Help Glossary

The Danish name is shown in italics after the English name. Use the browser's search function to locate desired terms.

A Additive (additiv)
Chemical agent added to polymers for protective or other reasons. Examples are plasticizers, colour, UV-protectors, fire-protectors, etc.

Amorphous structure (amorf struktur)
Structure that has no order in its molecules. (See also crystalline structure).

Anisotropy (anisotrop)
The tendency of a material to exhibit different properties in response to stresses applied along axes in different directions.
B Biocompatibility (biokompatibilitet)
Capability of a substance or material to be compatible with life (e.g no toxic or poisonous).

Biodegadration (bionedbrydning)
Biodegradation may be defined as the biologically mediated degradation of a material to generate CO2, water and biomass, and leaving no toxic residues.

Brittleness (skørhed)
Property of a material to break in two pieces with little or no gross plastic deformation preceding the separation of the material. Fragility.

C Compounding (compoundering)
Mixing of polymers with additives. Se also additives.

Covalent bond (kovalent binding)
Characterized by electrons shared among two adjacent atoms. This "sharing" prevents the electrons from moving (insulation).
Strong directionality - number of neighbours limited; high strength (slightly less than ionic, 125-300 kcal/mol). (See also ionic bond and metallic bond).

Crystalline structure (krystallinsk struktur)
Structure in which the atoms are arranged in various orderly configurations, called lattices.
The basic repetitive unit of the structure is the unit cell. Cubic unit cells come in three flavours - simple cubic (SC), body-centered cubic (BCC) and face-centered cubic (FCC). Few materials have the hexagonal close packed (HCP) structure. (See also amorphous structure).
D Dielectric (dielektrikum)
An insulating medium or substance.

Danish Kroner is the currency used in Denmark. The amount of 7 DKK is approximately equal to 1 US dollar (Sept. 1997).

Dope (dope)
In electronics, doping a material (usually a semiconductor) means adding an impurity to produce a desired electrical characteristic.

Ductility (strækkelighed)
The extent of plastic deformation that a material undergoes before fracture.
A ductile material is pliable, not brittle, and can be drawn into wire.
E Elasticity (elasticitet)
Property of a material to deform under stress, but return to its original shape when the stress is removed. (See also plasticity).

Electric field (elektrisk felt)
A region of electrical influence.

Electrostriction (-)
The mechanical strain shown by some materials when placed in an electric field.

E-modulus (E-modul)
Modulus of elasticity, measure of rigidity. Is estimated as the relation between a material stress and the according strain. The E-modulus for plastic materials lies between 100 N/mm2 (flexible) and 10,000 N/mm2 (rigid).

Environmental notes (Miljønoter)
For materials, processes and products the environmental notes are intended to supply the reader with the very basic environmental information in relation to toxicity and occupational health hazards. To support a very simple LCA (life cycle assessment) the energy consumption is indicated as the equivalent oil consumption (1 kg of oil equals 45 MJ of energy). NOTE: Energy figures should not be compared between materials, but used for estimating total energy consumption for a product from cradle to grave!
F Fission (spaltning, atomspaltning)
Splitting or dividing a thing into more things, e.g. uranium in a nuclear explosion.

Fusion (fusion)
Uniting two or more things into one, e.g. two hydrogen atoms into one helium atom.
H Hardness (hårdhed)
Resistance to permanent indentation.
I Ionic bond (ion binding)
Atomic arrangment where an electrostatic attraction exists between oppositely charged ions.
Strongest bond (150-370 kcal/mol); no free electrons (insulation); no directionality - each ion is surrounded by maximum number of opposite signs. See also covalent bond and metallic bond.

Inorganic materials (uorganiske materialer)
Not organic, usually of mineral origin. (See organic materials).

Isotropy (isotropi)
Property of a material which shows the same physical properties in all directions. (See also anisiotropy)
M Malleability (smedelighed)
Property of a material to be hammered or pressed permanently out of shape without breaking or cracking. (See also ductility)

Matrix (matrix)
The basic substance in a composite material where the reinforcement is imbedded. The matrix is either plastic, metal, ceramic, or glass. (See also reinforcement)

Metallic bond (metallisk binding)
Atomic arrangement where one electron is shared by many positive ions. Sometimes referred to as "free electron gas".
No directionality - desire for the largest number of nearest neighbours; high strength (slightly less than covalent or ionic, 25-200 kcal/mol). See also covalent bond and ionic bond.

Monomer (monomer)
The smallest repetitive unit in a dimer, trimer, polymer.

O Organic materials (organiske materialer)
Materials containing carbon and often combined with hydrogen. (In contrast to inorganic, see also this).

Orientation (orientering)
Directional position of plastics chain molecules.
P Peltier effect (Peltier effekt)
Effect shown when an electric current passes through a circuit consisting of two junctions of two different types of conductors: one junction becomes cooler and the other warmer.

Plasticity (plasticitet)
Property of a material to deform under stress and not to return to the original shape when the stress is removed. (See also elasticity).

Plasticizer (blødgører)
Liquid additive to be compounded with rigid polymers for reducing their E-modulus, i.e. making them less rigid.

Polymer (polymer)
Chain-like molecules produced by polymerization of monomers. Also depicts materials built up from polymer molecules. (See also monomer).

R Refractoriness (ildfasthed, tungtsmeltelighed)
Property of a substance which is especially resistant to heat and corrosion.

Reinforcement (forstærkning)
A substance added to the matrix in composite materials in order to improve strength; ranges from short fibres through complex textile forms. (See also matrix)
S Stiffness (stivhed)
The relationship of load to deformation for a particular material.

Strain (tøjning)
The elastic deformation of a material as a result of stress.

Strength (styrke)
The strength of a material is the force needed to deform it.

Stress (spænding)
The internal force that resists change in size or shape, expressed in force per unit area (N/mm2).
T Toughness
The amount of energy per unit volume that a material dissipates prior to fracture.
V Van der Waals bond (Van der Waals binding)
Characterized by secondary bonding originating from electrical dipoles. Polarization produces slight electrostatic charge between molecules. (See also covalent, ionic and metallic bond).
Not directional; weak bond (1/100 of strong bonds, < 10 kcal/mol); hydrogen bond is an example.
Copyright © 1996-2008 Torben Lenau
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