反应详情

A mixture containing 450 ml of degassed oxygen-free water, 60 ml of freshly distilled acrolein, 9 ml of acrylic acid, 6.6 ml of a solution of water oxygenated to 30 % and 12 ml of 2 N sulphuric acid, is prepared in a nitrogen atmosphere. 150 ml of a 2.75 % solution of sodium nitrite in degassed water is then progressively added over a period of about 40 minutes. On completion of the reaction, the pH-value is between 3 and 4 and the copolymer is present in precipitated form. After filtration, the precipitate is washed first with a solution of 0.002 M hydrochloric acid and then with acetone and dried. 7.75 g of the required copolymer are thus obtained. The presence of free aldehyde groups is detected by measuring the reducing power by the method J. S. Thompson et al already referred to in the text. In addition, the presence of free acid groups is detected by titration. It is found that 14 % by weight of the copolymer is in the form of free aldehyde groups and 17.6 % in the form of free acid groups.

1. customoxygenated to 30 % and 12 ml of 2 N sulphuric acid
2. customis prepared in a nitrogen atmosphere
3. customOn completion of the reaction
4. filtrationAfter filtration
5. washthe precipitate is washed first with a solution of 0.002 M hydrochloric acid
6. dry with materialwith acetone and dried