Wet Mixing Mechanism And Experimental Study Of Carbon Black Natural Latex Based On Atomization Process

Mixing is the first and the most important process in the production of rubber products.The quality of mixing rubber not only affects the subsequent processing,but also,and more importantly,the performance and life of rubber products.The mixing process consumes about 50% of the energy consumption of the entire production of rubber products,so the study of rubber mixing methods is of great significance to the development of the rubber industry and the study of "carbon neutrality" in the production of rubber products.Traditional dry mixing technology,the process of preparing rubber blends is tedious and causes dust pollution to the environment.At present,wet mixing technology has the advantages of increasing the number of filler parts in rubber formulations,improving the dispersion of fillers in rubber composites,reducing dust pollution of fillers in the mixing process and reducing energy losses,but the hydrophobicity of carbon black restricts its dispersion in natural latex,resulting in its reinforcement effect cannot be fully developed,so the study of wet mixing technology to prepare green highperformance Therefore,it is an urgent problem to study how to prepare green and high performance rubber composites by wet mixing technology.In this paper,a dual atomization flocculation method of carbon black/natural latex was proposed;the reinforcement mechanism and pretreatment process of carbon black and natural latex were investigated;the effects of the addition of potassium oleate,different types of carbon black,different grinding times of carbon black and the amount of carbon black on the overall performance of rubber composites were studied;highquality blended rubber was prepared.The main work accomplished in this paper is as follows:(1)A double atomization flocculation method for the preparation of wet masterbatch of carbon black/natural latex system was proposed,and the flocculation mechanism was investigated.The process of achieving flocculation of carbon black and natural latex in air under the action of collision force and shear force was analyzed;the interactions between carbon black and natural latex and the intrinsic connection between carbon black and natural latex macromolecular chain reinforcement of natural latex were explored.The method solves the problems of poor dispersion performance of carbon black in rubber composites in the traditional stirring flocculation method,and chemical reagents affecting the mechanical properties of rubber products and causing environmental pollution in the acid addition flocculation method.(2)The method of potassium oleate(anionic surfactant)modification of natural rubber latex was proposed,and the reaction mechanism was studied.The reaction process between potassium oleate and natural latex was analyzed,and the chemical reaction between the carboxyl group in potassium oleate and the amino group in the protein on the surface of natural latex particles and the chemical cross-linking between them were investigated.This method can destroy the outermost protective layer of latex particles,increase the contact area between carbon black and rubber macromolecules,and help improve the dispersion performance of carbon black in the rubber matrix.(3)A dual atomization flocculation preparation of carbon black/natural latex system wet masterbatch blending process technology was developed.The intrinsic law of the effect of the change of formulation and process parameters on the rubber performance was investigated,and the best formulation system and process parameters for the wet blending of carbon black/natural latex were explored.This process can not only improve the dispersion of carbon black in the wet mixing masterbatch,but also realize the efficient dehydration and rapid drying of the wet masterbatch,which solves the problems of poor dispersion of carbon black in the rubber matrix and poor aging resistance of rubber due to long time high temperature drying of the gel.(4)Experiments on the preparation of carbon black/natural latex wet masterbatch blends were carried out by the self-developed dual atomization flocculation test platform,focusing on the effects of the variation of formulation and process parameters on the properties of rubber composites.(1)The effect of the number of potassium oleate parts on the properties of rubber composites was investigated.The experimental results showed that when 1.5 phr potassium oleate was added,the overall performance of the prepared rubber composites was the best.(2)The effect of carbon black type on the properties of rubber composites was investigated.The experimental results showed that the best overall performance of the rubber composites prepared by using carbon black N115.The tensile strength increased by 4.24%,the tear strength increased by 6.18%,and the DIN wear volume decreased by3.31% under the same conditions by this method compared with the stirred flocculation process.(3)The effect of carbon black grinding time on the rubber composite properties was investigated.The experimental results showed that the rubber composites prepared by grinding time of 2 h had the best overall mechanical properties.Among them,tensile strength: 14.97% compared with 1 h grinding and 17.95% compared with 3 h grinding;tear strength: 32.52% compared with 1 h grinding and 36.98% compared with 3 h grinding;DIN wear volume: 2.72% compared with 1h grinding and 22.04% compared with 3h grinding.(4)The effect of the flow rate of the material atomized by the gun on the properties of the rubber composite was investigated.The experimental results showed that the best overall mechanical properties of the prepared rubber composites were obtained at a flow rate of 200 ml/min of the material atomized by the gun.(5)The effect of the number of carbon black parts on the properties of rubber composites was investigated.The experimental results showed that the rubber composites prepared by adding 65 phr carbon black had the best overall mechanical properties.Among them,the tensile strength of the rubber composites was 27.35 MPa,the tear strength was 101.38 MPa,and the DIN abrasion volume was 0.1297 cm3.In summary,the carbon black/rubber wet blending technology based on atomized flocculation process not only enhances the dispersion effect of carbon black in rubber composites,but also improves the overall performance of rubber composites and the filling fraction of carbon black filler,which provides theoretical and experimental data to support the industrialization of carbon black/rubber wet blending technology.