碳纳米管增强天然橡胶动态疲劳及耐磨性能研究

发布时间：2018-01-20 08:51

本文关键词： 天然橡胶碳纳米管疲劳性能裂纹扩展耐磨性能　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳纳米管优越的物理机械性能使其成为橡胶增强的理想填料。但是国内外对于碳纳米管/天然橡胶复合材料动态疲劳性能的研究鲜有报道,而橡胶的疲劳性能直接决定了橡胶制品在动态条件下使用的耐久性、安全性与可靠性。本课题旨在探索碳纳米管对天然橡胶疲劳性能的影响和疲劳机理。针对以上的实验目标,开展的主要工作和结果如下：1.采用裂纹扩展法,研究了在20%-100%疲劳应变范围内,填充碳纳米管(1、3、5份)对天然橡胶动态疲劳性能的影响,并分别与相似硬度下炭黑(10、20、35份)增强的天然橡胶材料疲劳性能进行了对比。测定了1mm预割口的长条状试样的在动态循环载荷下的疲劳性能。结果发现：碳纳米管的加入对天然橡胶疲劳扩展的影响呈现两种相反的规律。在低疲劳应变范围(20%-40%)且较低的碳纳米管填充量(小于3份)下,碳纳米管/天然橡胶复合材料的抗疲劳能力优于相似硬度下炭黑/天然橡胶复合材料的抗疲劳能力；在高疲劳应变范围(40%-100%)下,碳纳米管/天然橡胶复合材料的疲劳优势不明显。在高硬度下,碳纳米管增强天然橡胶的材料疲劳寿命小于相似硬度下炭黑增强的天然橡胶,且硬度越大,差距越明显。从撕裂能角度分析,碳纳米管/天然橡胶体系的裂纹扩展速度与撕裂能之间关系的变化规律与炭黑增强天然橡胶体系不同。随着碳纳米管填充量的增加,碳纳米管/天然橡胶体系的裂纹增长速度随着撕裂能的增大而增大；而炭黑填充量的增加,炭黑/天然橡胶体系的裂纹增长速度随着撕裂能的增大而降低。为了进一步分析造成上述结果的原因,论文详细分析了填料对橡胶材料粘弹性、应变诱导结晶、裂纹偏转等方面的影响。2.本课题还着眼于碳纳米管/炭黑/天然橡胶复合材料的疲劳性能研究。在炭黑/天然橡胶体系中,在保持填料总份量不变的前提下,采用1、2、3、4、5份碳纳米管等量替代相同质量份数的炭黑。采用预割口长条状试样、屈挠疲劳试样、哑铃状伸张疲劳试样,研究碳纳米管/炭黑/天然橡胶复合材料的抗疲劳能力。研究发现：填充少量碳纳米管(1-2)份的天然橡胶能够与引发裂纹偏转,延长裂纹扩展路径,提高撕裂能,疲劳性能和抗切割性能优于炭黑增强天然橡胶。
[Abstract]:The excellent physical and mechanical properties of carbon nanotubes make them an ideal filler for rubber reinforcement. However, there are few reports on the dynamic fatigue properties of carbon nanotubes / natural rubber composites at home and abroad. The fatigue performance of rubber directly determines the durability of rubber products under dynamic conditions. Safety and reliability. The purpose of this project is to explore the effect of carbon nanotubes on the fatigue properties and fatigue mechanism of natural rubber. According to the above experimental objectives, the main work and results are as follows: 1. Crack propagation method is adopted. The effect of filling carbon nanotubes (CNTs) on the dynamic fatigue properties of natural rubber was studied in the range of 20% -100% fatigue strain. 35). The fatigue properties of the reinforced natural rubber materials were compared. The fatigue properties of the long strip specimens with 1mm precutting opening under dynamic cyclic loading were measured. The results showed that:. The effects of carbon nanotubes on the fatigue growth of natural rubber show two opposite laws. 20-40) and a lower amount of carbon nanotubes (less than 3 parts). The fatigue resistance of carbon nanotubes / natural rubber composites is better than that of carbon black / natural rubber composites with similar hardness. Under the high fatigue strain range of 40 to 100, the fatigue advantage of CNTs / NRRP composites is not obvious. The fatigue life of carbon nanotube reinforced natural rubber is smaller than that of carbon black reinforced natural rubber with similar hardness, and the larger the hardness, the more obvious the gap is. The relationship between crack growth rate and tear energy of CNT / NBR system is different from that of carbon black reinforced natural rubber system. The crack growth rate of carbon nanotube / natural rubber system increases with the increase of tear energy. However, with the increase of carbon black content, the crack growth rate of carbon black / natural rubber system decreases with the increase of tear energy. In this paper, the viscoelasticity and strain induced crystallization of fillers on rubber materials were analyzed in detail. The effects of crack deflection. 2. The fatigue properties of carbon nanotubes / carbon black / natural rubber composites are also studied. In carbon black / natural rubber system. On the premise of keeping the total content of filler unchanged, the carbon black with the same mass fraction was replaced by 5 carbon nanotubes of 1 / 2 / 3 / 4 / 5 carbon nanotube. The long strip specimen with pre-cutting mouth was used to flexure fatigue specimen. The fatigue resistance of carbon nanotubes / carbon black / natural rubber composites was studied by dumbbell tensile fatigue test. It was found that natural rubber filled with a small amount of carbon nanotubes (CNTs) 1-2) could deflect from the initiation of cracks. The crack propagation path, tear energy, fatigue property and cutting resistance are better than that of carbon black reinforced natural rubber.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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