Study On Modification Behavior And Application Of Calcium Sulfate Whisker

Calcium sulfate whisker is a kind of fibrous single crystals with uniform cross-section,complete shape and perfect internal structure.Due to the excellent performance,good compatibility and regeneration,low toxicity,low manufacturing cost of calcium sulfate whisker,the calcium sulfate whisker can be widely used to prepare polymeric composites.But one of the most problematic issue of calcium sulfate whisker is the hydrophilic property which makes it very easy to aggregate block.Therefore,it is important to study the relationship between the modification behavior of calcium sulfate whisker and the polymer matrix,and it is of great importance to the application of calcium sulfate whisker.In this study,calcium sulfate whisker is raw materials,the modification behavior of calcium sulfate whisker was observed by means of SEM,TEM and FT-IR.At the same time,the modified calcium sulfate whisker was applied to rubber and asphalt,and the effect of application was observed.Under the condition of this experiment,we get the following conclusions:(1)Sodium stearate,stearic acid and sodium oleic acid can modify the surface of calcium sulfate whisker,the modification effect of stearic acid is better than sodium stearate and sodium oleic.(2)The optimal conditions to modify calcium sulfate whisker is as following:the surfactant concentration is 4%,the slurry concentration is 10%,the modification temperature is 90?,the modification time is 30min.Under this condition,the active ratio is 0.636,the contact angle is 110°.(3)The modified calcium sulfate whisker added to rubber can improve the hardness,tensile strength and elongation at break of rubber markedly.The rubber can achieve a better property when the calcium sulfate whisker is modified under optimal conditions,which the shore hardness is 67°,the tensile strength at break is 21.92MPa,the elongation at break is 619%.(4)The modified calcium sulfate whisker added to asphalt can improve the high temperature stability of asphalt.The asphalt performance meets the technical requirements of road asphalt when the amount of calcium sulfate whisker is 10%,under this condition,the penetration is 7.96mm,the softening point is 49.11 ?,the ductility is 65cm.