Preparation And Properties Of High Oil Absorption Resin Based On Spherical Cellulose Nanocrystal

High oil-absorption resin is a new kind of self-swelling oil-absorbing material with low degree of crosslinking,which can effectively solve the oil leakage problem in place of traditional materials.In this paper,spherical cellulose submicron crystal(SCMC)was prepared by sulfuric acid hydrolysis of microcrystalline cellulose,and then it was grafted with methyl acrylate and methyl methacrylate to prepare SCMC-g-PMA and SCMC-g-P(MA-co-PMMA)high oil absorption resin.Fourier Transform Infrared Spectroscopy,X-ray Diffraction,Thermogravimetric Analysis,Transmission Electron Microscopy,Scanning Electron Microscope and oil absorption performance test were used to characterize the structure,crystal form,morphology and oil absorption properties of the resins.The effects of the monomer mass ratio,initiator,crosslinker,dispersant polymerization temperature and graft ratio on the oil absorption performance of the resin were studied in detail,and then the optimum reaction conditions was determined.The oil absorption kinetics of the two kind resin was also studied.Based on the above research,the conclusions of this paper were summarized as follows:(1)The particle diameter of SCMC ranged from 150 to 330 nm,and its chemical structure was basically the same as that of microcrystalline cellulose.The crystal structure of SCMC particles was still cellulose I?,but the crystallinity of SCMC increased from 71.4%to 78.1%,and the thermal decomposition temperature(T_max)decreased from 237°C to 227°C.The synthesis principle of SCMC could be explained by the mechanism of hydrolysis of sulfuric acid:H⁺first selectively attacks the amorphous region of cellulose in the process of hydrolysis,and the microcrystalline cellulose is gradually cracked into irregularly submicron particles.(2)The crystal structure of SCMC-g-PMA was still cellulose I?,but the crystallinity decreased from 78.1%to 53.9%,and the T_max increased from 227°C to 296°C.The surface of SCMC was rough,which was beneficial to the combination of resin and oil molecules.SCMC-g-PMA had good oil absorption performance.The maximum oil absorption rate of SCMC-g-PMA to carbon tetrachloride was 8.1 g/g.The optimal experimental reaction conditions were:the molar ratio of MA/SCMC was 6:1,initiator dosage was 1.2 wt%(accounting for the mass of monomer),the amount of the crosslinking agent was 1.6 wt%,the amount of the dispersing agent was 1.6 wt%,the polymerization temperature was 80°C and the graft ratio was 0.79.The kinetics of SCMC-g-PMA oil absorption resin was in conformity with the first-order equation.The oil absorption kinetics of SCMC-g-PMA conformed to the dynamic first-order equation,and the kinetic constant was 0.0948 min^-1,it suggested that the oil absorption process was mainly determined by the diffusion of oil molecules on the surface of the resin.(3)The crystalline region of SCMC-g-P(MA-co-PMMA)was destroyed,T_max increased from 227°C to 305°C,and its larger specific surface area enlarged the contact area between oil and resin.SCMC-g-P(MA-co-PMMA)had good oil absorption performance.The maximum oil absorption rate of SCMC-g-P(MA-co-PMMA)to carbon tetrachloride was 8.5 g/g.The optimal experimental reaction conditions were:the MA/MMA molar ratio was 1:0.5,the initiator dosage was 1.2 wt%(accounting for the mass of monomer),the amount of the crosslinking agent was 1.6 wt%,the amount of the dispersing agent was 1.6 wt%,and the polymerization temperature was 80°C and the graft ratio was 0.78.The kinetics of SCMC-g-P(MA-co-PMMA)oil absorption resin was in conformity with the first-order equation.The oil absorption kinetics of SCMC-g-P(MA-co-PMMA)conformed to the dynamic first-order equation,and the kinetic constant was 0.0996 min^-1,it suggested that the compatibility between SCMC-g-P(MA-co-PMMA)and carbon tetrachloride was higher in contrast with SCMC-g-PMA.In summary,SCMC with a spherical shape and submicron particle diameter,has a large surface area and can be used in the field of oil adsorption.Compared with general oil-absorbing resin(oil absorption rate less than 6 g/g),SCMC-g-PMA and SCMC-g-P(MA-co-PMMA)have good oil-absorbing properties,and their larger surface area is conducive to oil molecules adsorbing on the resin surface.