Study Of Solvent Corrosion Resistance Of SBR/NR Blends

The evaluation of the solvent resistance of rubber materials is mainly based on the following aspects.Firstly,the three-dimensional solubility parameters of rubber materials and solvents,according to the principle of similar solubility,rubber materials and solvents with similar three-dimensional solubility parameters can be better swollen.Secondly,the swelling ratio q of SBR/NR with different solvents which reflects the diffusion of solvent molecules into the blends.Finally,the interaction parameters?_HSPand energy difference Ra between rubber material and solvent molecules,both of which take into account the influence of three-dimensional solubility parameters,reflect the level of swelling ability of rubber material.In this study,SBR and NR were used to combine the advantages of both rubbers and to add the excellent elasticity and other mechanical properties of NR while maintaining the wear resistance,self-adhesiveness and processability of SBR.The effects of the ratio of SBR to NR,different sulfur vulcanization systems and different filler systems on the mechanical properties and swelling behavior of the rubber were investigated.Through the study of the ratio of SBR/NR,it can be obtained that the tensile strength,elongation at break and tear strength of SBR/NR blends decreased with the increase of SBR ratio,and the hardness increases slowly,and the mechanical properties were better when the amount of SBR is 75.At each ratio,the solubility ratio q of the used gum decreased with the increase of energy difference Ra,showing an exponential relationship image.The swelling ratio q in the solvent decreases with the increase of the proportion of SBR,and on the contrary,the energy difference Ra increased.The value of the interaction parameter?_HSP was less than 0.5 when the polymer chains show stretching in the solvent,and q gradually decreased with the increase of?_HSP.By exploring the effects of different vulcanization systems and different sulfur vulcanization systems on the vulcanization characteristics and mechanical properties of SBR/NR compound and the effect of sulfur dosage on the diffusion pattern,it was shown that with the increase of sulfur dosage,the tensile strength first increased and then decreased,and the hardness increased.As the amount of sulfur increased,the cross-linked network formed was gradually tightened and the swelling ratio q of the rubber in the three types of solvents decreased.The swelling ratio q,energy difference Ra,and interaction parameter?_HSP of rubber polymers with different crosslinking densities in different kinds of solvents had the same connection with each other,and these connections jointly explained the diffusion law of polymers in solvents.q was inversely related to Ra,and q gradually decreased with increasing Ra.With the gradual increase of?_HSP,q showed a gradually decreasing trend.By studying the effects of different filler systems on the mechanical properties and swelling behavior of SBR/NR blends,it can be obtained that the tensile strength of the blends with the addition of the four fillers had increased to different degrees,among which the trend of increasing tensile strength was more obvious when 0.5 phr and 5 phr are added.The reason for this phenomenon may be due to the structural form and particle size of the fillers.Firstly,the smaller the particle size of the filler.Secondly,the morphological and structural characteristics of the filler particles.Finally,it was the chemical nature of the filler itself.