Studies On The Effect Of Temperature On The Properties Of Rubber Materials And Its Mechanism

The effect of temperature on mechanical properties and dynamic mechanical properties of natural rubber(NR)and fluoro rubber(FKM)are studied in this paper.We mainly investigated the influence of vulcanization system,reinforcing filling system,rubber type and protection system on the properties of NR and FKM at different temperatures.The mechanical properties,dynamic mechanical properties and thermal stability of NR and FKM were measured by high temperature tensile machine,the dynamic thermal mechanical analyzer(DMA)and thermo-gravimetric analyzer(TGA)respectively.Firstly,the effects of vulcanization system,reinforcing the filling system and protection system on the resistance to high temperature of NR were studied in this paper.We mainly examined the inflences of vulcanization system which included conventional vulcanization(CV),semi-effective vulcanization(SEV),effective vulcanization(EV)and two kinds of peroxide vulcanization(DCP1 and DCP2),the amount of carbon black and the kinds of antiagers on the resistance to high temperature of NR.The results showed that with the temperature rising,the stress-strain curve of NR with different vulcanization systems fell,the matrix enhanced function of carbon black particles for rubber gradually weakened.Tensile strength of NR added different stabilizers decreases gradually,while the elongation at break as a whole increased gradually with the temperature rising.Besides,the effects of raw rubber types,vulcanization system and reinforcing the filling system on the resistance to high temperature of FKM were studied in this paper.We mainly examined the effects of raw rubber types(FKM2603,FKM 2462 and FKM 246G),vulcanizing system(the ratio of bisphenol AF/BPP)and reinforcing the filling system(the amount of carbon black and BaSO4)on the resistance to high temperature of FKM.The results showed that the resistance to high temperature of FKM was better with the fluoride being larger at the same temperature.When the amount of BPP was 0.4phr,the resistance to high temperature of FKM increased with the increasing of bisphenol AF.When the amount of bisphenol AF was a constant,the bigger was the amount of BPP,the better was the resistance to high temperature of FKM.With the increasing of temperature,the stress-strain curve of FKM with different amounts carbon black became short.The reinforcing effect of carbon black was better than BaSO4 for FKM.The data of DMA showed that at 125 degree the order of storage modulus of NR with different vulcanization system: SEV>CV>DCP1>EV?DCP2.The addation of antiagers was no significant difference to storage modulus of NR.FKM that had larger fluoride had higher storage modulus at the same temperature.When the amount of BPP was 0.4phr,the storage modulus of FKM increased with the increasing of bisphenol AF.When the temperature rose,the internal network of carbon black in NR and FKM was destroyed by thermal motion,so the contribution of carbon black network to storage modulus was disappeared.The data of TGA displayed that vulcanization system and protection system had a little effect on the thermal stability of the NR and FKM.The thermal stability of FKM246 G was better than FKM2603 and FKM2462.With the increase of amount of carbon black,the thermal stability of the NR and FKM gradually improved.Molecular inter-atomic forces FKM decreased faster than that of NR with the increase of temperature,and the retention rate of mechanical properties of NR was far higher than that of FKM.