Preparation, Properties Of Starch/Rubber Composites

NBR/starch, SBR/starch, NR/starch and CNBR/starch composites were prepared firstly by compounding rubber latex with starch paste and co-coagulating. The composites were compared with those composites by directly blending. The effects of kinds of starch, the concentration of starch paste, the amount of starch, the stability character of latex, the mixing time and velocity of starch/latex system on the compounding technique were studied in detail. Scanning electron microscopy and transmission electron microscopy showed that the size of starch particles was much smaller than that of the original starch. X-ray diffraction indicated that the crystalline of starch in rubber/starch composites by the above technique disappeared. In contrast to NBR/starch, SBR/starch, NR/starch and CNBR/starch composites by directly blending, the corresponding NBR/starch, SBR/starch, NR/starch and CNBR/starch composites by co-coagulating exhibited excellent mechanical properties.The morphology and mechanical properties of starch/rubber composites with different amount of butadienstyrenevinyl pyridine rubber were researched. Starch/ SBR composites were prepared by co-coagulating, and the effect of two coupling agents Bis-(γ-triethoxysilylpropyl)-tetrasulphide (Si-69) , 3-aminophopyltrie-thoxysilane (KH-550) and Resorcinol-Formaldebyde (RF) on structure and properties of Starch/SBR composites were investigated. All of the three modifiers reduced the scorch time of the compounds, especially KH550. RPA of the compounds showed that the modulus of compounds combining RF and KH550 was the highest. Scanning Electron Microscope (SEM) of starch/SBR composites showed RF enhanced the interfacial adhesion between filler and rubber obviously. SEM photographs showed that Si69 improved the crosslinking density of rubber matrix, so brittle rupture happened and the dispersion of starch was hard to observe.