title: Controlling molecular weight and degree of deacetylation of chitosan by response surface methodology.
abstract: Response surface methodology (RSM) was used for controlling molecular weight (MW) and degree of deacetylation (DOD) of chitosan in chemical processing. In a reduced model, MW of chitosan is y = 1736166.406 - 250.745X(1)X(2) - 265.452X(2)X(3), with R( 2) = 0.86, and DOD of chitosan is y = 30.6069 + 0.3396X(1) + 0.4948X(2) + 0.0094X(3)(2), with R( 2) = 0.89. MW of chitosan depends on the crossproduct of temperature and NaOH concentration and the crossproduct of NaOH concentration and time, and DOD depends linearly on temperature and NaOH concentration, and quadratically on time. Chitosan was widely depolymerized in a range from 1,100 kDa to 100 kDa and deacetylated from 67.3 to 95.7% by NaOH alkaline treatment. MW and DOD of chitosan were drastically decreased and increased, respectively, with increase of temperature, reaction time, and NaOH concentration. Furthermore, the rate of MW decrease and DOD increase of chitosan gradually decreased with prolonged reaction time.
authors.affiliation: Graduate School of Biotechnology, and Department of Statistics, Korea University, Seoul 136-701, Korea.
authors.forename: Kwon T
authors.initials: KT
authors.lastname: Hwang
authors.forename: Soon T
authors.initials: ST
authors.lastname: Jung
authors.forename: Gee D
authors.initials: GD
authors.lastname: Lee
authors.forename: Manjeet S
authors.initials: MS
authors.lastname: Chinnan
authors.forename: You S
authors.initials: YS
authors.lastname: Park
authors.forename: Hyun J
authors.initials: HJ
authors.lastname: Park
mesh_terms: D000107:Acetylation; D002621:Chemistry / Q000295:instrumentation; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry*; D048271:Chitosan; D008970:Molecular Weight; D012972:Sodium Hydroxide; D013696:Temperature
chemical_list: D002686:Chitin; D012972:Sodium Hydroxide; D048271:Chitosan