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Polymer stabilizers (British English: polymer stabilisers) are chemical additives which may be added to polymeric materials to inhibit or retard their degradation. Mainly they protect plastic and rubber products against heat, oxidation, and UV light.
Hindered amine light stabilizers (HALS) are chemical compounds containing an amine functional group that are used as stabilizers in plastics and polymers. [1] These compounds are typically derivatives of tetramethylpiperidine and are primarily used to protect the polymers from the effects of photo-oxidation; as opposed to other forms of polymer degradation such as ozonolysis.
Antiozonants prevents or retards the degradation of polymers caused by ozone (ozone cracking) sequestrants, forming chelate complexes and inactivating traces of metal ions that would otherwise act as catalysts; ultraviolet stabilizers are used to protect polymers from effects of ultraviolet radiation and come to 2 main types.
Polymerization in which polymer is formed in monomer, or monomer-solvent droplets in a continuous phase that is a nonsolvent for both the monomer and the formed polymer. Note 1: In suspension polymerization, the initiator is located mainly in the monomer phase. Note 2: Monomer or monomer-solvent droplets in suspension polymerization have
The onset of thermal degradation dictates the maximum temperature at which a polymer can be used. It is an important limitation in how the polymer is manufactured and processed. For instance, polymers become less viscous at higher temperatures which makes injection moulding easier and faster, but thermal degradation places a ceiling temperature ...
The way that the dry soils get a lot lighter between Table I on page 99 and table IV on pages 102-3 is eventually explained by the fact that Table I has pycnometer densities. For those who may already see reasons to learn more about the thermal conductivities of the soils it is free from the Army Cold Regions Research and Engineering Laboratory.
A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, [ 1 ] such as glass-reinforced plastic radar domes on aircraft and graphite - epoxy payload bay doors on the ...
Polymers represent another large area in which thermal analysis finds strong applications. Thermoplastic polymers are commonly found in everyday packaging and household items, but for the analysis of the raw materials, effects of the many additive used (including stabilisers and colours) and fine-tuning of the moulding or extrusion processing used can be achieved by using differential scanning ...