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A-stage
Early stage of polymerization of thermosetting resins in which the material is still soluble in certain liquids and is fusible.
See B-stage, C-stage

Absorption (Light) (extended definition)
Decrease in directional transmittance of incident radiation (such as light), resulting in a modification or conversion of the absorbed energy, into heat, for example. Light incident on a specimen may be partially reflected, partially transmitted, or partially absorbed.

Accelerator
Chemical additive that hastens cure or chemical reaction, but does not necessarily cause the chemical reaction.
Syn. Promoter

Acid scavenger
Additive having the ability to neutralize acidic species from a formulation. It is mainly used to prevent equipment corrosion and to improve the stability of the material.
Families of acid scavenger are : Metallic Stearates, Hydrotalcite, Hydrocalumite or Zinc Oxide.

Acrylic resin
Family of polymer that refers to large variety of products. They are all made by (co) polymerization of acrylic monomers, such as acrylates (Methyl, Ethyl, Butyl) or acrylic acid. Used in molding and extrusion compounds.

Acrylic-based Impact Modifier
Generally core-shell particules containing an acrylic core used for impact modification of rigid PVC or impact modification of engineering polymers.
For more information, Visit our Acrylic Impact Modifiers Center.

Acrylonitrile Butadiene Styrene resin, ABS
Acrylonitrile Butadiene Styrene (ABS) is a polyphasic material. It has good impact resistance, very good structural strength and has a shiny impervious surface. It possesses high rigidity and impact strength, excellent abrasion resistance, excellent electrical properties, moisture, and creep resistance. ABS is resistant to inorganic salts, alkalies and many acids. It is commonly vacuum formed, molded or extruded. (Working Temperature Range: -25°C to +60°C)

Addition (or Polyaddition)
Polymerization reaction in which no byproducts are formed.

Additive
Product introduced into a polymer or applied to its surface in order to modify or to enhance its performances. There are numerous families of additives that can be classified into 3 main categories : property extenders, processing aids and modifiers.
In plastic industry, additives are very useful. To get information on Additives, use Techdirect.

Adhesion promoter
Adhesion promoters act at the interface to increase the adhesion between two substrates through the reduction of the interfacial tension. When the adhesion promotor is used to increase adhesion between two incompatible polymers it is also called a Compatibilizer. When the adhesion promotor is used to increase adhesion between a polymer and a filler it is called a coupling agent. Compatibilizers or coupling agents can be reactive or non reactive.
Syn. Bonding agent.
For more information, Visit our Adhesion Promoters Center.

Adsorption
Build up of a molecule at a surface. Not to be confused with absorption. Adsorption generally occurs because different parts of a molecule have an affinity for the two different phases on either side of the interface.

Ageing
The changing of a material with time under defined environmental conditions, leading to improvement or deterioration of properties. Addition of Antioxidants, UV / Light stabilizers, and so on, allows an improvement of ageing properties.

Alkyd
Resin formed by the condensation of polyhydric alcohols with polybasic acids. May be regarded as complex polyester (thermoset).

Amide
Organic compound that contains a carbonyl group bound to nitrogen. -CON- (C double bonded to O)

Amino resin
Thermosetting resin manufactured from amino compound and formaldehyde.
See also Urea formaldehyde resin, Melamine formaldehyde resin

Antidegradant
Compounding material used to retard deterioration caused by oxidation, ozone, light and combinations.
Note: Antidegradant is a generic term for such additives as Antioxidants, Antiozonants and UV / Light stabilizers.

Anti-fibrillant masterbatch
Product that prevents slit-tapes from splitting in machine direction.

Antifoaming agent (foam suppressant)
See Defoamer

Antifogging / Antidrip agent
Additive (mostly surface-active compounds) which is added to films or sheets in order to eliminate fogging and/or dripping that is caused by excess humidity.
For more information, Visit our Antifog agents Center.

Antioxidant
Compounding material used to retard deterioration caused by oxidation. Usually based on molecules that will scavenge free radicals as they are formed.
Different types are available: sterically hindered phenols and phosphites as base for polyolefins, sulphur based heat stabilizers and C-radical scavengers for special applications.
For more information, Visit our Antioxidants Center.

Antiozonant
Additive used to protect a polymer against the effects of ozone-induced degradation and hence used mainly in diene rubbers. Works either by providing a physical barrier to ozone penetration by forming a thin surface film of an ozone-resisting wax or by chemically reacting with ozone or polymer ozonolysis products, as do aromatic diamines such as p-phenylene diamine derivatives.

Antislip agent
Additive used to eliminate the sliding of parallel film surfaces over each other or the sliding of film surfaces over substrates.

Antistatic agent
Additive mainly acting at the surface of a polymer and minimizing static electricity (charge build-up, dust collection) in plastic materials. With external antistatic agents, the plastic is coated by spraying or immersion. Internal antistatic agents are incorporated into the polymer matrix and then migrate to the surface. Conductive fillers can also be used to minimize static electricity.
Main families of antistatic agents are: Fatty acid esters, Ethoxylated amines, Quaternary ammonium compounds, Alkylsulfonates, Alkylphosphates.

Antitack / Antiblock agent
Additive used to lessen the adhesion of the surface of products made from the formulation of like or different surfaces. Acts by producing a slight roughening of the surface. Typically finely divided, solid minerals, but some are waxes. Antiblock agents are mainly used in film extrusion.
Families of antiblock agents : Natural silica, Synthetic silica, Talc, Calcium carbonate, EBS.