IMPROVING MOISTURE ABSORPTION,RETENTION ANDA NTI-OXIDANT ABILITY OF NATURAL POLYSACCHARIDE POLYMER IN A BIOLOGICAL APPROACH
Chitosan,a natural polysaccharide polymer,whose output is the second largest in nature just behind cellulose,is often used as a chemical additive or biomass resource in the field of papermaking process and biorefinery-based functional materials.The experiments first step is to obtain low molecular weight chitooligomer in 4000-5000 Daltons,which is mainly the polysaccharide polymer degraded by hydrogen peroxide.Then laccase-TEMPO system wasused to selectively oxidize primary hydroxyl of chitooligomerC-6 position to carboxyl groups.The dosage of TEMPO,an efficient oxidizing agent,were1%,2%,4%,8%(related to chitooligomer)in different samples respectively,so as to prepare polysaccharide products in varying degrees of oxidation.Then,carboxyl group content,moisture absorption,moisture retention and anti-oxidant ability were detected in order to explore the impact of carboxyl group content on the performance of oxidized chitooligomer.Results showed that increased usage of TEMPO can lead to a better oxidationeffect of chitooligomer.When the usage of TEMPO was 8%,the carboxyl groupcontentin the oxidation product reached up to 2.82%.Analysis of moisture absorption,moisture retention and anti-oxidant ability of oxidation products showed all of the three properties were evidently improvedwith use of TEMPO.The moisture absorption rate of oxidation product at saturated solution of(NH4)2SO4(RH=81%)reached its peak of 62.28%with the 2%usage of TEMPO,and ABTS·+radical scavenging ability was 85.38%at a consistency of 0.5 mg/ml with the 8%usage of TEMPO.Carboxyl group content in the oxidized products accountsfor this change.Therefore,moisture absorption,retention and anti-oxidant of oxidized products can be strengthened by adopting a green bio-oxidation method to oxidize the natural polysaccharide polymer and to increase the carboxyl group content in its molecule.The oxidized chitooligomer with the 2%dosage of TEMPO has a better moisture absorption,moisture retention and anti-oxidant ability,further being applied in the field of food,medicine,cosmetics and chemical.
Xin Bu Ji-cheng Pei Fang-dong Zhang Zheng-Hui Shen Zhi-min Zhou
Tianjin Key Lab of Pulp and Paper,Tianjin University of Science & Technology Tianjin,300457,China
国际会议
第五届制浆造纸新技术国际研讨会(ISETPP)暨第三届国际造纸与环境学术大会(IPEC)
广州
英文
1-6
2016-11-07（万方平台首次上网日期，不代表论文的发表时间）