| The content of nutrient elements especially N, P, K in soils can influence photosynthesis and growth for rubber tree, then the content protein in natural rubber. Fixed for rubber tree, the determination of N, P, K in soils and the protein content in natural rubber, under natural conditions, using SAS9.0statistical analysis software, regression analysis of the relationship between the protein content with the content of N, P, K in soil by using correlation and linear. The results showed that, the correlation of N content in soil with protein content in natural rubber is significant; the content of P, K with protein content in natural rubber latex is no significant correlation. In order to produce low protein natural rubber by reducing the N content in the soil, that has low heat resistance, low rolling resistance, being used in the preparation of green tire.The rubber particle is essential material of rubber tree protease catalyzed synthesis with protein membrane, so the protein is required by hydrocarbon synthesis in rubber tree. Pineapple juice contains nutrients and malic acid, citric acid, and bro-melain that can to degradate protein in natural rubber. The pineapple juice of peel, stem of processing waste, is added directly to the natural rubber latex, organic acid and microorganisms with nutriment to coagulate natural rubber, pineapple protease can degrade the protein in natural rubber, that combine the natural rubber latex coagulated and degradation of protein to preparate low protein natural rubber. The results show that, the1:10quality of pineapple juice, after40h stored at room temperature, can coagulate natural rubber latex with ammonia content of0.3%, and reduce the protein content of natural rubber latex from1.96%to1.17%, the removal rate reached40.31%. The mechanical properties, heat aging properties of the vulcanized decreased slightly.Starch and SiO2is filled in rubber to prepare the tire surface rubber with the advantages of small rolling resistance, big wet grip characteristics etc.. Starch, sodium silicate and natural rubber latex as the main raw material, then to hydrolysis of starch, and then mixed with sodium silicate solution, to get starch/SiO2composite particles with situ technology, and blended with natural rubber latex, solidification and the degradation of protein with pineapple juice, to prepared starch/SiO2/DPNR composite with condensation. Research on the relation of between starch/SiO2dosage, Na2SiO3·9H2O concentration, reaction temperature, reaction time, the dosage of silane coupling agent TESPT, inhibitors of NaCl, surface active agent CTAB, dispersant EDTA-2Na with orthogonal experiment, two quadratic regression orthogonal rotation design, starch/SiO2filling amount and the properties of starch/SiO2/DPNR composites. To get the best conditions by analysis the mechanical properties and laser particle size analyzer with infrared (IR), polarized optical microscopy, scanning electron microscopy(SEM), transmission electron microscopy(TEM), the structure and properties of X-ray diffraction, thermo-gravimetric analysis and other modern test methods. The results show that, the particle diameter of starch/SiC>2composite particles is between300nm-500nm, with good compatibility and dispersion with the natural rubber matrix. In range of this experiment, the optimum process conditions are: Starch/SiO2ratio is1:2, Na2SiO3·9H2O concentration is217g/L, reaction temperature is95℃, reaction time is40min; the dosage of silane coupling agent TESPT is6.34%, inhibitor NaCl is12.36%, surfactant CTAB is0.21%, dispersion EDTA-2Na is0.23%as a benchmark of the starch/SiO2composite particle theory dosage, and the theory filling amount of starch/SiO2composite particle is30, The fixture strength at300%is6.53MPa, the fixture tensile at500%is20.19MPa, the tensile strength is26.08MPa, the tear strength is55.45KN/m, the mechanical properties of starch/SiO2/DPNR composites are excellent. |
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