Substance to stop and make watertight against leakage.
Substance which markedly speeds up the cure of an adhesive when added in minor
quantity as compared to the amounts of the primary reactants and without itself
Complex carbohydrate (C6H10O5)n formed of microfibrils of glucose molecules.
Chief constituent of the cell walls of plants, and consequently chief
constituent of many fibrous plant products such as paper and board, and cotton,
linen and rayon cloth.
Paste-like sealant. Depending
on its composition, may be either rigid or elastic once it has set, and may
have adhesive properties in addition to its sealant properties.
Glue which is solvent based, giving water-resistant bond and with the benefit
that surplus glue can be removed, using an appropriate cleaner. Toxic and
Chloroprene Rubber, CR
Syn. Chlorobutadiene, Neoprene, Polychloroprene.
Compounding ingredient used in small amounts to increase the crosslinking
efficiency of certain non-sulfur vulcanizing systems or to modify the
properties given by such systems.
Note: The term is usually identified with additives used to modify
by organic peroxides.
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
Failure within the adhesive under a stress. Occurs when internal strength of
the adhesive is not as great as the forces applied to it. Adhesive remains
bonded to both sustrates. (more
about failure mechanisms)
Adhesive that sets at room temperature (20?).
Suspension and dispersion of submicron particles in a liquid medium without
their dissolution in the medium.
Additive acting as a surfactant to stabilized emulsion or collo?al media.
Syn. Emulsifying agent,
Intimate admixture of a polymer with all the materials necessary for the
Adhesive material containing conductive particles (metallic powder, carbon
black, graphite) added to increase electrical conductivity. Used to replace
solder joints in electronics assemblies, obviating the need for defluxing with
a solvent and, secondarily, eliminating the use of lead in solder.
Solvent based adhesive but with added properties which produce an immediate
bond. One part adhesive needing no mixing. Adhesive is applied to both
surfaces, let dry, and then pressed together to create an instant bond. Makes
good bonds in most materials but is not structural in strength.
Contact adhesion time: Period of time when using a contact adhesive during
which the dry adhesive layers may still be bonded together.
Syn. Open time
Pressure applied to the assembly to achieve a bond in contact adhesives.
Additive for protecting lubricated metal surfaces against chemical attack by
water or other contaminants.
Substance, which promotes or establishes a stronger bond at the resin
matrix/reinforcement interface. (see
Severe breakdown of internal cohesive forces of a sealant either during cure or
afterward, as a result of excessive stress. Two typical examples are side and
center cracking in an expansion joint. Shrinkage upon curing of elongation can
build up excessive stress either at the center of the joint or near the center
of the joint causing severe failure.
Similar to cracking. However, it is much less severe and does not destroy the
basic function of the caulk.
Crazing only extends a few molecules deep into the surface of the product (due
again to excessive stress) and can occur during the curing phase or after being
exposed to high elongation and
Effect of strain and/or time on the shape of polymer layers. Even under little
stress the adhesive layer changes shape.
Formation of chemical bonds between polymer chains leading to the formation of
a three dimensional network. Final materials are called thermosets.
Catalytic or reactive agent which when added to resin causes crossliking of
Syn. Curing agent
Changement of the properties of a resin
by chemical reaction, which, for example, may be condensation, polymerization,
vulcanization or addition; usually accompanied by the action of either
heat or catalyst or both, and with or without pressure. Fully cured materials
exhibit maximum physical, thermal and chemical properties in use.
Time required to complete the cure process.
Chemical which reacts with an adhesive polymer to cause solidification.
Approximately equal amounts of adhesive resin and curing agent are mixed
together to form a solid adhesive. Usually Part A of a two-part adhesive.
Special type of acrylic. Cures through reaction with moisture held on the
surfaces to be bonded. Needs close-fitting joints. Usually solidifies in
seconds and suits to small plastics parts, metals and to rubber. Setting times
range from 5 to 130 seconds.