OXIDATION AND CHARACTERIZATION OF STARCH WITH TEMPO/NaBr/NaClO
Cornstarch was oxidized with sodium hypochlorite using 2,2,6,6-tetramethyl-1-piperidine oxoammonium ion (TEMPO) and NaBr as the catalysts. Effects of the amount of NaClO, pH value of the reaction media, reaction temperature, and reaction time on the contents of carboxyl group and the yield of oxidized starch were investigated, and the optimum oxidation conditions were determined. The results showed that the amount of sodium hypochlorite made the greatest influence on the content of carboxyl group on cornstarch, and the yield of oxidized starch would decrease along with the increase of the amount of sodium hypochlorite or the prolonging of the reaction time. However, reaction temperature and pH value of reaction media made less influence on the yield of oxidized starch. The optimum oxidation conditions of cornstarch were as follows: the amounts of TEMPO, NaBr and sodium hypochlorite were 0.8％, 10％ and 35％ (based on the weight of cornstarch) respectively, pH value of reaction media 10.5, reaction temperature 0oC, and reaction time 2 h. The content of carboxyl group of the oxidized starch obtained on the aforesaid conditions reached 5.3％, and the yield of oxidized starch was 88.8％. Furthermore, SEM, viscosity and transmittance are used to characterize the properties of oxidized cornstarch. Compared with raw starch, the paste viscosity of the oxidized starch decreased more than 90％, and transmittance of paste liquid increased from 48％ to 94％.
cornstarch NaClO oxidation TEMPO carboxylic group yield
Cao Jingjing Yang Yiqin
College of Light Industry of Science and Engineering,Nanjing Forestry University, Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology,Nanjing, 210037, China
国际会议
广州
英文
228-231
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）