CELL 174 |
| A series of novel regenerated cellulose (RC) films were prepared successfully from cellulose in 7wt% NaOH / 12wt% urea aqueous solution pre-cooled to -12oC, which was a cheap and non-polluting method. There was no evaporation of the chemical agents during dissolution of cellulose at low temperature, and the byproducts could be easily separated and recycled to utilize. The results from CP/MAS 13C NMR spectra and X-ray diffraction strongly confirmed that the cellulose dope did transform into regenerated cellulose II during the coagulation with 5 wt% H2SO4. The resultant RC films possessed the homogenous structure, excellent optical transmittance (90% at 800 nm), good tensile strength and biodegradability. The drawing process could improve significantly on their mechanical properties to reach to 106 MPa. The biodegradation test revealed that the RC films could be biodegraded completely, and the degradation half-lives in soil at about 30oC was given to be 11 days. This new pathway offers great potential for producing biodegradable films by using a simple and “green” process. The transparent and safe RC films provided a wide application in the fields of the packaging and functional materials. |
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Cellulose-Based and Other Green Composites
12:55 PM-3:45 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 232, Oral
Division of Cellulose & Renewable Materials |