Aqueous solution of stereoregular polyvinyl alcohol; method of making same; foams, fibers, and films obtained therefrom

Claim 1

A COMPOSITION-OF-MATTER CONSISTING ESSENTIALLY OF A SOLUTION OF WATER CONTAINING ABOUT 2 PERCENT TO ABOUT 20 PERCENT, BY WEIGHT, OF STEREOREGULAR POLYVINYL ALCOHOL WHICH IS INSOLUBLE IN WATER AT 100*C.; SAID SOLUTION BEING MAINTAINED AT A PRESSURE OF ABOUT 15 P.S.I.; SAID STEREOREGULAR POLYVINYL ALCOHOL HAVING BEEN PREPARED BY THE STEPS OF (1) COMBINING ABOUT 0.01 PERCENT TO ABOUT 1 PERCENT-BY WEIGHT OF A PEROXIDE CATALYST AND A MONOMER SELECTED FROM THE GROUP CONSISTING OF VINYL CHLOROACETATES AND VINYL FLUROACETATES, (2) POLYMERIZING THE MONOMER AT A TEMPERATURE IN THE RANGE FROM ABOUT ROOM TEMPERATURE TO ABOUT 80*C., (3) HYDROLYZING THE RESULTANT MONOMER IN THE PRESENCE OF A SOLVENT WHICH IS INERT IN BASIC ANHYDROUS SOLUTIONS, THE SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF TETRAHYDROFURAN AND DIOXANE, CARRYING OUT THE HYDROLYSIS IN A REFLUXING ANHYDROUS ALKALIMETAL ALCOHOLATE AND (4) NEUTRALIZING THE RESULTANT POLYVINYL ALCOHOL.