ポリビニルアルコール 化学特性,用途語,生産方法
外観
白色〜わずかにうすい黄色, 粒状〜粉末
定義
本品は、ポリ酢酸ビニル(*)の加水分解物であり、次の化学式で表される。
参照表示名称：ポリ酢酸ビニル
溶解性
温水にやや溶けやすく、エタノール及びジエチルエーテルにほとんど溶けない。
解説
ポリ(ビニルアルコール)略称PVA．で表されるビニルアルコールの重合体で，ポバールともよばれる．ビニルアルコールは単量体としては実在しないので，実際にはポリ(酢酸ビニル)をアルカリ，酸，アンモニア水などでけん化することにより得られる高分子化合物である．主鎖はビニルアルコール単位の繰り返しで，1,3-グリコール形であるが，1～2％ 以内の1,2-グリコールを含んでいる．上述した方法で得られるポリ(ビニルアルコール)は，アタクチックポリマーであると考えられている．それにもかかわらず，このポリマーが高い結晶性を示すのは，-OH基の大きさが比較的小さく，-OH…O型の水素結合がさらにそれを補っているためと考えられている．ガラス転移温度約65～85 ℃．
用途
吸光分析用分散剤、乳化剤。
用途
ビニロン合成繊維、糊剤
化粧品の成分用途
結合剤、皮膜形成剤、親水性増粘剤
効能
増粘剤
主な用途／役割
ポリ酢酸ビニルを酸、アルカリなどでケン化して得られる。紙用接着剤、切手等の糊用原料、水性高分子イソシアネート系接着剤原料として使用される。
物理的特性
引張強さ，圧縮強さ，耐衝撃性，耐摩擦性にすぐれている．水には徐々に溶解するが，分子量が大きくなると溶解性は低下する．一般の有機溶媒には不溶であるが，酢酸，グリセリン，アセトアミド，フェノールには加熱すると溶解し，液体アンモニアに溶ける．ポリ(ビニルアルコール)のヒドロキシ基は，低分子多価の第二級アルコールと同じく，アセタール化，アセチル化，脱水など種々の反応をする．ポリ(ビニルアルコール)からつくられた繊維は，ビニロンの名称で市販されている．そのほか，のり剤，塗料，接着剤，乳化剤，洗剤，農薬のユニット包装用など広い用途をもつ．
使用
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.
調製方法
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.
定義
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.
一般的な説明
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.
応用例（製薬）
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.
工業用途
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.
安全性プロファイル
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.
安全性
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
貯蔵
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.
不和合性
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.
規制状況(Regulatory Status)
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.
ポリビニルアルコール 上流と下流の製品情報
原材料
準備製品