The Study On Properties Of Rubbers For Extreme Environment

With the development of science and technology,the situation of rubber products using is becoming more and more strict.In order to produce rubber product that can be widely used in extreme environment,meet the needs of industrial production and improve of people’s living standard,we research in the natural rubber(NR)which is in good cold resistance and fluorine rubber(FKM)which can resist high temperature and high pressure to aim at further improving the comprehensive properties of NR and FKM and broadening their range of application.Natural rubber(NR)had excellent high-elasticity and physical-mechanical properties.The NR had a Tg of-72 °C and maintained a high-elastic state.Crystallization was less likely to occur at low temperatures,so NR can resistance the low temperatures.Therefore,we choose NR as the matrix rubber and develop new low temperature resistant rubber formula by adjusting the curing system and plasticizing system.The results show that the effective Vulcanization system can reduce the permanent deformation of rubber.The addition of plasticizer of low temperature A,B and C could effectively reduce the glass transition temperature of natural rubber and low hardness and low temperature test and XRD test prove that natural rubber which adds plasticizer of low temperature is not crystallize in-54 ℃,maintaining high elastic state and ensure the good comprehensive properties of natural rubber which is used in low temperature environment.Eventually it is determine that two formulations of effective vulcanization system/7phr of plasticizer A and efficienive vulcanization system/10 phr plasticizer C both meet the index requirements of physical mechanical properties,low temperature,compression permanent deformation resistance and abrasion resistance.FKM has excellent properties of high temperature resistant,oil resistant and medium resistance characteristics,in order to further improve the comprehensive properties of FKM,tow kinds of one-dimensional fillers CNTs and PTW were selected to investigate the reinforcing properties of these tow types of fillers in this paper.First of all,the reinforcing properties of CNTs and PTW were compared by the rubber processing analyzer RPA2000 test,the tensile properties at room temperature and high temperature,the compression set and so on.Finally,the filler was selected as the reinforcing filler and the optimum filling amount was summed up.Then the effect of carbon black N990,CNTs and PTW to reinforce FKM and silane coupling agent KH550 on the performance of the system were also investigated.Finally,dopamine was chosen to modify PTW to improve the adhesion between PTW and rubber.FKM reinforced by CNTs had stronger tensile strength,stretch stress,tearing strength and hardness,but the compression permanent deformation of the CNTs/FKM system property was poorer,while the PTW/FKM system kept good compression permanent deformation performance.It was found in the RPA strain scan of mixed rubber that CNTS/FKM system had stronger packing network than PTW/FKM system and Payne effect was obvious.We could see from the results of SEM,existing some reunion in the CNTS and the PTW in FKM,PTW being crushed in the mixing process,.At the same time,the PTW has been withdrawn from the FKM matrix,which showed that the interaction between FKM and PTW was poorer,so PTW reinforcement for FKM was not outstanding,.CNTS could fill cracks of FKM,and it could avoid the phenomenons of fracture,pulling out and cracks,which showed that the interaction between PTW and FKM and the effect of reinforcement were better.According to the comprehensive analyses,the best filling number of PTW and CNTs was 6phr.After the addition of silane coupling agent KH550,the mechanical properties of N990 / PTW system at room temperature and high temperature had been greatly improved,showing a strong synergistic effect.The increase rate of mechanical properties of the system which N990/CNTs were used together was great,the mechanical properties was greater than the sum of the two and also showed a better synergistic effect,but the addition of KH550 did not play a coupling role.However,high temperatures(200 ℃)would destroy the network structure,so that the reinforcing effect of FKM in different filled system became worse,However,the high temperature mechanical strength of N990/PTW/FKM system showed significant synergistic effect.When the KH550 was added,the synergistic effect was further enhanced.The N990/PTW system had better compression performance than N990/CNTs.The results of FT-IR,SEM,EDS and TGA showed that dopamine was successfully adhered to the surface of potassium titanate whiskers by oxidative self-polymerization.And as the concentration of dopamine impregnation increased,the content of polydopamine on the surface of potassium titanate whiskers increased.With the increase of dopamine impregnation concentration,the tensile strength and modulus of the modified PTW / FKM composites increased significantly,and the elongation at break decreased,while still maintaining good compression set.At the same temperature,the storage modulus of modified PTW / FKM composites also increased.The surface hydrophilicity of modified PTW / FKM composites increased accordingly.