Sulfur, pure plastic

Most molded plastics have a very smooth, hydrophobic surface that must be modified. Chemical etchants are used to oxidize and roughen the surface. The resultant hydrophilic surface promotes good metal-to-plastic adhesion. The etchant is usually a solution of chromic acid and sulfuric acid pure chromic acid can also be used. 

Titanium dioxide (E171, Cl white 6) is a white, opaque mineral occurring naturally in three main forms rutile, anatase, and brookite. More than 4 million tons of titanium dioxide are produced per year and it is widely used for industrial applications (paints, inks, plastics, textiles) and in small amounts as a food colorant. ° "° Production and properties — Titanium oxide is mainly produced from ilmenite, a titaniferous ore (FeTiOj). Rutile and anatase are relatively pure titanium dioxide (Ti02) forms. Titanium oxide pigment is produced via chloride or sulfate processes via the treatment of the titanium oxide ore with chlorine gas or sulfuric acid, followed by a series of purification steps. High-purity anatase is preferred for utilization in the food industry. It may be coated with small amounts of alumina or silica to improve technological properties. 

Rapidly quenched, pure elemental sulfur is extremely plastic (6) This plastic sulfur with its polymeric structure has tensile qualities lacking in the crystalline form, but... 

Pure S is heated to 250-350°C under a nitrogen blanket. A thin stream of the melt is then poured into a cylindrical vessel (at least 60 cm. high) which has a bottom inlet and top outlet for ice-water flow. Strands of plastic sulfur collect in the lower part while the flowers of sulfur forming on the water surface are continuously flushed away. 

As for pure elastomers, the vulcanization step provides sulfur bridges between elastomeric chains and connects them into an infinite network. Vulcanization is supposed to be mainly unaffected by the presence of the reinforcing fillers and transforms the roughly plastic green mixes into viscoelastic vulcanizates. 

The chemical composition of plastics is basically organic polymers. They have very large molecules composed of connecting chains of carbon (C), generally connected to hydrogen atoms (H) and often also oxygen (O), nitrogen (N), chlorine (Cl), fluorine (F), and sulfur (S). Thus, while polymers form the structural backbone of plastics, they are rarely used in pure form. In almost all plastics other useful and important materials are added to modify and optimize properties for each desired process and/or product performance application. 

Biodiesel can be used in its pure form (BlOO) or blended with petroleum diesel (a common blend is known as B20, a mixture of 80% petroleum diesel and 20% biodiesel). Biodiesel is not raw vegetable oil, but rather is a product derived from the oil. Biodiesel has a slightly lower fuel value than petroleum diesel, but has greater lubricity than current low sulfur diesel fuel. Biodiesel also has a higher flash point, and will gel at low temperatures of about -10 °C, making use in cold weather conditions difficult. Biodiesel is compatible with most parts in commercial diesel engine systems, and thus could almost be used as a drop-in replacement in trucks, buses, boats, and construction equipment. However, the difficulties associated with low-temperature operation and the potential degradation of plastic parts in the fuel system have made the B20 blend the typical fuel associated with biodiesel use. 

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