ABSTRACT
Many polymers used in the building trade are commonly referred to as plastics. A polymer is a chain of many hundreds of thousands of individual molecules. Polymerization is the process by which the individual monomers react chemically to form a polymer which exists in a state of lower free energy than the individual monomers. There are three fundamental categories of polymers: thermoplastics, thermosets and elastomers. Thermoplastics are long-chain polymers which are linear but have some degree of chemical bonding to adjacent chains. Alkyds are a class of branch-chain polyesters and form an insoluble thermosetting polymer film, formed by condensation polymerization. The reaction of compounds to form long-chain molecules with water as the usual by-product. Plasticizers work by depressing the glass-transition temperature of polymers, weakening the bonds between individual polymer chains, making them softer at ambient temperatures and causing a greater tendency to flow with a higher permeability.
