniques [49-51], The essence of the technique lies in that monomer polymerization takes place directly on the filler surface, i.e. a composite material is formed in the polymer forming stage which excludes the necessity of mixing constituents of a composite material. Practically, any material may be used as a filler the use of conducting fillers makes it possible to obtain a composite material having electrical conductance. The material thus obtained in the form of a powder can be processed by traditional methods, with polymers of many types (polyolefins, polyvinyl chloride, elastomers, etc.) used as a matrix. 

FIG. 40 Antistatic effect of alkanesulfonates in rigid polyvinyl chloride (tin-stabilized). Surface resistance according to DIN 53 482. Test specimen I-mm milled sheets, stored for 1 day at 23°C and 50% relative humidity. 

Here, the structures of interfacial water at a fused quartz surface with and without contact of polyvinyl alcohol (PVA) were investigated by in situ SFG spectroscopy and their role in low friction between PVA and a fused quartz surface is discussed. 

Polyvinyl chloride cylinders -1- nylon gauze -1- device for continuous water supply Soil slices at measurable distance from soil-root interface. High bulk density of soil sampled. Nutrient uptake through an induced root hairs surface. Study of rhizosphere effect over a time and distance gradient from the soil-root interface. 47, 67, 127-129... 

Polyvinyl chloride has been modified by photochemical reactions in order to either produce a conductive polymer or to improve its light-stability. In the first case, the PVC plate was extensively photochlorinated and then degraded by UV exposure in N2. Total dehydrochlorination was achieved by a short Ar+ laser irradiation at 488 nm that leads to a purely carbon polymer which was shown to exhibit an electrical conductivity. In the second case, an epoxy-acrylate resin was coated onto a transparent PVC sheet and crosslinked by UV irradiation in the presence of both a photoinitiator and a UV absorber. This superficial treatment was found to greatly improve the photostability of PVC as well as its surface properties. 

Gravimetric hoppers feed a mold with a prescribed weight of polymer. The feed stock is either a finely divided powder or a liquid plastisol. A plastisol is a suspension of a resin powder, typically polyvinyl chloride, in a plasticizer, used to manufacture. Rotational molders use liquids and powders in their process since both flow freely. This property permits the easy addition of the materials to the mold. More importantly, they flow smoothly around the interior of the mold as it rotates. In doing so, they coat the entire surface. 

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