碳纳米管填充天然橡胶复合材料导热性能的研究

发布时间：2018-03-11 09:31

本文选题：天然橡胶　切入点：碳纳米管　出处：《青岛科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,导热橡胶受到广泛关注,并取得了可观的研究成果。随着现代科技的发展,人们对导热橡胶性能、制备、多样性等提出了更多苛刻的要求。本课题首先探究了交联密度对天然橡胶热导率的影响,通过改变助剂的用量,控制橡胶的交联密度和热导率。研究发现分子链的紧密度和活动能力共同影响着天然橡胶的热导率,两方面相互制约,又共同对热导率的提高有促进作用,较低温度时分子链运动性能起主导作用,较高温度时分子链紧密度起主导作用。然后采用不同的共混工艺制备碳纳米管填充天然橡胶复合材料,研究碳纳米管对天然橡胶导热性能的影响。研究表明：在机械共混中,随碳纳米管用量的增加,天然橡胶热导率稳步上升,填充份数为12vo1%时,热导率随温度在0.224W/(m·K)到0.242W/(m·K)之间变化。天然胶的拉伸强度随着碳纳米管填充量的增加先上升后下降,在6vol%时达到最大值,拉断伸长率不断下降。管长越长、管径越大的普通碳纳米管对天然橡胶的导热和机械补强作用更加明显,而A-MWNT能明显提高天然橡胶的热导率,但机械补强作用非常差。通过溶液共混工艺将磁化碳纳米管填充到天然橡胶中,在磁场作用下制备磁定向碳纳米管天然橡胶复合材料。磁化碳纳米管的包覆率越大,在磁场中受到的力越大,定向越彻底,复合材料热导率越高。碳纳米管用量的增加有助于提高橡胶热导率,当用量超过8vol%时,橡胶热导率上升迅速。较大的磁场强度有助于提高磁化碳纳米管的顺磁定向,提高材料热导率,但当磁场过大时,磁化碳纳米管受到磁场吸引发生移动造成分布不均现象,会降低热导率。磁场角度越接近热导率检测角度,天然橡胶热导率越大,当磁场与检测方向垂直时,热导率最小,且当磁场与检测方向角度大于45°时,热导率小于未定向的碳纳米管天然橡胶复合材料。
[Abstract]:In recent years, thermal conductive rubber has received extensive attention, and has made considerable research results. With the development of modern science and technology, the properties and preparation of thermal conductive rubber have been studied. In this paper, the influence of crosslinking density on the thermal conductivity of natural rubber was investigated, and the amount of additives was changed. It is found that the density and activity of molecular chains affect the thermal conductivity of natural rubber together, and both of them restrict each other and promote the increase of thermal conductivity. Molecular chain movement at lower temperature and molecular chain tightness at higher temperature play a leading role. Then carbon nanotube filled natural rubber composites are prepared by different blending processes. The effect of carbon nanotubes on the thermal conductivity of natural rubber was studied. The results showed that the thermal conductivity of natural rubber increased steadily with the increase of carbon nanotube content in mechanical blending, and the filling fraction was 12vo1%. The thermal conductivity varies from 0.224 W / m 路K) to 0.242 W / m 路K). The tensile strength of natural rubber increases first and then decreases with the increase of carbon nanotube filling, and reaches its maximum value at 6vol%, and the elongation at break decreases continuously. The longer the tube is, the longer the length of the tube is. The larger the diameter of carbon nanotubes, the more obvious the thermal conductivity and mechanical reinforcement of natural rubber, while A-MWNT can significantly improve the thermal conductivity of natural rubber. But the mechanical reinforcement is very poor. Magnetized carbon nanotubes (MCNTs) are filled into natural rubber by solution blending process, and magnetically oriented CNTs are prepared by magnetic field. The higher the coating rate of magnetized CNTs is, The greater the force in the magnetic field, the more thorough the orientation, the higher the thermal conductivity of the composite. The increase of carbon nanotube content is helpful to increase the thermal conductivity of rubber, when the amount of carbon nanotube is more than 8vol%, The large magnetic field intensity is helpful to improve the paramagnetic orientation of magnetized carbon nanotubes and increase the thermal conductivity of the materials. However, when the magnetic field is too large, the magnetic field attraction of the magnetized carbon nanotubes will lead to the uneven distribution of the magnetized carbon nanotubes. The closer the angle of magnetic field is to the angle of thermal conductivity detection, the greater the thermal conductivity of natural rubber is. When the magnetic field is perpendicular to the direction of detection, the thermal conductivity is the least, and when the angle of magnetic field and detection direction is greater than 45 掳, Carbon nanotube natural rubber composites with thermal conductivity less than undetermined direction.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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