混炼方式对螺旋纳米碳纤维增强天然橡胶复合材料力学性能的影响

采用干法和湿法两种混炼工艺制备了螺旋纳米碳纤维(HCNFs)/炭黑(CB)/天然橡胶(NR)复合材料,通过扫描电镜、拉伸试验机和应变扫描仪分别对所制备复合材料的界面形貌、力学性能和Payne效应进行了测试分析,考察了混炼方式对复合材料宏观力学性能及Payne效应的影响。结果表明,与纯CB填料相比,在干湿两种混炼方式下,添加适量的HCNFs(1～6份)能提高HCNFs/CB/NR复合材料的300%定伸应力、扯断伸长率、拉伸强度和硬度。与干法混炼相比,湿法混炼能明显增强HCNFs/CB/NR复合材料的Payne效应,并提升在HCNFs高添加量(2～6份)条件下的拉伸强度和扯断伸长率,这主要源于湿法混炼能够有效改善HCNFs在橡胶基质中的分散性。

Effect of mixing methods on mechanical properties of helical carbon nanofibers reinforced natural rubber

Helical carbon nanofibers(HCNFs)/carbon black(CB)/natural rubber(NR)composites were prepared by dry and wet mixing methods.The interface morphology,mechanical properties and Payne effect of the composites were characterized by using field emission scanning electron microscopy,tensile testing machine and strain scanner,respectively.The effect of mixing methods on macroscopic mechanical properties and Payne effect of the composites were discussed in detail.The results showed that compared with pure CB filler,adding appropriate amount of HCNFs(1-6 phr)could improve modulus at 300%,elongation at break,tensile strength and hardness of HCNFs/CB/NR composites under dry and wet mixing conditions.Compared with dry mixing method,wet mixing could enhance significantly the Payne effect of HCNFs/CB/NR composite and also increase tensile strength and elongation at break of the composites with high addition amount of HCNFs(2-6 phr).This was mainly due to the fact that wet mixing could effectively improve the dispersion of HCNFs in rubber matrix.