Study On Structural Performanceand Blending Process Of CM/XNBR

In this paper, a series of studies on CM/XNBR blends has been investigated. Theperformance variation of blends has been studied under conventional conditions andthe hot oil and hot air aging.The main purpose is to provide a reference for itsindustrial application.(1)The compatibility of CM and XNBR were studied by three-dimensionalsolubility parameter group contribution method, differential scanning calorimetry(DSC), analysis ofthe physical and mechanical properties of blends. The resultsshowed that:CM and XNBR had good compatibility. With the decrease of the twophase proportion difference, compatibility was improved. Blending temperature had animpact on the compatibility of two-phase of blends. At60℃, the compatibility wasbest. Blending time had less impact on the compatibility.(2)The blending ratio of CM and XNBR were studied. The influence of blendratio on the performance of blends before and after aging had been studied in peroxidecuring system and separate curing system.The results showed that it was more suitablefor research when the ratio of CM/XNBR blends was60/40. It can be found that Tworubber should have a good interface strength through the comparison of oil resistanceof blends.(3)The performance of blends with different types and amount of curing systemwere studied when the ratio of CM/XNBR was60/40. The effect of the amount ofDCP, DPBH and BIPB on the performance of blends were studied and compared.Uniform design method was used to study the impact of the PT75/903system ofblends. The results showed that the performance of blends was best when PT75was1.3phr and903was0.7phr. The amount of ZnO had an effect on the system. It cansignificantly accelerate the curing speed and slightly improving mechanical properties. (4)The performance of blends with different blending process were studied whenthe ratio of CM/XNBR was60/40. The results showed that with the DCP/TAIC curingsystem, blending process had an effect on the two-phase crosslinking density, curingcharacteristics and mechanical properties of blends. Conditioning time had an obviousinfluence on the performance of vulcanized rubber at the early stage.Through thecomparsion of three-dimensional solubility parameter of the formulation components,curing system has migration trend to XNBR phase in mixing and conditioning process.With the PT75/903curing system, blending process had small effect on the curingcharacteristics, modulus and mechanical properties of blends. At the small deformation,the modulus of XNBR changed fast, and the modulus of CM changed slow. The trendof modulus of blends was between two pure gum. Loss modulus of blends increasedand then decreased. Loss factor was increased. Loss modulus and loss factor of blendswere significantly higher than two pure gums. Loss modulus of CM and XNBR hadlarge difference.(5)The effect of heat treatment on the performance of blends were studied.Examines the relationship of the two-phase modulus and crosslinking density andmechanical properties of blends. With the decrease of the heat treatment time of CMphase and the increase of the heat treatment time of XNBR phase, the curingcharacteristics of different groups were different. The crosslinking density of CMphare decreased, and the crosslinking density of XNBR phare increased. Thedifference of crosslinking density of two-phare increased. The loss modulus of CMphare increased, and the loss modulus of XNBR phare decreased. The difference ofloss modulus of two-phare increased. Point of intersection of storage modulus of CMand XNBR moved to large deformation. Tensile strength, elongation at break and tearstrength decreased. Modulus at100%, hardness and tension set unchanged.(6)The hot air aging and oil resistance of blends with peroxide curing system werestudied. With hot air aging time increased, the overall crosslinking density and thecrosslinking density of each phase of blends with DCP/TAIC curing system changed.The physical and mechanical properties of blends had small changes after hot air andhot oil aging. With hot air aging time increased, the overall crosslinking density ofblends with DPBH/TAIC curing system increased and then decreased. The physicaland mechanical properties of blends had small changes after hot air and hot oil aging.The results showed that the system had excellent heat aging and oil resistance. (7)The practical formula of CM/XNBR were studied. The effects of three curingsystems of CM and the amount of CM on the performance of blends were studied andcompared with NBR. The results showed that three curing systems of CM had littleeffect on the performance of blends Most of the performance of blends were higherthan NBR or same as NBR. It was also found that when the amount of CM were lessthan30phr, it could not only control costs but also slightly improve some performance,and the performance of blends also can be comparable to NBR. CM/XNBR can beapplied to grease-proof and wear-resisting hose or seal product.