Study On The Dispersion Of Carbon In Natural Rubber And The Properties Of Its Rubber

This paper comes from Double Coin Holding LTD,China.The dispersion of carbon black(CB)has a great influence on the mixing quality and extrusion calendering process of rubber.In this study,the effects of different characteristics of CB on the dispersion of natural rubber were studied,which provided theoretical and experimental supports for the formulation of reasonable technical standards for CB purchasing and the improvement of extrusion calendering process in factories.In this paper,the structuredness and particle size of CB were characterized by particle size measurement,nitrogen adsorption(NSA),iodine adsorption,oil absorption(DBP),compression oil absorption(compressed DBP)and color strength method.Then,in the standard formula and practical formula,with the help of conventional mechanical properties,dynamic mechanical analysis(DMA,RPA),CB dispersion and other modern analytical testing methods were used to study the accumulation and dispersion behavior of CB in the natural rubber and mechanical properties of the compound.The results show,for No.3 CB,the CB dispersive effect is better with the increase of CB structuredness due to the better combination between CB and rubber.With the increase of CB structuredness,the tensile strength and the elongation at break increase of vulcanized rubbers,but their tearing force and the flexural property decrease,and the compressive heat is higher.For No.2 and No.1 CBs,Payne effect is more obvious with the increase of CB structuredness and the CB dispersive effect is worse with the increase of binder content.With the increase of CB structuredness,the tensile strength and the tearing force of vulcanized rubber increase,but the elongation at break decrease.The flexural property is better before aging but worse after aging.For N330 with large-size particle(?2 ?m)of CB,the large-size particle is still in the binder after dispersion process,the results of which are that the stretching strength,the elongation at break and flexural property of vulcanized rubbers decrease,respectively.For the compound rubber with different diameter N234,the dispersive effect of the small particle-size CB is worse.Corresponding,Payne effect is more obvious and the compressive heat is worse.The heat of vulcanized rubbers is higher and wet traction is worse.The tearing force and the elongation at break of vulcanized rubbers increase before aging,but their tearing force decreases and the elongation at break increases after aging,respectively.