Cellulose acetates from linters and sisal: correlation between synthesis conditions in DMAc/LiCl and product properties.
We report the acetylation of celluloses from sisal (untreated and alkali treated) and cotton linters (alkali treated), under homogeneous solution conditions, using DMAc/LiCl as solvent system. Our target was to evaluate the effects of cellulose dissolution and reactions conditions on the product properties. The products were characterized in terms of degree of substitution (DS) by 1H NMR, and molar weight distribution (MWD) by size exclusion chromatography. Changes in the DS of the products were correlated with reaction conditions and solution properties. It was found that the dissolution of celluloses and degree of substitution of cellulose derivatives depends on a fine adjustment of the dissolution/derivatization conditions, as well as on the origin (sisal or linters) of celluloses.
Ass
Beatriz A P
BA
Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, CEP 13560-970, São Carlos, SP, Brazil.
Ciacco
Gabriela T
GT
Frollini
Elisabete
E
D000081:Acetamides / Q000737:chemistry*; D000085:Acetates / Q000737:chemistry*; D000107:Acetylation; D027882:Agave / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D002850:Chromatography, Gel; D003368:Gossypium / Q000737:chemistry*; D018021:Lithium Chloride / Q000737:chemistry*; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014783:Viscosity; D014961:X-Ray Diffraction
D000081:Acetamides; D000085:Acetates; D012996:Solutions; D012997:Solvents; D002482:Cellulose; D018021:Lithium Chloride