Investigations On The Hybrid Modification Of Microcrystalline Cellulose And Its Effects On The Properties Of Rubber Compounds

Cellulose is the most abundant biomaterial on the earth,and microcrystalline cellulose(MCC)can be made by cellulose via acidolysis.MCC had high strength and had the potential to be used as reinforcing filler in rubber materials.However,its big size and strong polarity make it bad interaction with nonpolar rubber matrix.A MCC-ZnO hybrid material was prepared by micro-reactor and sol-gel technique when zinc acetate was used as precursor.And then the MCCC-ZnO was used in SBR/SiO2 composites by replacing partial silica to investigate its effects on the processing,mechanical and dynamic mechanical properties of the tire tread compounds.First,the swelling efficiency of different agents,8%wt NaOH and urea aqueous solution,on cellulose was studied and measured by Fourier Infrared Spectrum(FTIR),X-ray diffraction(XRD),Thermogravimetic Analysis(TGA)and Scanning Electronic Microscope(SEM).The results showed that both NaOH and urea aqueous solution could swell MCC.The crystallinity of NaOH swollen MCC obviously decreased,but there was a slight growth for urea aqueous solution.The content of hydrogen bond of MCC decreased after swollen by NaOH as shown by FTIR spectrogram.TGA curves indicated that the thermal stability of MCC swollen by NaOH dropped,with decomposition temperature declining from 360.5°C to 279°C,while the thermal stability of MCC swollen by urea solution slightly increased.Besides,effect of different amount of swollen MCC in ESBR/SSBR/SiO2 tread composites was studied,and the results showed that the processing property,filler dispersion and anti-temperature rising property of rubber were improved and better with more dosage.But their physio-mechanical properties were decreased seriously.Finally,the MCC-nano ZnO hybrids with various morphologies were fabricated by different reaction conditions after swelling processes.The results showed that the shape of ZnO could be controlled from sphere to rod-like,and then to fibre-like with the different drying time after a swelling process.The shapes of ZnO on the hybrids could also be controlled to be rod-like by changing the pH value at the end of sol-gel reaction.The morphology of ZnO was mainly sphere on the MCC hybrids when swollen by urea solution.After applying the MCC/nano-ZnO hybrids in tread composites,compared with the unmodified MCC,the dispersion of filler in matrix was better,and the rolling resistance and wet-skid properties of vulcanizates were also improved.Compared with hybrids swollen by NaOH,those swollen by urea had better physio-mechanical properties of the vulcanizates.