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The aminoxyl radical (N-O•) combines with free radicals in polymers: N-O• + R• → N-O-R Although they are traditionally considered as light stabilizers, they can also stabilize thermal degradation. Even though HALS are extremely effective in polyolefins, polyethylene and polyurethane, they are ineffective in polyvinyl chloride (PVC). It ...
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.
Supports a range of annotation types. Annotations are stored separately from the unmodified PDF file, or (since version 0.15 with Poppler 0.20) can be saved in the document as standard PDF annotations. Evince: GNU GPL: Yes Yes Default PDF and file viewer for GNOME; replaces GPdf. Supports addition and removal (since v3.14), of basic text note ...
Skim is an open-source PDF reader. It is notably the first free software PDF reader for macOS. [2] It is written in Objective-C, and uses Cocoa APIs. It is released under a BSD license. It is also cited as being able to help annotate and read scientific papers. [3]
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
In polymer chemistry, polymerisation inhibitors (US: polymerization inhibitors) are chemical compounds added to monomers to prevent their self-polymerisation. Unsaturated monomers such as acrylates, vinyl chloride, butadiene and styrene require inhibitors for both processing and safe transport and storage.
In industrial chemistry, a stabilizer or stabiliser is a chemical that is used to prevent degradation. [1] Above all, heat and light stabilizers are added to plastic and rubber materials because they ensure safe processing and protect products against aging and weathering.
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 ...