Preparation And Applications Of Purified Cellulose Fibrils From Rubber Wood

Rubber wood contains about 50%cellulose.Cellulose can be extracted by certain means and then prepared into cellulose-based materials by physical or chemical methods.It not only provides a new idea for the utilization of rubber wood,but also brings certain economic benefits.In this paper,purified cellulose(PCF)was extracted from rubber wood processing residues.The morphology,crystalline structure,chemical functional groups and thermal stability of PCF were evaluated.On this basis,PCF based electrode materials and adsorbents were explored,respectively.Firstly,cellulose nanofibrils(CNF)were prepared via high-intensity ultrasonication from PCF,and then mixed with manganese dioxide(MnO2)and carbon nanotubes(CNTs).Electrode materials were prepared by vacuum filtration,the electrochemical properties of the electrode materials were analysised preliminarily.In addition,carboxymethyl cellulose(CMC)was obtained by carboxymethylation of PCF,which was used to fabricate pH-sensitive hydrogels by reverse suspension polymerization.The adsorption performances of hydrogels for rhodamine B(RhB)was evaluated preliminarily.What is more,cellulose nanocrystals(CNC)were obtained by acid hydrolysis of PCF,succinic anhydride(SAA)was grafted onto CNC to obtain CS,and then cetyltrimethylammonium bromide(CTMAB)was coated on CS to obtain drug sustained-release carrier CC.The release performances of HES from drug release carrier CC were preliminarily explored.The main conclusions are as follows:1)Using rubber wood as native material,PCF was obtained by chemical treatment.Compared with poplar wood,rubber wood has higher cellulose content,and the obtained rubber wood PCF has similar micro-morphology,chemical structure,crystalline structure and thermal stability with PCF from poplar wood.2)CNF was prepared by high intensity ultrasonication based on PCF.CNF/MnO2/CNTs flexible electrode materials were prepared using CNF as structural support,CNTs and MnO2 as conductive active materials.The electrochemical tests showed that the electrode materials had good electrochemical properties.At the same time,the electrode material also has certain soft deformation ability.Therefore,the CNF/MnO2/CNTs electrode material is a flexible electrode material with good performance.3)CMC was prepared based on PCF.The hydrogel was prepared by inverse suspension method.The swelling property of the hydrogel increased with the increase of the pH value of the buffer solution,and showed certain pH-sensitivity.The prepared hydrogel is suitable for treating high concentration RhB dye wastewater with alkaline condition.4)CNC was prepared based on PCF.CNC was modified by grafting SAA(named as CS).On this basis,CTMAB was coated on the surface of CS by electrostatic force to obtain the drug delivery carrier material(labled as CC).The CC@HES drug delivery system was prepared with CC as the drug delivery carrier material and hydrophobic drug HES as the model drug,and its release properties in vitro were analyzed.The results showed that the percentage of cumulative release of HES in the CC@HES drug delivery system was higher in a weakly alkaline environment(pH 7.4).The release of HES from the CC@HES drug delivery system is in accordance with the Peppas empirical equation and belongs to the Fickian diffusion mechanism.