Glossary

Pounds per square inch; a unit of measure of pressure.

The maximum internal temperature reached by a reacting composition.

A measure of bond strength. The torque required in order to separate an adhesive and an adherend, as done in the climbing drum peel test (ASTM D-1781).

The measure of the strength of an adhesive bond. It is the average load per unit width of bond line required to part bonded materials where the angle of separation is 180 degrees and the separation rate is 6 in/min. (ASTM D-903).

The loosening of a coating or layer from a base material.

A test for surface hardness using a numbered set of increasing hardness lead pencils. Surface hardness is designated by the first numbered pencil that will scratch the surface, starting with the softest pencil.

The entering of one material into another material, measured by the depth of penetration.

A simplified system of measuring acidity or alkalinity irrespective of the acid or alkali involved.

A fine, solid, typically inorganic particle used in the preparation of colored products. It is substantially insoluble in the vehicle versus a dye, which is soluble.

The concentration of pigments and extenders by volume in a liquid paint.

Small pore-like flaws in a dried film which appear like pin pricks.

The formation of small cavities in a metal substrate due to corrosion.

The tendency of a material to remain deformed after reduction of the deforming stress, to a value equal to or less than its yield strength.

An additive used to improve flexibility or to facilitate compounding.

A colloidal dispersion (suspension) of a resin in a plasticizer without a solvent.

The Bureau of Standards unit for measuring viscosity.

A resin composed of polymeric esters in which the recurring ester groups are an integral part of the main polymer chain. Unsaturated polyesters contain carbon double bonds that permit cross-linking and thus conversion of the resin to a substantially infusible and insoluble product.

A compound formed by the reaction of simple molecules having functional groups that permit their combination to proceed to high molecular weights under suitable conditions. Polymers may be formed by polymerization or polycondensation. When two or more monomers are involved, the product is called a copolymer.

A chemical reaction in which the molecules of a monomer are linked to form large molecules whose molecular weight is a multiple of that of the original substance. When two or more monomers are involved, the process is called copolymerization.

The reactive component in PU having OH groups.

The formation of small eruptions in dried film due to entrapment of low boiling solvents.

The additional operations to which a cured composition is subjected to enhance one or more properties.

The period of time during which a resin, after being mixed with the curing agent, can be used.

The covering of an item (such as coils in motors and generators) by a protective casting. Also called encapsulation.

A low polymeric intermediate between that of the monomer and the final polymer or resin.

See Accelerator.