Definitions /Dictionary/Glossary - nptel

Addition Polymerization: Chemical reaction in which simple molecules (monomers) are added
to each other to form long-chain molecules (polymers) without byproducts.
Additive: A material used to modify the properties of polymer resins. Examples include
plasticizers, initiators, light stabilizers and flame-retardants.
Adhesion: The state in which two surfaces are held together by an interlocking action or force.
Adhesive: A film, liquid or paste capable of holding the surfaces of two materials together.
Admixture: Addition and homogeneous dispersion of discrete components, before cure.
Aggregate: Hard, coarse material usually of mineral origins used in composite tools. Also used
in flooring or as a surface medium.
Aging: The process of exposing materials to an environment for an interval of time.
Air-Bubble: A localized, non-interconnected, spherically shaped entrapment of air within and
between the plies of reinforcement.
Air Splice: The coupling made by a jet of air to entwine/snarl two roving doffs together. The air
splice is used instead of a knot.
Air Vent: It is a small outlet to prevent entrapment of gases in a molding or tooling fixture.
Alkyd Plastics: Resin composed principally of polymeric esters, in which the recurring ester
groups are an integral part of the main polymer chain or are part of the cross links present
between chains.
Alligatoring: Visible cosmetic defect in exposed gel coat resembling wrinkled or alligator-like
skin.
Alloy: In plastics, a blend of polymers or copolymers blended with other polymers or elastomers
under select conditions.
Ambient: Surrounding environmental conditions, such as pressure, temperature, or relative
humidity.
Amine Resins: A synthetic resin derived from the reaction of urea, thiourea, melamine or allied
compounds with aldehydes, particularly formaldehyde.
An Isotropic: Exhibiting different properties when tested along axes in different directions. See
An Isotropic laminate
An Isotropic Laminate: A laminate whose properties are different in different directions.
Angle-Ply Laminate: A laminate with fibers of adjacent plies oriented at alternating angles.