摘要:
以十八烷基三甲基溴化铵为插层处理剂改性蒙脱土。分别采用有机蒙脱土(C18-MMT) 和Na-蒙脱土(Na-MMT) 填充补强丁苯橡胶, 用XRD 和TEM 对复合材料的结构进行表征。结果表明: 蒙脱土在橡胶基体中的分散取决于蒙脱土的亲油性, 亲油性越强, 蒙脱土的片层在橡胶中的分散越均匀, 完全有机化处理的蒙脱土能够被剥离成厚度为20 nm 左右的片层并均匀分散在橡胶基体中。蒙脱土的存在对橡胶的硫化反应有一定的影响, 有机蒙脱土对橡胶硫化反应有催化作用, 但不改变硫化反应的活化能; Na-蒙脱土片层阻碍了橡胶的硫化交联, 使交联反应对温度的敏感性降低, 导致表观活化能减小。有机蒙脱土填充补强丁苯橡胶, 由于提高了橡胶的交联密度, 同时有机蒙脱土具有高比表面积和滑移性, 大大提高了橡胶的机械性能, 其拉伸强度和300 %定伸应力与炭黑N330 补强橡胶相当, 而断裂伸长率较炭黑补强橡胶有大幅度的提高, 在替代炭黑作为橡胶的补强剂方面具有广泛的应用前景。
关键词:
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蒙脱土
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丁苯橡胶
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补强
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硫化
Abstract:
SBR/ C18MMT and SBR/ Na-MMT composites were prepared through a melt intercalation process.The result s of XRD and TEM observation show that the dispersion of montmorillonite layers in SBR mat rix is determined by the hydrophobic property of the layers. Organic t reated montmorillonite could be exfoliated into layerswith about 20nm in thickness and uniformly dispersed in the SBR mat rix. The effect s of montmorillonite on the vulcanization reaction of SBR were determined by DSC method. The vulcanization curves show that the existence of C18-MMT accelerates the vulcanization reaction and the activation energy is not changed. For the SBR reinforced by Na-MMT , the vulcanization was impeded and the sensitivity of reaction to temperature was decreased , which resulted inthe decrease of apparent activity energy. Due to the nanoscale dispersion of layers of C18-MMT and the enhancedcrosslinking density of rubber mat rix , the mechanical properties of SBR dramatically increase. The tensile st rengthand 300 % modulus of SBR/ C18-MMT nanocomposite were correspondent to the SBR reinforced by equal content ofcarbon black N330 while the elongation at the break of the nanocomposite was much higher , which is related to theslipping and oriented arranging of the C18-MMT layers in the composite under tension.
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