Glossary of Terms

Acetal: a linear polymer consisting of unbranched polyoxymethylene chains

Acid: a substance that produces hydrogen ions in solution

Acrylic: a synthetic resin prepared from acrylic acid or from a derivative of acrylic acid

Addition Reaction: polymerization of monomers by a chain mechanism involving active centers on the growing chains

Alkalies: salts or mixtures which neutralize acids

Amino Resins: urea and melamine formaldehyde; containing an -NH₂ or -NH group

Amorphous: a substance with considerable disorder in its structure

Base: a substance that produces hydroxide ions in aqueous solution

Cellulose: a naturally occurring polysaccharide made up solely of glucose units

Cellulosics: plastics which are derived from cellulose, containing various substituted chemical groups

Condensation Reaction: polymerization of monomers in which two or more molecules combine, resulting in the production of water or some other simple substance

Crystalline: a solid with a regular arrangement of its components

Filler: an inert substance added to a plastic to improve its hardness, stiffness, and impact strength

Homopolymer: a polymer consisting of only one monomeric species

Hydrocarbon: a compound composed of carbon and hydrogen

Hydroxy: an OH group within a molecule

Monomer: a simple compound which can react to form a polymer; the basic repeating unit of a polymer

Oxidizing Agent: a reactant that accepts electrons from another reactant

Phenolics: a synthetic resin produced by the condensation of an aromatic alcohol with an aldehyde in base

Polyamides: a polymer in which the structural units are linked by amide or thio-amide groupings

Polyesters: a polymer formed by the reaction between a dibasic acid and a dihydroxy alcohol, both organic, or by the polymerization of a hydroxy carboxylic acid

Polymer: a high molecular-weight organic compound, natural or synthetic, whose structure can by represented by a repeated small unit

Polyolefins: polymers composed of unsaturated hydrocarbons, extracted from petroleum or natural gas

Polyurethane: a polymer produced by reacting diisocyanate with organic compounds containing two or more active hydrogens to form polymers having free isocyanate groups

Resin: the polymeric starting material for plastics

Rubber: an elastomer capable of rapid elastic recovery after being stretched

Salt: an ionic compound

Solvent: a substance (usually a liquid) which dissolves other substances

Styrene: a plastic made by the polymerization of styrene with other unsaturated compounds

Synthetic: materials that are human-made

Thermoplastic: a plastic which is capable of being repeatedly softened by heat and hardened by cooling

Thermoset: a plastic which has undergone a chemical reaction by the action of heat, catalysts, ultraviolet light, leading to a relatively infusible and cross-linked state

Vinyl Halides: a plastic formed by the polymerization of chemical compounds containing the group CH₂=CH—