废旧橡胶粉与弹性体复合增韧托辊用PA6聚合物基耐磨复合材料的应用研究

发布时间：2018-10-25 21:01

【摘要】：托辊在带式运输机中有着“心脏”之称。目前市面上已有的托辊材料在使用的过程中都存在诸多问题,如陶瓷托辊过重、脆性大;金属托辊则耐磨性不佳,长时间运转易产生毛刺,而产生的毛刺非常容易降低传送带的使用寿命等;塑料材质托辊的力学性能较差。这些因素限制了托辊的推广应用。本文在实验组前期实验的基础上,选取了聚酰胺6(PA6)作为基体材料,采用POE-g-MAH作为主增韧剂,废旧橡胶粉作为副增韧剂对PA6复合材料进行改性,对实验设计、机理分析、性能检测等进行了相关研究。主要工作如下:首先,采用不同目数(40目、60目、80目)废旧橡胶粉对PA6复合材料进行改性,实验发现:当添加的废旧橡胶粉含量增加到5%的时候,PA6复合材料的冲击强度达到最大值,其中添加40目、60目、80目废旧橡胶粉的复合材料其冲强度分别增加了约20.5%、40.9%、53.8%;断裂伸长率分别增加了约56%、64%、84%;废旧橡胶粉的加入,使得复合体系的粘度、熔点、结晶温度、热稳定性出现了下降的现象。由于废旧橡胶粉对体系的增韧程度有限。采用马来酸酐接枝改性后的POE复合废旧橡胶粉对体系进行增韧改性,研究了POE-g-MAH和废旧橡胶粉不同质量比例的性能,通过力学性能分析,确定了二者的最佳比例为POE-g-MAH:废旧橡胶粉=6:4。PA6复合材料体系成分相对比较复杂,为了较好的考察复合增韧剂含量对PA6复合材料性能的影响,利用复合增韧剂的最佳比例对PA6进行改性研究,实验发现:当复合增韧剂含量为10%时,冲击强度由原来的6.3k J/m2增至8.0 k J/m2,增加了约27%;断裂伸长率由原来的22.1%增至33.2%,增加了约50%;拉伸强度则由原来的77.2MPa下降到59.4MPa,下降了约23%;弯曲强度由原来的90.4MPa下降到60.9MPa,下降了约32.6%;DSC,XRD和TGA结果表明,添加复合增韧剂改善PA6的结晶速率,但结晶度,晶体结构的完整性和耐热性降低。最后,利用复合增韧剂对PA6复合材料进行改性研究。当复合增韧剂含量为15%的时候,其拉伸强度从85.6MPa下降至70.2MPa,下降了约17.9%;弯曲强度从130.2MPa下降至90.9MPa,下降了约30.2%;缺口冲击强度从5.1MPa增加至18.1MPa,增加了约2.5倍;断裂伸长率从6.3%增加至19.4%,增加了约2.07倍;DSC和TGA结果表明,复合材料的熔点、热稳定性出现了下降的现象,其结晶温度出现了上升的现象。
[Abstract]:The roller has the name of "heart" in the belt conveyer. At present, there are many problems in the process of using the existing roller materials, such as ceramic roller overweight, brittleness; The wear resistance of metal roller is poor and the burr is easy to be produced in long time operation, and the burr produced is very easy to reduce the service life of conveyer belt, and the mechanical properties of plastic roller are poor. These factors limit the popularization and application of the roller. On the basis of the previous experiment in the experimental group, polyamide 6 (PA6) was selected as the matrix material, POE-g-MAH as the main toughening agent and waste rubber powder as the secondary toughening agent to modify the PA6 composite, and the experimental design was carried out. Mechanism analysis, performance testing and other related studies were carried out. The main work is as follows: firstly, the waste rubber powder (40 mesh, 60 mesh, 80 mesh) is used to modify the PA6 composite material. It is found that the content of waste rubber powder is increased to 5% when the content of waste rubber powder is increased to 5%. The impact strength of PA6 composites reached the maximum value, and the impact strength of the composites with 40 mesh, 60 mesh and 80 mesh waste rubber powder increased about 20.5% 40.9% and 53.8% respectively. The elongation at break increased about 56%, and the addition of waste rubber powder decreased the viscosity, melting point, crystallization temperature and thermal stability of the composite system. The toughening degree of the system is limited because of the waste rubber powder. Maleic anhydride grafted POE composite waste rubber powder was used to toughen and modify the system. The properties of POE-g-MAH and waste rubber powder with different mass ratio were studied, and the mechanical properties were analyzed. The optimum ratio of POE-g-MAH: waste rubber powder = 6:4.PA6 composite system is relatively complex. In order to investigate the effect of the content of compound toughening agent on the properties of PA6 composites, The modification of PA6 was studied by using the optimum proportion of compound toughening agent. It was found that when the content of compound toughening agent was 10, the impact strength increased from 6.3k J/m2 to 8.0 KJ / m2, which increased about 27kg / m2. The elongation at break increased from 22. 1% to 33. 2%, and the tensile strength decreased from the original 77.2MPa to 59. 4 MPa, which decreased by 23%, and the tensile strength decreased from 22. 1% to 33. 2%, and the tensile strength decreased from the original 77.2MPa to 59. 4 MPa. The bending strength decreased from the original 90.4MPa to 60.9 MPA, and the results of XRD and TGA showed that the addition of compound toughening agent improved the crystallization rate of PA6, but the crystallinity, the integrity of crystal structure and the heat resistance of PA6 were decreased. Finally, the composite toughening agent was used to modify PA6 composites. When the content of compound toughener was 15%, the tensile strength decreased from 85.6MPa to 70.2MPa, and the bending strength decreased from 130.2MPa to 90.9MPa, which decreased about 30.2MPa. The notched impact strength increased about 2.5 times from 5.1MPa to 18.1MPa, and the elongation at break increased from 6.3% to 19.4MPA, which increased by 2.07 times. The results of DSC and TGA show that the melting point and thermal stability of the composites decrease and the crystallization temperature increases.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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