反应详情

The same vessel as in Example 1 was charged with 130 g. of methanol, 25 g. of water, 320 g. of vinyl acetate, 15 g. of 30% aqueous solution of sodium ethylenesulfonate and 2.8 g. of azobisisobutylonitrile, and polymerization was carried out at a temperature of 70°C. for 3 hours. After adding 2.8 g. of 30% aqueous solution of sodiem ethylenesulfonate to the vessel, the polymerization was further continued for 5 hours to give vinyl acetate-sodium ethylenesulfonate copolymer containing 2.3% by mole of sodium ethylenesulfonate unit. Then the copolymer was hydrolyzed by a conventional method to give a modified PVA of which degree of hydrolysis was 92% by mole.

1. additionThe same vessel as in Example 1 was charged with 130 g
2. additionAfter adding 2.8 g