| Low temperature fluororubber not only has excellent heat resistance,but also has excellent low temperature resistance than ordinary fluororubber.In this paper,the basic structure of four kinds of low temperature fluororubber was compared,and the brittleness temperature,shrinkage temperature and other basic mechanical properties of four kinds of fluororubber were studied.A kind of low-temperature fluororubber was selected as the matrix to study the effects of reinforcing filling system,curing system and acid absorbent system on the properties of low-temperature fluororubber.The pyrolysis carbon black of waste tire was used as reinforcement filling system in low temperature fluororubber,and compared with N990,the reinforcement performance of pyrolysis carbon black of waste tire on low temperature fluororubber was studied.Three methods were used to modify pyrolysis carbon black of waste tire to improve the reinforcement performance of low temperature fluororubber.The results show that:The main structures of CG-FLT,Viton 600s,PL855 and VPL85540 were determined by FTIR.CG-FLT,Viton 600s and PL855 are metafluoroether fluoroelastomers with similar structure.The structural units are vinylidene fluoride,tetrafluoroethylene,perfluoromethyl vinyl ether and vulcanization point monomer.Vpl85540 is composed of vinylidene fluoride,tetrafluoroethylene,perfluoromethyl vinyl ether,perfluoromethylene vinyl ether and vulcanization point monomer.The glass transition temperatures of CG-FLT,Viton 600s and PL855 were-30?.The glass transition temperature of CG-FLT is close to that of PL855.The glass transition temperature of VPL85540 is-40?.Through MSR and ARES-G2 test,the relative molecular weight of four grades of low temperature fluororubber was obtained:PL855>VPL85540>600s>CG-FLT.CG-FLT,Viton 600s and PL855 have the same brittle temperature and temperature retraction TR-10,while VPL85540 has the lowest brittle temperature and temperature retraction TR-10N550 and N330 have higher reinforcement efficiency than N990 with large particle size,and the hardness of fluororubber is improved more obviously with small particle size carbon black.Excellent tensile properties can be obtained by using small and large particle size carbon black together.The addition of reinforcing filler can increase the compression set of low temperature fluororubber,and the increase of compression set is more obvious with small particle size carbon black.The amount and particle size of reinforcing filler have no effect on the low temperature shrinkage of TR-10.The crosslinking efficiency of DCP was lower than that of DBPH,and the tensile properties and compression set of DCP were worse than that of DBPH.Zn O is superior to Mg O/Ca(OH)2 in all properties,so Zn O is preferred in low temperature fluororubber.CBp has a great influence on the vulcanization characteristics of fluororubber:the degree of chemical and physical crosslinking network of fluororubber reinforced by CBp is higher than that of N990,and CBp has a strong effect on delaying the vulcanization rate of fluororubber.The tensile modulus and hardness of CBp reinforced fluororubber were higher than that of N990,but the tensile strength was lower than that of N990.CBp reinforced fluororubber has higher compression set and brittleness temperature than N990.Different methods of modifying CBp have different effects on its reinforcement performance.The results show that the modified effect of supercritical fluid combined with CBp/CNT hybrid particles is the best,and the tensile properties of CBp reinforced fluororubber are greatly improved on the basis of no obvious influence on vulcanization characteristics,compression set and brittleness temperature. |
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