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Depyrogenation refers to the removal of pyrogens from solutions, most commonly from injectable pharmaceuticals. A pyrogen is defined as any substance that can cause a fever. Bacterial pyrogens include endotoxins and exotoxins , although many pyrogens are endogenous to the host.
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 ...
Polybutylene succinate (PBS) (sometimes written polytetramethylene succinate) is a thermoplastic polymer resin of the polyester family. PBS is a biodegradable aliphatic polyester with properties that are comparable to polypropylene. It may also be referred to by the brand names GsPLA or BioPBS (Mitsubishi Chemical). [1]
Polyester resins are synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic anhydride is a commonly used raw material with diacid functionality in unsaturated polyester resins. [1] Unsaturated polyester resins are used in sheet moulding compound, bulk moulding compound and the toner of laser printers.
Ceiling temperature is a measure of the tendency of a polymer to revert to its constituent monomers. When a polymer is at its ceiling temperature, the rate of polymerization and depolymerization of the polymer are equal. Generally, the ceiling temperature of a given polymer is correlated to the steric hindrance of the polymer’s monomers.
A polyester shirt Close-up of a polyester shirt SEM picture of a bend in a high-surface area polyester fiber with a seven-lobed cross section A drop of water on a water resistant polyester Polyesters can contain one ester linkage per repeat unit of the polymer, as in polyhydroxyalkanoates like polylactic acid , or they may have two ester ...
Polyester has high glass transition temperature T g and high melting point T m, good mechanical properties to about 175 °C, good resistance to solvent and chemicals. It can exist as fibers and films. The former is used in garments, felts, tire cords, etc.
Deweighting is an alkaline hydrolysis treatment that affects the surface fibers of the polyester and reduces the decitex or denier of fibers, weight loss of between 10% and 30% is possible during the treatment. [2] Polyester and cotton blends can be treated with an alkali process to make them look and feel like silk. [3]