Kuraray Co., Ltd.

Universitéde Liége

Antoine Debuigne

Kazuhiko Maekawa

Christophe Detrembleur

Takumi Takayama

Christine Jerome

Yusuke Amano

Christine Jérôme

A polyvinyl alcohol has a number-average molecular weight (Mn) from 4,400 to 440,000, a molecular weight distribution (Mw/Mn) from 1.05 to 1.70, a degree of saponification from 80 to 99.99 mol %, wherein the polyvinyl alcohol contains an end group represented by a formula (I) below, and a molar ratio (X) of the end group based on total monomer units and the number-average molecular weight (Mn) satisfy a formula (1) below. Such a polyvinyl alcohol has a narrow molecular weight distribution and a high number-average molecular weight with hue good. (In the formula, Rdenotes an optionally substituted aromatic group having a carbon number from 6 to 20, and Rdenotes a hydrogen atom, an alkyl group having a carbon number from 1 to 20, or an optionally substituted aromatic group having a carbon number from 6 to 20.)X&#xb7;Mn/44&#x2265;0.5&#x2003;&#x2003;(1)

Polyvinyl alcohol and method for producing polyvinyl alcohol

A polyvinyl alcohol is produced in a method comprising: a polymerization step comprising polymerizing vinyl ester monomers by controlled radical polymerization in the presence of a radical initiator and an organic cobalt complex to obtain a polymer solution containing a polyvinyl ester; an extraction step comprising extracting a cobalt complex from the polymer solution by contacting an aqueous solution containing a water-soluble ligand with the polymer solution; and a saponification step comprising saponifying the polyvinyl ester after the extraction step to obtain a polyvinyl alcohol. A method for producing a polyvinyl alcohol is thus provided that has a narrow molecular weight distribution and a high number-average molecular weight with good hue and further good solubility in water.

Polyvinyl alcohol and method for producing same

Growing community of inventors

Liege, Belgium

Antoine Debuigne