Polyvinyl alcohol and gel containing the same

A wound dressing material comprising a gel produced from a polyvinyl alcohol comprising (i) one or more structural units represented by the following formula (I):

• ##STR12## wherein R.sup.1 is hydrogen atom or a mono-valent hydrocarbon;
• and R.sup.2 and R.sup.3 are, independently, a mono-valent hydrocarbon group or R.sup.2 and R.sup.3 together form a ring along with the carbon atom to which R.sup.2 and R.sup.3 are bonded;
• or R.sup.1, R.sup.2 and R.sup.3 together form a ring along with the carbon atoms to which R.sup.1, R.sup.2 and R.sup.3 are bonded,
• wherein the structural units of formula (I) are present at a molar fraction of 0.05 to 0.50;
• and
• (ii) at least one structural unit represented by the following formula (II):
• ##STR13## wherein X is a group represented by the formula --CO--Y, -Y or --COCOOH, wherein Y represents a hydrocarbon group modified with at least one polar group selected from the group consisting of carboxyl, sulfo, amino and phosphonooxy groups;
• or a hydrocarbon group modified with a group having at least one polar group selected from the group consisting of carboxyl, sulfo, amino and phosphonooxy groups;
• or X forms a phosphonooxy group together with the oxygen atom to which X is bonded,
• wherein the structural units of formula (II) are present at a molar fraction of 0.0001 to 0.50.