Poly compounding ingredients

ASTM D2151, Staining of poly(vinyl chloride) compositions by rubber compounding ingredients. 1995. 

ASTM D2151-95(2000) Standard Practice for Staining of Poly(Vinyl Chloride) Compositions by Rubber Compounding Ingredients... 

PVC. Poly(vinyl chloride) (PVC), a very versatile polymer, is manufactured by the polymerisation of vinyl chloride monomer, a gaseous substance obtained from the reaction of ethylene with oxygen and hydrochloric acid. In its most basic form, the resin is a relatively hard material that requites the addition of other compounds, commonly plasticisers and stabilisers as well as certain other ingredients, to produce the desired physical properties for roofing use. The membranes come in both reinforced and nonreinforced constmctions, but since the 1980s the direction has been toward offering only reinforced membranes. The membrane thickness typically mns from 0.8—1.5 mm and widths typically in the range of 1.5—4.6 m. 

In the massive form poly(vinyl chloride) is a colourless rigid material with limited heat stability and with a tendency to adhere to metallic surfaces when heated. For these, and other, reasons it is necessary to compound the polymer with other ingredients to make useful plastics materials. By such means it is possible to produce a wide range of products, including rigid piping and soft elastic cellular materials. 

Now that the ingredients are defined, the nature of vulcanization can be discussed. Vulcanization occurs through the cross-linking system. The system shown below is the system used by many major silicone sealant compounders around the world, to make high and medium modulus sealants. It consists of hydroxyl-ended poly-... 

The formulation of aqueous injectable suspensions follows, in general, the same lines that were e.stablished when drugs such as cortisone, penicillin, or pro-caine were first prepared in this form. The main ingredients are, in addition to the active compound, wetting agents and protective colloids. As in the case of reconslitutable suspensions, polysorbate 80 is most frequently used to decrease the solid-liquid interfacial tension, this promoting the sustitution of a solid-air interface by a solid-water one. Another surfactant that is often employed is siv dium poly succinate. 

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