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Light stabilizer are used to inhibit polymer photo-oxidation, which is the combined result of the action of light and oxygen. Like autoxidation this is a free radical process, hence the antioxidants described above are effective inhibiting agents, however additional classes of additives are also beneficial, such as UV absorbers, quenchers of ...
ultraviolet stabilizers are used to protect polymers from effects of ultraviolet radiation and come to 2 main types. UV absorbers which essentially act the same way as sunscreens Quenchers, which dissipate the radiation energy as heat instead of letting it break chemical bonds; often organic nickel salts, e.g. nickel phenolates
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.
Lignosulfonates (LS) are water-soluble anionic polyelectrolyte polymers: they are byproducts from the production of wood pulp using sulfite pulping. [1] Most delignification in sulfite pulping involves acidic cleavage of ether bonds, which connect many of the constituents of lignin. [2]
In polymer science, dispersion polymerization is a heterogeneous polymerization process carried out in the presence of a polymeric stabilizer in the reaction medium. . Dispersion polymerization is a type of precipitation polymerization, meaning the solvent selected as the reaction medium is a good solvent for the monomer and the initiator, but is a non-solvent for the po
A polymeric foam is a special foam, in liquid or solidified form, formed from polymers. [1] Examples include: Ethylene-vinyl acetate (EVA) foam, the copolymers of ethylene and vinyl acetate; also referred to as polyethylene-vinyl acetate (PEVA) Low-density polyethylene (LDPE) foam, first grade of polyethylene (PE)
Dyes and pigments are used in polymer materials to provide colour, however they can also effect the rate of photo-oxidation. Many absorb UV rays and in so doing protect the polymer, however absorption can cause the dyes to enter an excited state where they may attack the polymer or transfer energy to O 2 to form damaging singlet oxygen.
Polymers become charged through the dissociation of the monomer side groups. If more monomer side groups are dissociated, the polymer has a higher charge. In turn, the charge of the polymer classifies the polyelectrolyte, which can be positive (cationic) or negative (anionic).