Manufacture Of Nano-crvstalline Cellulose From Bamboo Pulp

China called“the country of bamboo”has abundant bamboo resources, but there is fewresearches on developing bamboo resources, furthermore nano-crystalline cellulose (NCC) hashigher value and could be applied on various fields. So the method nano-crystalline cellulose(NCC) was prepared from bamboo dissolving pulp can increase comprehensive utilizationvalue of bamboo resources.In this research, Nano-crystalline cellulose (NCC) was achieved from bamboo dissolvingpulp by means of acid hydrolysis and milling enzymolysis and PFI enzymolysis. Processingparameters were optimized by experimental design using a response surface method andorthogonal experiment based on single factor experiment. NCC yield of55.83%can beachieved under the optimal hydrolysis conditions, i.e. temperature of53℃, time of128min,the concentration of sulfuric acid of60%. NCC yield of17.98%can be achieved under theoptimal milling enzymolysis conditions, i.e. temperature of50℃, time of24h, theconsumption of milling enzyme of9.6FPU. NCC yield of19.13%can be achieved under theoptimal PFI enzymolysis conditions, i.e. the speed of PFI9000r, temperature of50℃, time of3d, the consumption of PFI enzyme of2.736FPUThe bamboo pulp、 pretreated bamboo pulp and obtained NCC products werecharacterized using scanning electron microscope(SEM)、 an atomic forcemicroscope(AFM)、 a X-ray diffraction (XRD)、 a Fourier transformation infraredspectroscopy(FTIR) and a thermogravimetric analyzer (TGA). Results show that, the crushedbamboo pulp still keeps the original cellulose structure and parts of cellulose of long chainwere cut off. The milling treated Bamboo pulp were turned into almost spherical particles,approximately5-10nm. The cellulose of pretreated bamboo pulp by PFI enzyme were cut offand turned into brush wire on the surface of cellulose. The size of PFI enzymolyed celluloseresidue was smaller than that of PFI pre-treated cellulose, approximately less than20um inlength and less than several in width. As we can see, The largest average size of spherical NCC achieved by milling enzymolysis compared with that by acid hydrolysis and PFIenzymolysis, as length between800-1000nm,the smallest average size of NCC achieved byacid hydrolysis was as length between100-200nm, and width less than10nm. The averagesize of spherical NCC achieved by PFI enzymolysis was as length between400-600nm. XRDindicates that bamboo、 pre-treated bamboo and NCC achieved were cellulose I. Bamboocrystallinity was64.27%, NCC crystallinity increases from64.27%to72.04%by acidhydrolysis and decreased from64.27%to43.34%by milling pre-treatment. Reasons can beexplained that milling pre-treatment destroyed the crystal structure of cellulose. NCCcrystallinity increases from64.27%to73.95%by PFI enzymolysis. Pre-treated bamboocrystallinity was always lower than bamboo crystallinity. FTIR indicates that bamboo、 pre-treated bamboo and NCC achieved had almost same characteristic absorbance peaks and allkeep the basic chemical structures of cellulose. As it can be seen in the thermogravimetricanalyzer (TGA), pre-treated bamboo and NCC achieved showed different thermal stabilityduring the different temperature range.thermal stability of pre-treated bamboo by PFI ishigher than that of bamboo pulp. Although pre-treated bamboo by milling and NCC achievedbegan initial degradation and sharp weight loss at lower temperature than bamboo pulp, theresidual quality of pre-treated bamboo by other methods and NCC achieved at the end ofthermal decomposition were larger than that of bamboo pulp.The hydrolysate achieve d during t optimal milling enzymolysis conditions swas analysedusing high efficiency liquid chromatography. Results indicated that the main reducing sugar ofhydrolysate was glucose. The concentration of glucose during milling and FPI enzymolysiswere70.13%and71.06%. The concentration of cellobiose and xylose during millingenzymolysis and FPI enzymolysis were16.19%、11.55%、12.39%and7.68%. Above allreducing sugar of hydrolysate can be applied to develop glycosylase material.