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Study on the Influence of Pretreatment and Chain Length of Substituents on Cellulose Mixed Esters
김해리,남병욱 한국고분자학회 2014 Macromolecular Research Vol.22 No.7
In this work, homogeneous esterification of the cellulose mixed esters was accomplished with water-activatedα-cellulose, various saturated fatty acids, and acetic anhydride in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) medium to study the influence of activation and fatty acyl chain length on the cellulose mixed esters (CME). α-Cellulose was activated for 2 h at 50 oC in deionized water prior to esterification. CME was obtained after esterificationfor 5 h at 120 oC. The purified products were characterized in various ways. The morphology, structure, totaldegree of substitution, crystallization characteristics, thermal properties, contact angle, and film properties of CME wereexamined by FE-SEM, 1H NMR, FTIR, XRD, DMA, TGA, and CAA. These analyses revealed that the water activationpretreatment of α-cellulose was the critical factor affecting the esterification efficiency which is related to theoverall properties of the cellulose esters. It is also confirmed that the glass transition behavior of the cellulose esterschanges depending on the chain length of the substituents.
Raj K. Singh,Piyush Gupta,Om P. Sharma,Siddharth S. Ray 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-
Cellulose fatty esters with different fatty acids as lauric, myristic, palmitic, stearic and oleic acid having same degrees of substitution (DS 2.0) were prepared homogeneously using 1-butyl-3-methylimida- zolium chloride ([C4mim]+Cl). All samples were characterized by IR and NMR. The triboevaluation in terms of average friction coefficient was done by nanotribometer using 3000 ppm solution of each ester in polyol (pentaerythritol tetraoleate) which is taken as biolube reference fluid. The cellulose esters are found to show antifriction character in the order as myristate > palmitate > laurate > stearate > oleate.