| Nitrile rubber (NBR) has excellent oil resistance, a non-polar solvent resistance and antistatic properties. Chloroprene rubber (CR) has good mechanical properties and good self-reinforcing, they are both polar rubber, if NBR blends with CR, the blends can obtain good resistance to aging and oil properties. In this paper, a series of studies on NBR/CR blends has been investigated and the main purpose is to provide a reference for its industrial application.(1) The NBR/CR mixing rubber and vulcanized rubber were studied by differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA). The experimental results showed that NBR and CR had some interaction with each other, and their Tg were close to each other after blending. The storage modulus (E’) in the range of temperature from20℃to60℃maintained for a longer platform, this result indicated that the vulcanizates have relatively effective crosslinking and perfect crosslinked network.(2)Composite vulcanization systems were applied in NBR/CR blends. The physical properties of the NBR/CR blends showed that mooney viscosity and curing rate declined, the tensile strengths modulus at100%and modulus at200%and thermal aging property were improved with the decrease of NBR/CR ratio, but oil resistance was decreased. First blending NBR and CR feeding their own Vulcanizing agent respectively and put the two mixed rubber together, using this mixing method, the results were showed as follows:the vulcanizing agent of NBR/CR blends has almost non-existent migration phenomenon. The vulcanizates have higher crosslinking degree and good mechanical properties and aging properties, Through RPA dynamic mechanical properties of scanning test found that the dynamic performance of vulcanized rubber for the dependence of the strain was larger by this mixing method.(3) With the consideration of difference in curing system between the two rubbers, We studied the influences of different vulcanization systems on the NBR/CR blending rubber. And through each phase of the crosslink density to characterize the speed of each phase.The results showed in NBR different vulcanization systems, the blends were cured by general sulphur vulcanization system possessed better mechanical property and they had similar vulcanization rate. Different curing system in the CR, the metal oxide vulcanization system with other vulcanization accelerator were applied in NBR/CR blends, its liquidity and aging resistance of the rubber was better than that of sulfur vulcanization system, but the sulfur vulcanization system had the maximum crosslink density and good resistance to swelling properties. the metal oxide vulcanization system with TT made the two phase vulcanization rate was relatively large, resulting in the mechanical properties was lower than the other vulcanization system. The uniform design method was applied to investigate the effect of two curing agent system on the properties of blends. The results showed that the properties of blends perform well when the S dosage of1.4to2.5phr and NA-22dosage of0.14～0.6phr.Studied on the influence degree of NBR and CR vulcanization system respectively, we found that NBR sulfur vulcanization system on the properties of NBR/CR blend influence significantly greater than CR metal oxide/thiourea curing system by analyzing physical properties and the RPA test.(4) In the peroxide system research, we found the best amount of DCP and the TAIC ranges from2.4to3.4and2.6～3.6respectively. With the increase of DBPH, the mechanical properties of blends were declined, the dosage should not exceed3.5.(5) The influences of phenolic resin206、PN160、VPN1132on the NBR/CR blending rubber were studied. The research represented that in the nor carbon black blending rubber, the three resins can enhance the blending rubber the mechanical properties. but decrease curing rate. At the same dosage, the206resin had better reinforcing effect. The properties of blends perform well when the dosages of three kind of resins are10～20,10～20,10～15phr, respectively. The influence of content of N550carbon black on the properties of NBR/CR blend was investigated. The results indicated that the content of N550carbon black influence on the dynamic properties, processability, the curing characteristic, and the mechanical properties of NBR/CR blends. The more loading in compound, the more obvious Payne effect appeared. When the N550dosage was60phr, the NBR/CR blend had optimum properties.(6) The carbon black with resin composite reinforcing system filled NBR/CR blend were investigated, the results showed that the curing characteristic、the mechanical properties and the dynamic properties of NBR/CR blends were great changes in the case of maintain the total amount with resin206instead of part of the carbon black. The blend had the optimal mechanical properties when both with a total of80phr and when resin206instead of10phr carbon black, the carbon black and resins have the best synergy. |
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