control 11 1 5 1 sodium acetate trihydrate 7 05 620 12 0 5 1 sodium acetate trihydrate 6 32 737 13 0 1 1 sodium acetate trihydrate 6 54 767 14 0 1 none 5 02 273 15 0 05 1 sulfuric acid 1 90 163 in a three necked reaction kettle of volume 2 liter 17 0 g of cellulose rayonier rayfloc j cuene i v 8 39 units was suspended in 365 ml of acetic acid after 10 minutes stirring at room temperature 8 5 g of phthalic anhydride and 1 7 g of sodium acetate trihydrate were added to the suspension the temperature of the suspension was gradually raised to 80 u00b0 c over a period of 1 hour and the reaction carried out at this temperature for either 2 hours example 16 4 hours example 17 or 8 hours example 18 the reaction mixture was filtered and the obtained carboxylated cellulose fibers from each reaction washed with distilled water 5 times and prepared into handsheets the handsheets were air dried below 50 u00b0 c before taking cuene i v and carboxyl content measurements the cellulose phthalate fibers obtained in this manner displayed the following characteristics sample.