Поли(виниловый спирт) химические свойства, назначение, производство
Использование
NaA zeolite particles have been dispersed in a poly(vinyl alcohol) matrix to prepare a mixed-matrix membrane to study the pervaporative separation of water-butanol mixtures. Poly (vinyl alcohol)/gelatin based biocompatible polymeric scaffolds have been used to design for 3D cancer models.
Методы производства
Polyvinyl alcohol is produced through the hydrolysis of polyvinyl
acetate. The repeating unit of vinyl alcohol is not used as the starting
material because it cannot be obtained in the quantities and purity
required for polymerization purposes. The hydrolysis proceeds
rapidly in methanol, ethanol, or a mixture of alcohol and methyl
acetate, using alkalis or mineral acids as catalysts.
Определение
ChEBI: Polyvinyl alcohol is a homopolymer macromolecule obtained by polymerisation of vinyl alcohol. It is used as a pharmaceutic aid and ophthalmic lubricant as well as in the manufacture of surface coatings artificial sponges, cosmetics, and other products.
Общее описание
Polyvinyl alcohol (PVOH) is a hydrophilic linear polymer which forms copolymers of vinyl alcohol and vinyl acetate. Hence, the structural properties of polyvinyl alcohol polymers depend on the extent of polymerization and hydrolysis. Such changes cause both chemical and physical modifications such as esterification, etherification, crystallization, ion-polymer complexation in the polymer. Modified- PVOH structures are useful in biomedical applications.
Фармацевтические приложения
Polyvinyl alcohol is used primarily in topical pharmaceutical and
ophthalmic formulations. It is used as a stabilizing
agent for emulsions (0.25–3.0% w/v). Polyvinyl alcohol is also used
as a viscosity-increasing agent for viscous formulations such as
ophthalmic products. It is used in artificial tears and contact lens
solutions for lubrication purposes, in sustained-release formulations
for oral administration, and in transdermal patches. Polyvinyl
alcohol may be made into microspheres when mixed with a
glutaraldehyde solution.
Промышленное использование
Polyvinyl alcohol is a tough, whitish polymerthat can be formed into strong films, tubes, andfibers that are highly resistant to hydrocarbonsolvents. Although polyvinyl alcohol is one ofthe few water-soluble polymers, it can be renderedinsoluble in water by drawing or by theuse of cross-linking agents.
Профиль безопасности
Questionable
carcinogen with experimental carcinogenic
and tumorigenic data by implant route.
Flammable when exposed to heat or flame;
can react with oxidizing materials. Slight
explosion hazard in the form of dust when
exposed to flame. To fight fire, use alcohol
foam, CO2, dry chemical. When heated to
decomposition it emits acrid smoke and
irritating fumes.
Безопасность
Polyvinyl alcohol is generally considered a nontoxic material. It is
nonirritant to the skin and eyes at concentrations up to 10%;
concentrations up to 7% are used in cosmetics.
Studies in rats have shown that polyvinyl alcohol 5% w/v
aqueous solution injected subcutaneously can cause anemia and
infiltrate various organs and tissues.
(mouse, oral): 14.7 g/kg
(rat, oral): >20 g/kg
хранилище
Polyvinyl alcohol is stable when stored in a tightly sealed container
in a cool, dry place. Aqueous solutions are stable in corrosionresistant
sealed containers. Preservatives may be added to the
solution if extended storage is required. Polyvinyl alcohol undergoes
slow degradation at 100°C and rapid degradation at 200°C; it
is stable on exposure to light.
Несовместимости
Polyvinyl alcohol undergoes reactions typical of a compound with
secondary hydroxy groups, such as esterification. It decomposes in
strong acids, and softens or dissolves in weak acids and alkalis. It is
incompatible at high concentration with inorganic salts, especially
sulfates and phosphates; precipitation of polyvinyl alcohol 5% w/v
can be caused by phosphates. Gelling of polyvinyl alcohol solution
may occur if borax is present.
Регуляторный статус
Included in the FDA Inactive Ingredients Database (ophthalmic
preparations and oral tablets). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable
Non-medicinal Ingredients.
Поли(виниловый спирт) препаратная продукция и сырье
сырьё
препарат