科研之友
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摘要
Blend membranes of chitin/cellulose from 12: 50 to 12: 250 were successfully prepared from cotton linters in 1.5M NaOH/0.65M thirourea solution system. Two coagulation systems were used to compare with each other, one coagulating by 5 wt % H2SO4 (system H), and the other by 5 wt %) CaCl2 and then 5 wt % H2SO4 (system C). The morphology, crystallinity, thermal stabilities, and mechanical properties of the blend membranes were investigated by electron scanning microscopy, atomic absorption spectrophotometer, infrared spectroscope, elemental analysis, X-ray diffraction, different scanning calorimeter, and tensile tests. The cellulose/chitin blends exhibited a certain level of miscibility in the weight ratios tested. There were great differences between the two blends H coagulated with H2SO4 and C coagulated with CaCl2 and H2SO4, respectively. The membranes H have a denser structure, higher thermal stability, tensile strength (sigma(b)), and crystallinity (chi(c)), and values of sigma(b) (90 MPa for chitin/cellulose 12: 150) were significantly superior to that of both chitin and regenerated cellulose membrane. However, the blend membranes C have much better breaking elongations (epsilon) than that of membranes H, and relatively large pore size (2r(e), = 210 mum), owing to the removal of a water-soluble calcium complex of chitin as pore former from the membranes C. When the percentage content of chitin in the blends was from 5 to 7.5%, the values of breaking elongation for the blend membranes H and C all were higher than that of unblend membranes, respectively. The blends provide a promising way for application of chitin as a functional film or fiber in wet and dry states without derivates.
- 出版日期2002-11-21
- 单位武汉大学
