Preparation Of Bagasse Nano-fibrillated Cellulose And Their Applications In Films Materials

agasse, an agricultural waste, is a major by-product of sugarcane in sugar industry. At present, only a small part of the bagasse is used to the paper industry, most of them are used as the boiler fuel, which has caused a great waste of resources and environmental pollution. In order to expand the scope of application of bagasse and increase their added value, bagasse pulp was treated by the mature TEMPO mediated oxidation and the oxidation law was studied; NFC were prepared from oxidized cellulose via high-pressure homogeneous processing and the diameter of NFC and its crystallinity degree was characterized; by way of physical blending, the bagasse NFC/PVA films were prepared; By the vacuum filtration, NFC films were made from suspension and then the NFC/PMMA composites were prepared by impregnation method. The results are showed as follows. 1. A great deal of carboxylate groups were introduced into the macromolecular chain of bagasse cellulose after oxidation with TEMPO/Na Cl O/Na Br. Carboxylate content increased with the increase of Na Cl O used. Carboxylate content of eucalyptus cellulose was 1.01 mmol/g when the dose of Na Cl O was 7.0 mmol/g. FTIR patterns of the oxidized bagasse cellulose showed that the peak of carbonyl diffraction at 1720 cm-1 was strengthened which indicated that carboxylate groups were introduced. X-ray diffraction patterns showed, cellulose crystalline structure was unchanged after oxidation. TG analysis showed that the thermal stability of the oxidized bagasse cellulose decreased. 2. The well dispersed NFC suspension was prepared by high-pressure homogeneous processing. TEM and AFM analysis showed that the minimum diameter of NFC was 20 nm when the dose of Na Cl O was 7.0 mmol/g. FT-IR and TG spectra showed that the chemical structure and the thermal stability of NFC were almost unchanged. XRD spectra showed that high-pressure homogeneous processing decreased the degree of crystallinity. 3. The bagasse NFC/PVA films were prepared by way of physical blending. SEM images showed that NFC and PVA can be mixed uniformly, what is more, the surface of NFC/PVA films became rough with the increase of NFC added. FT-IR and XRD spectra showed that the chemical structure and the crystallinity of NFC /PVA were almost unchanged. The tensile test results showed that the mechanical properties of the composite gel films were the best when the dose of NFC was 6 wt%, once the dose of NFC surpassed 6 wt%, the mechanical properties got worse because of the NFC flocculation. 4. The NFC suspension was made into NFC sheet by vacuum filtration, and the NFC/ PMMA nanocomposites sheet was successfully fabricated by immersing the NFC sheet into PMMA solution. SEM images showed that NFC fracture surfaces appeared compact structure and PMMA compounded in the surface of NFC closely. The tensile test results showed that the mechanical properties of the NFC/PMMA composites became stronger. The transparency of composites NP-4, NP-5 and NP-6 reduced slightly when compared with neat PMMA film’s. This laid the foundation of its acting as display substrate material.