| Glossary T-Z |
| Tt TDI Toluene di-isocyanate. Thermal cracking Thermal cracking is a petroleum refining process used to break up heavy oil molecules into lighter, more valuable fractions (e.g. gasoline, kerosene) by the use of high temperature without the aid of catalysts. It is used to convert gas oils into naphtha. Thermoplastic A plastic which is solid when cold, but which may flow and be re-formed multiple times with the application of heat. Some plastics are dissolved in solvents such as water (a latex) to aid their application. Thermoset Thermosets are a type of plastic that is the reaction product of two or more chemical compounds. While reacting and while still in a liquid shape thermoset plastics are moulded to form a wide variety of parts. Once the reaction is complete, thermoset plastics form durable solid articles (they "set"). Unsaturated polyester resins that are used to make glass reinforced plastics are an example of a thermoset plastic. Toluene Toluene, a colourless liquid, is an aromatic hydrocarbon used extensively as starting material for the manufacture of industrial chemicals. Its major end-products are polyurethanes. Uu Unsaturated polyester resins (PES, uPES, UPR or USPE) Unsaturated polyester resins are durable, resinous polymers. They are used over a broad spread of industries, mainly the construction, boat building, automotive and electrical industries. In most applications they are reinforced with small glass fibres - hence these plastics are commonly referred to as GRP or Glass Reinforced Plastics. uPES See Unsaturated polyester resins. UPR See Unsaturated polyester resins. Vv VOC See Volatile Organic Compound Volatile Organic Compound (VOC) The term "Volatile organic compounds" refers to organic compounds that readily evaporate. VOCs include pure hydrocarbons, partially oxidised hydrocarbons, and organic compounds containing chlorine, sulphur or nitrogen. They are widely used as fuels (e.g., propane and gasoline), as paint thinners and solvents, and in the production of plastics. VOC emissions have to be carefully controlled so as not to contribute to air toxicity and urban smog. Xx XPS See Extruded polystyrene. Xylene Xylene, a colourless liquid, is an aromatic hydrocarbon of which there are several forms. Xylenes are used as solvents, as components of aviation fuel, and as raw materials for the manufacture of dyes, fibres and films. Of the different forms of xylenes, paraxylene is commercially the most important. Back to Home Page |