Study On Cassava Starch/NR Composite

The composite of Cassava Starch and NR was prepared by Co-Coagulation method using Cassava Starch and Natural Rubber Latex as main raw materials. Firstly starch was pasting or dealt with xanthate,then coagulated with natural rubber latex to prepare the composite. The effects of prepared conditions such as stirring time, stirring rate,starch concentration and dosage of Cassava Starch on mechanical properties of Cassava Starch/NR composite were investigated. The composite prepared with paste starch coagulation method was contrasted with the ones prepared with traditional blending and starch coagulation. Paste starch was modified with coupling agent—KH550, Phenolic Resin and PY complexes, and modification effect of kinds and concentration of modification agent on composite was studied.The structure and properties of Cassava Starch/NR composites were determined with FTIR,SEM,TEM,X-ray,DSC,TG,RPA and DMA. The results showed the optimum prepared condition was stirring rate 450r/min , stirring time 30 min and starch concentration 5%. Modification effect of coupling agent KH550 on Cassava Starch/NR composite was not obvious. However, obvious modification effects of RF and PY complexes on composite were observed, the interface of starch and rubber was strengthened and the structure and properties of composite improved. The composites achieved excellent mechanical properties when the dosage of Cassava Starch was 20 shares and RF 2.5 shares.The crystal structure of starch particles in the composite prepared with co-coagulation method disappeared and transferred to amorphous state. After starch was pasted or xanthated, the dispersion degree of starch particles in NR matrix increased and particles dimension dramatically decreased. The generalized properties of composite prepared with paste starch coagulation method dwarfed the ones prepared with traditional blending and starch coagulation. After Cassava Starch was xanthated, its strengthen effect on NR was obviously observed and the properties of composite improved greatly.