Green Fabrication Of Nano Cassava Dregs And Its Potential Application In Rubber

In view of the increasing shortage of non-renewable resources such as oil,we treated renewable resources-cassava dregs into nano cassava dregs(NCDs)by using a "green" method from the perspective of sustainable development.The NCDs was then compounded with natural rubber(NR)and carboxylated styrene-butadiene rubber(XSBR).It would be expected to partly substitute fillers such as carbon black,silica and so on.And theoretical and technical support for the high value utilization of cassava dregs would be given.NCDs were prepared via green methods in which CDs were treated by selected additives(NaOH,NaClO and H2O2)combined with three mechanical processes(ball mill,homogeneous,and ultrasonic).The composites of NCDs/NR-V、NCDs/NR and NCDs/XSBR were prepared via the low temperature vulcanizing and compounding.The microstructures of NCDs and composite material were characterized by Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),atomic force microscopy(AFM)、thermal gravimetric analysis(TGA)and particle size test.The mechanical properties and thermostability of compositematerial was tested as well.The main conclusions are as follows:(1).The optimum treatment condition for CDs was 15%H2O2(w/w)combined with three mechanical methods.The minimum particle size of NCDs was about 30 nm.It was found that the stability of NCDs was improved and the sedimentation rate of NCDs in suspension became slow compared with CDs.(2).For the non-polar NR system,the studies of cure-curves and tensile behavior of vulcanized NCDs/NR composites showed that the crosslinking density of rubber was increased by the addition of NCDs.The NCDs had reinforcement on the NR matrix.The NCDs reinforced NR showed optimal mechanical properties at 10 phr NCDs.In addition,the mechanical properties of the NCDs/NR-Vulcanized(NCDs/NR-V)were much better than that of the NCDs/NR.The highest tensile strength of NCDs/NR-V composites were 20 times of NCDs/NR compounds.(3).For the polar XSBR system,FT-IR results showed that the absorption peak of components had no apparent changes,suggesting that the interations between NCDs and XSBR were manily the physical adsorption interactions which enhanced the mechanical properties of the uncured NCDs/XSBR compounds.SEM images clearly showed that the NCDs were uniformly dispersed in the XSBR matrix.Mechanical performances and TGA results showed that with increasing NCDs content,the tear strength and elongation at break increased at first and then decreased,the addition of 20 phr NCDs had better reinforcing effect on the mechanical properties of the XSBR compounds.Similarly,the XSBR with 20phr NCDs showed good thermostability.However,when the amount of NCDs exceeded 30 phr,the mechanical performance of the XBSR compounds were dedreased due to the formation of NCDs aggregations at relative high loading levels.