NEW FUNCTIONAL MATERIALS FROM CELLULOSE
In the 21st century, the utilization of renewable resources to produce environment-friendly materials has become an international frontier which avoids using or producing harmful substances. The full potential of cellulose has not yet been exploited due to the lack of an environmental-friendly method. Faced with the serious pollution produced by the viscose method (use of CS2), we are realizing a dream of producing cellulose fibers, films and various functional materials via the new route by using low-cost reagents and a simple “green process that yields essentially non-toxic byproducts. For the first time, we have developed a novel solvent of cellulose, namely 7 wt ％ NaOH 12 wt ％ urea aqueous solution pre-cooled to -12 oC 1-3. Cellulose with weight-average molecular weight (Mw) smaller than 1.2×105 could be dissolved in the NaOH/urea aqueous system within 2 min on a typical laboratory scale and within 5 min even in a dissolution tank of 1000 L capacity (Jiangsu Long-Ma Green Fibers Co. Ltd.). It represents the most rapid dissolution of native cellulose. We demonstrated by using LLS, TEM, synchrotron XRD and 13C NMR that NaOH “hydrates could be more easily attracted to cellulose chains through the formation of new hydrogen-bonded networks at low temperatures, while the urea hydrates could be self-assembled at the surface of the NaOH hydrogen-bonded cellulose to form an inclusion complex (IC), leading to the good dissolution of cellulose. The self-assembled clusters created a possible new pathway for the “dissolution of natural polymers through the hydrogen-bonded arrangement of macromolecules and some special small molecules in an aqueous system. The cellulose solution remained a liquid state for a long time at 0 to 5 oC. 3 Therefore, we provided a non-toxic solvent system for the preparation of the cellulose solution, which can maintain clean air in the production environment, because no evaporation of any chemical agents during production. 11
cellulose functional material non-toxic solvent
Zhang Lina
Department of Chemistry, Wuhan University, Wuhan,430072, China
国际会议
广州
英文
37-40
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）