Uniroyal’s trade name for polyurethane based on toluene diisocyanate and polyether glycols.
Formed by reaction between isocyanate groups and urethane groups.
Ammonia derivatives where one or more hydrogen atoms in ammonia have been replaced by carbonaceous radicals. Amines are used, among other things, as chain extenders (hardeners) and catalysts in the production of polyurethanes.
Acyclic compounds in which the carbon atoms are attached to each other to open, straight or branched chains.
Isocyanates based on aliphatic compounds.
Homocyclic compounds with six carbon atoms in the ring, which are unsaturated. The aromatics may consist of several such rings. The simplest aromatic compound is benzene.
Isocyanates based on aromatic compounds. They are cheaper than aliphatic, but discolored with aging.
Chemical compounds that are sometimes added to prevent oxidation of, among other things, polyurethane.
ELONGATION AT BREAK
The elongation when the sample fails under load.
“Pt-life”, the time a blend of prepolymer and chain extender is castable.
Difunctional alcohol, which is used as a chain extender in the manufacture of polyurethanes.
Baxenden Chemicals brand name for a series of urethane prepolymers.
Extremely powerful poison. Can be formed by heating polyurethanes and isocyanates.
Contains two isocyanate groups (see isocyanate). O=C=N-R-N=C=O.
The highest tensile stress a material can withstand before it breaks.
ELASTOMERS OR ELASTS
Collective name for rubber and thermoelastics. According to ISO 1382 “polymeric material, which quickly returns to almost original dimensions and shape upon unloading after being subjected to severe deformation by the action of low mechanical stress.”
E-module, Young’s module provides the relationship between stress (σ) and elongation (ε). For practical use, steel follows Hooke’s law E = σ / ε. Polymeric materials follow Hooke’s law only at very low elongations.
The ability of the molecular chains to return to their original position when loading ceases.
ESTERGRUPPER (-COOR) –
Occurs in polyester urethanes. Provides good mechanical properties, but can impair the hydrolysis resistance.
ETHER GROUPS -O-
Provides good hydrolysis resistance in polyurethane systems, but especially soft polyurethanes have lower mechanical properties than the corresponding polyester urethanes.
It refers to the solidity of a material when the mold is removed.
Elastics, which are crosslinked or can be crosslinked, so that it is practically insoluble (but can swell) in boiling solvents, including benzene and methyl ethyl ketone.
Opposite to hydrophobic.
Comes from Greek hydro = water, lys = decompose. Some polyester urethanes are easily hydrolyzed by hot water or water vapor.
Carbodiimides, which are added to polyester urethanes to delay the hydrolytic degradation.
Reactive group -OH
Chain extender, used to harden prepolymers to polyurethane. Multifunctional amines and glycols are used as hardeners.
The ability of the surface to withstand penetration. Measured for polyurethanes most often in Shore A or D. There is a certain connection between E-modulus and hardness.
Reactive groups – N=C=O, which reacts with hydroxyl groups (-OH) to urethanes and with amine groups (NH2) to urea (carbamide).
Used in the manufacture of cellular plastics. Leavening agents for polyurethanes are hydrogen fluorocarbon compounds, hydrogen fluorocarbons and carbon dioxide (formed by the reaction between isocyanate and water).
Substances that accelerate a chemical reaction without being consumed by oneself. For polyurethane production, amines and tin salts are used as catalysts.
The length of the polymer chains. The mechanical properties improve with increasing chain length.
Rubber materials are practically considered incompressible. At high pressures, however, the compressibility must be considered especially for polyurethanes and silicone rubber.
Dangerous to health. Formed during the combustion of polyurethanes and isocyanates.
Liquid Injection Molding.
Diphenylmethane diisocyanate. An aromatic diisocyanate for the production of solid and cellular polyurethanes. Not as volatile as TDI.
The ability of a material to withstand abrasion (wear). Distinguish between abrasion parallel to the surface and “abrasion” caused by incident goods at a large angle of incidence.
Comes from Greek poly=many and more=unit, i.e. large molecules.
Polymer containing urethane groups.
See service life
Reaction Injection Molding=reaction casting. Often used only for high pressure casting.
Reinforced Reaction Injection Molding. Reaction casting of reinforced polymers.
A material’s ability to withstand impact stresses
Frequently used release agent for polyurethane. Causes adhesion problems during gluing and painting.
UW-ELAST´s brand name for a series of polyether and polyester urethanes.
Read more about Slitan.
Denoted σ and is the force F divided by the area A. Often expressed in MPa.
Remaining deformation after loading.
Elast in which the cohesive forces necessary for the elastic deformation of the material are of a physical nature and thus can be eliminated by heating, whereby the material becomes plastically malleable at elevated temperature to return to its highly elastic state upon cooling.
Common aromatic diisocyanate for the production of solid and cellular polyurethanes. Due to the volatility and health risks, a polyurethane is often manufactured first.
Trekollan is partly a polyurethane material, but also a former company that is now part of UW-ELAST AB.
Read more about Trekollan.
Polymers return, with some time delay, to its original shape after loading. The viscoelastic part is mechanically reversible, but thermodynamically irreversible.
Bayer’s trade name for a polymer based on naphthalene diisocyanate and polyester glycols.
Read more about Vulkollan.
UREA GROUPS- -NHCONHR
Formed by reaction between isocyanates and amine groups NH2, Also called urea.
URETAN GROUPS- -NHCOOR
Formed by reaction between isocyanates – N=C=O and hydroxyl groups -OH.
Reactive viscous liquid, usually isocyanate terminated. Provides, among other things, lower health risks than monomeric isocyanates.
Uniroyal’s brand name for a series of castable polyurethanes.