The Research Of Modified Waste Cotton Cellulose Used In Styrene-butadiene Rubber

The development of green tire prompted silica substantial growth. Preparation of alow-cost, renewable cellulose and other plant resources rubber filler has become a hot research, because of its surface groups similar to the silica. Waste cotton fiber came from human production and life with low price, so there is an urgent need to re-utilization. This paper used waste cotton fiber prepared modified cellulose, and explored the relationship between the structure and properties of the rubber/cellulose composite, and it would be a obvious theoretical and practical significance.In this thesis, microcrystalline cellulose (MCC) was prepared by acid hydrolysis, or a combination of acid hydrolysis and alkaline hydrolysis form the waste cotton fiber, and the effect of hydrolysis conditions on structure of MCC was also investigated; Than based on previous research, a new environmentally friendly agriculturalbyproducts Cashew Nut Shell Oil with a reactive epoxy group(ECNSL) was chosed as modifying agent, and used aqueous phase milling process to modify MCC; The effect of structure and amount of the modified MCC(MMCC) on structure and performance MMCC/styrene-butadienerubber (SBR) composite was discussed, and the silica comparison test also be set; Throught the method of in-situ compatibilization, the effect of three kinds of compatibilizers, such as ECNSL,60NSF(Light-colored mixture of aliphatic hydrocarbon resin), SBR-g-MAH (styrene-butadiene-graft-maleic anhydride) and RX-80(alkylphenol with various structure, formaldehyde and proper modifier compounds) and their addition level on interfacial adhesion between the MCC and the rubber phase and the mechanical properties of MCC/SBR composite were investigated. Traditional test methods and some modern analytical techniques, i.e. infrared spectroscopy (FT-IR), differential shows scanning calorimetry analysis instrument (DTG), X ray diffraction instrument (XRD), rubber dynamic mechanical analysis analyzer (DMA) and scanning electron microscope (SEM) were used to characterize the structure of the composite material of the MCC, MMCC and MCC/SBR. The study results showed that:(1) By laser particle size analyzer on MCC particle size and particle size distribution analysis prepared by different sulfuric acid hydrolysis of waste cotton fiber found that the best hydrolysis process is8%of the concentration of sulfuric acid, hydrolysis time2h. and temperature80℃, the MCC particle size D50was23.60p.m. and particle size distribution in the range10μm of50μm;5%NaOH pretreatment of waste cotton fibers and then hydrolysis, the particle size D50of was10.23pm. particle size distribution is mainly in the5μm to70pm. XRD studies found that XRD diffraction angle (20) of cotton fibers and MCC were mainly concentrated in the range of10to45degree and had the typical structure of cellulose crystal I.(2) MMCC FT-IR spectra in777,911,1260and3014cm-1for rendering the infrared peak, which is the characteristic peaks of epoxy group on ECNSL;2850.2925,1601,1580cm-1these strong peak in MMCC is the modifier of long carbon chain and a benzene ring Reference modifier ECNSL successfully grafted to the surface of the MCC particles did not occur, while for the IR spectra of the MCC; the MMCC and MCC DTG spectrum display MMCCthermal weight loss, and this is the MCC the graft ECNSL long carbon chain and the result of the reduced heat resistance, which also indirectly be described ECNSL of successfully grafted to the MCC particles. The MMCC SEM analysis results showed that MCC particle diameter becomes small and the particles become fluffy after modified by ECNSL.(3) In the range of20to50phr, with the increase in the amount of MCC, the tensile strength and elongation at break of MCC/SBR composite downward trend, hardness and tear strength increasing as the increase of content of the MCC. Compared with the MCC, MMCC improved the processability and mechanical properties of SBR, MMCC modified by12.5wt%ECNSL had better reinforcing properties. The sample filled with MMCC had smaller minimum torque and the maximum torque than sillica, and decreases with the modifier ECNSL increase. But with the increased ECNSL usage the rubber scorch time (t10) and optimum cure time (t90) increased.(4) DMA analysis showed, SBR were added by MMCC and silica at near60℃tanθ almost the same, and MMCC/SBR composite at near0℃tanθ bigger than adding silica SBR rubber, it mean to had better wet skid resistance: but Akron wear of MMCC/SBR composite slightly larger than silica. (5) In the dosage compatibilizer range of0～10.0phr. as the increase of ECNSL,60NSF.SBR-g-MAH and RX-80. hardness and300%modulus of MCC/SBR composite continue to reduce, elongation at breakrate and tearing permanent deformation always rising, the tensile strength and tear strength tended to first increase and then decrease. Compared with ECNSL,60NSF and RX-80, the mechanical properties of MCC/SBR composite could be significantly improved by adding SBR-g-MAH.(6) SEM analysis showed that after MCC modified by ECNSL, the compatibility and dispersion in SBR were significantly improved; adding an appropriate amount of compatibilizing agent ECNSL,60NSF, SBR-g-MAH and RX-80can improve the interface between the MCC and SBR matrix compatibility.