Study On Modification Of Nitrile Rubber By Calcium Sulfate / Cellulose Whisker

Nitrile rubber is mainly used as oil and seal products, and in order to improve its application properties, the study of rubber reinforcing modification, especially new fillers, places an important role. Calcium sulfate whisker and cellulose whisker are green, non-toxic and environmentally friendly rod sub-nanometer materials, which can reinforce the nitrile rubber, so it has theoretical and practical significance for these whiskers to be studied.Atmospheric acidification method was used to prepare calcium sulfate whiskers by using a kind of salt waste brine enriched in chloride ion, and acid hydrolysis method was used to prepare cellulose whiskers, and both of the influence factors of preparing these two whiskers were discussed. The preparation rules of calcium sulfate whisker were as follows, with the increase of reactants concentration, reaction time, temperature and the rotation speed, the aspect ratio of whisker was firstly increased and then decreased, and the pH value was hardly influenced. The preparation conditions of calcium sulfate whisker and cellulose whiskers were optimized. While the amount of substance concentration of solutes valued1M, the calcium sulfate whiskers were best prepared under70degree centigrade for30min, with pH value2and rotation speed150r/min, and when the mass proportion between cotton, pre-soaked by sodium hydroxide for2h, and the solvent is11:1, the cellulose whiskers were best prepared under55degree centigrade for30min. IR was used to verify the composition. XRD and SEM were respectively used to characterize the micro-structure. The results turned out that crystallinity of calcium sulfate whiskers was80%which was higher than the cellulose whiskers38.6%. The average diameter and length of both kinds of whiskers were measured by SEM with calcium sulfate whiskers average diameter1-5μm, length20-200μm and length-diameter40, while cellulose whiskers with length0.5-1μm and diameter20-200μm, respectively.Calcium sulfate whisker with length-diameter ratio of20,40, and60and cellulose whiskers were respectively used to reinforce NBR. The results showed that the performance of NBR was on the rise with the increase of the value of length-diameter ratio of calcium sulfate whiskers. Its heat resistance temperature increased by5degree centigrade, mass loss reduced3%, and anti-aging performance improved a lot. When the length-diameter ratio of the calcium sulfate whiskers was60, the reinforcement was the best. It improved the NBR tensile strength from2.72MPa to14.04MPa, the elongation at break from272%to592%, and shaw hardness from43to49. But when combined these two whiskers to reinforce the result was unsatisfied, the tensile strength was lower than single whisker, valuing.The reason why these two kinds of whiskers can modify NBR is while stretching NBR the whiskers will align along the force by enhancing the capability of NBR to withstand the stress. The mechanism is also related to the consistency between the whiskers and NBR which needs to be further studied.