【作者】 李伟；

【导师】 邹华；

【作者基本信息】 北京化工大学 ， 材料与化工（专业学位）， 2023， 硕士

【摘要】 氟橡胶是一种分子链高度稳定的含氟弹性体材料。由于具备优异的耐高温、耐介质性能,氟橡胶被广泛应用于各种密封场合。近年来氟橡胶的主要的发展方向为耐低温氟橡胶以及高氟含量的特种氟橡胶制品的研发。本文第一部分内容为低温氟橡胶的制备与性能研究,旨在制备一种耐低温、耐油性能优异的氟橡胶复合材料,并尝试不同的低挥发性增塑剂在低温氟橡胶中的应用。本文第二部分内容是全氟醚橡胶材料的制备研究,通过分析国外全氟醚橡胶产品,加工制备出一种高氟元素含量的全氟醚橡胶材料,以期为特种氟橡胶制品的开发提供数据支持。(1)首先选择了国内外两种低温氟橡胶进行对比。发现国外低温氟橡胶FKM-A热分解温度略高于国产低温氟橡胶FKM-B,且拥有较国产低温氟橡胶更低的玻璃化转变温度,因此优先选用国外低温氟橡胶FKM-A制备耐低温、耐油氟橡胶复合材料。当FKM-A氟橡胶的硫化剂选用2,5-二甲基-2,5双-己烷(双2,5),添加量为1.5份时,硫化橡胶的拉伸强度最高,耐油性能最佳。炭黑填料用量增加,FKM-A氟橡胶耐油性能提升,但过多的炭黑会阻碍橡胶低温下的分子链变形,导致橡胶低温脆性温度上升。将20份N990炭黑与10份小粒径N330炭黑并用制备的FKM-A复合材料耐油性能进一步提升,同时具备优异的耐低温性能。(2)针对国产低温氟橡胶FKM-B尝试了不同的低挥发性增塑剂在低温氟橡胶的应用。发现不同增塑剂的加入均会使得FKM-B氟橡胶交联程度与拉伸强度下降。增塑剂选用氟硅油时,FKM-B氟橡胶交联程度与拉伸强度保持率最高,压缩永久变形率最低。填充3份氟硅油作为增塑剂可以改善FKM-B氟橡胶的低温性能,使其脆性温度下降4℃,同时提升其压缩耐寒系数。增塑剂的加入还可以改善氟橡胶的流动性。毛细管挤出测试表明,添加增塑剂后氟橡胶剪切粘度下降,混炼胶挤出物表面也更为平整,可满足氟橡胶不同成型工艺的流动性要求。(3)对六种国外全氟醚橡胶产品进行了剖析,发现全氟醚橡胶产品可不添加填料或使用少量大粒径炭黑作为填料。当不添加任何填料时,使用硫化剂双2,5可以正常硫化全氟醚橡胶,但是全氟醚橡胶拉伸强度不足。当添加少量大粒径炭黑补强后,只添加硫化剂双2,5的全氟醚橡胶无法正常硫化,需配合助交联剂TAIC使用。通过调整二段硫化时间和温度,可以降低全氟醚橡胶交联程度,提升拉断伸长率,制备出满足性能要求的全氟醚橡胶材料。更多还原

【Abstract】 Fluororubber is a kind of fluorinated elastomer material with highly stable molecular chain.Because of its excellent resistance to high temperature and medium,fluororubber is widely used in various sealing situations.In recent years,the main development direction of fluororubber is low temperature resistance fluororubber and special fluororubber products with high fluorine content.The first part of this paper is the preparation and properties of low temperature fluororubber,aiming at preparing a kind of fluororubber composite with excellent low temperature resistance and oil resistance,and trying different low volatile plasticizers in low temperature fluororubber application.The second part of this paper is the study on the preparation of perfluoroelastomer materials.By analyzing foreign perfluoroelastomer products,a perfluoroelastomer material with high fluorine content is processed and prepared,in order to provide data support for the development of special fluororubber products.(1)The Firstly,two kinds of low temperature fluororubber at home and abroad were selected for comparison.It was found that the thermal decomposition temperature of foreign low temperature fluororubber FKM-A was slightly higher than that of domestic low temperature fluororubber FKM-B,and had a lower glass transition temperature than domestic low temperature fluororubber,so it was preferred to use foreign low temperature fluororubber FKM-A to prepare low temperature and oil resistant fluororubber composites.When the vulcanizing agent of FKM-A fluororubber is2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane,adding 1.5 parts,the vulcanized rubber has the highest tensile strength and the best oil resistance.With the increase of the amount of carbon black filler,the oil resistance of FKM-A fluororubber is improved,but too much carbon black will hinder the molecular chain deformation of rubber at low temperature,resulting in the rise of the low temperature brittle temperature of rubber.The oil resistance of FKM-A composite prepared by combining 20 parts of N990 carbon black with 10 parts of small diameter N330 carbon black is further improved,and it also has excellent low temperature resistance.(2)For domestic low temperature fluororubber FKM-B try different low volatile plasticizers in low temperature fluororubber application.It was found that the crosslinking degree and tensile strength of FKM-B fluororubber decreased with the addition of different plasticizers.When fluorine silicone oil was used as plasticizer,the crosslinking degree and tensile strength retention rate of FKM-B fluororubber were the highest,and the compression permanent deformation rate was the lowest.Filling 3 parts of fluorosilicone oil as plasticizer can improve the low temperature performance of FKM-B fluororubber,reduce its brittle temperature by 4℃,and improve its compressive cold resistance coefficient.The addition of plasticizer can also improve the fluidity of fluororubber.The capillary extrusion test showed that the shear viscosity of fluororubber decreased after plasticizer was added,and the surface of the compound extruded was smoother,which could meet the requirements of the fluidity of fluororubber in different molding processes.(3)Six kinds of foreign perfluoroelastomer products were analyzed,and it was found that perfluoroelastomer products did not use filler or a small amount of large particle size carbon black as filler.The vulcanizing agent bis2,5 can vulcanize perfluoroelastomer normally without any filler,but the tensile strength of perfluoroelastomer is insufficient.When a small amount of large particle size carbon black is added for reinforcement,the perfluoroelastomer with vulcanizing agent bif2,5 cannot be vulcanized normally.The chemical is used with the cross-linking agent TAIC.By adjusting the second curing time and temperature,the crosslinking degree of perfluoroelastomer can be reduced and the elongation at break can be increased,and the perfluoroelastomer material meeting the performance requirements can be prepared.更多还原