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A-Stage. An early stage
in the reaction of certain thermosetting resins in which the material is fusible
and still soluble in certain liquids.
Adhesive. A substance capable of holding materials together by surface
attachment. Note- Adhesive is the general term and includes among other cement,
glue, mucilage and paste. All of these terms are loosely used interchangeably.
Aggregate. A hard fragmented material used with an epoxy binder as
a flooring
or surfacing medium. Also coarse filler used as a core for epoxy tools.
Aging. The change of a material with time under defined environmental
conditions, leading to improvement or deterioration of properties.
Amine. Curing agent for epoxy resins that is any of a class of ammonia
derivatives. They are derived from Ammonia (NH3).
B-Stage. An intermediate stage in the reaction of certain thermosetting
resins in which the material softens when heated and swells when in contact
with certain liquids, but may not entirely fuse or dissolve. The resin in
an uncured thermosetting system, is usually in this stage.
Bond. The union of materials by adhesives.
Bond Strength. The unit load applied in tension, compression, flexure,
peel, impact, cleavage, or shear, required to break an adhesive assembly with
failure occurring in or near the plane of the bond. Note-The term adherence
is frequently used in place of bond strength.
C-Stage. The final stage in the reaction of certain thermosetting resins
in which
the material is relatively insoluble and infusible. Certain thermosetting
resins in a
fully cured state are in this stage.
Catalyst. A substance which markedly speeds up the cure of an adhesive
when
added in minor quantity as compared to the amounts of the primary reactants.
Chalking. Formation of a dry powdery chalk-like appearance or deposit
on the
surface of a material. It is due to a breaking down of the material after
being
exposed to ultraviolet light, or other weathering.
Clarity. Degree of clearness in a cured epoxy system.
Cohesion .The state in which the particles of a single substance are
held together by primary or secondary valence forces observed in the tendency
of the substance to stick to itself. As used in the adhesive field, the state
in which the particles of the adhesive (or the adhered) are held together.
Compressive Strength. Crushing load at the failure of a specimen divided
by
the original sectional area of the specimen.
Cross-Link. Tying together large molecules and hence changing the physical
properties of material. Cross-linking usually involves formation of three
dimensional molecular network and is customarily associated with thermosetting
resins.
Cure. To change the physical properties of an epoxy by chemical reaction
through polymerization, usually accomplished in the presence of heat and catalyst,
alone or in combination.
Cure Cycle. The schedule of time periods at specified temperatures
to which a reacting thermosetting plastic or rubber composition is subjected
in order to reach certain specified properties.
Curing Agent. A catalytic or reactive agent which when added to resin
causes
polymerization.
