Carbon Nanotube Dispersion And Carbon Nanotube/natural Rubber Research On Wet Blending Process

Rubber products are widely used in defense and military industries,agriculture,transportation and daily life.To enhance the physical properties of rubber such as mechanics and wear resistance,nano-filler reinforcement is usually added,followed by compounding and vulcanization processes to obtain practical rubber products that meet the performance requirements.With its excellent mechanical,thermal and electrical properties,carbon nanotubes are attracting the attention and favor of researchers.Compared with the traditional dry(mechanical)mixing process,the wet mixing process has many advantages,such as energy saving,low carbon and environmental protection,clean and hygienic,and the uniform dispersion of fillers to improve the performance of rubber products,which has become the focus of rubber scientists.However,in order to improve the dispersion effect of nano-fillers,mechanical stirring,ultrasonic dispersion and sanding,grinding and other technical means are mainly used.Ultrasonic dispersion and mechanical stirring have low processing capacity and cannot realize large-scale production,sanding and grinding technologies can improve the dispersion effect of nano-fillers,but the particle structure of nano-materials after grinding is destroyed,which has a negative impact on the performance of the material itself and thus cannot guarantee the final performance of rubber products.Based on this,this project adopts numerical simulation,theoretical analysis and experimental research to develop carbon nanotube airflow conveying jet dispersion and carbon nanotube-natural rubber wet mixing equipment,explore and study the carbon nanotube dispersion and carbon nanotube-natural rubber wet mixing process and the performance of the compounding rubber,the main work done and the conclusions obtained are as follows:(1)The airflow transport jet dispersion of carbon nanotubes under different nozzle types was simulated with the help of Comsol numerical simulation software,and the results showed that the asymptotic nozzle was the best for obtaining better dispersion distribution of carbon nanotubes in large space.After that,a carbon nanotube airflow transport test platform was built and the effect of nozzle length on the dispersion effect of carbon nanotube airflow transport jets was investigated.The results show that the dispersion diameter of carbon nanotubes decreases with increasing the length of the expanding nozzle,and the relationship between the two is approximately quadratic;under the condition of fixed nozzle length,the dispersion diameter increases with increasing the jet height,and the fitted curve follows a linear distribution;increasing the jet speed increases the dispersion diameter of carbon nanotubes,and the two are positively correlated.(2)The laser particle size measurement and SEM analysis show that the developed mechanical stirring mixing and dispersing equipment is more helpful to improve the dispersion of carbon nanotubes than the conventional stirring and dispersing equipment in the laboratory,and the carbon nanotube agglomerates are dispersed into smaller agglomerate particles with more uniform particle size distribution.(3)The study on the vulcanization characteristics showed that,under the same vulcanization conditions,the developed carbon nanotube mechanical stirring mixing and dispersing equipment yielded a compound with higher crosslink density after vulcanization compared to the conventional laboratory mixing and dispersing equipment,but there was no significant difference in the scorch time t10 and the positive vulcanization time t90 was also smaller.The tests on dynamic mechanical properties showed that ?G’ was lower and the Payne effect was smaller for the blends made with the carbon nanotube mechanical mixing and dispersing equipment at the same speed.In summary,through the development of carbon nanotube air jet dispersion equipment and mechanical stirring mixing and dispersing equipment,we have explored and studied the carbon nanotube dispersion and carbon nanotube-natural rubber wet blending process and the performance of the blended rubber,and verified the advantages of the carbon nanotube/natural rubber mechanical stirring mixing and wet blending equipment in improving the carbon nanotube dispersion effect,which provides theoretical support and technical support for the large-scale industrial production of carbon nanotube/natural rubber wet blending.It provides theoretical support and technical guidance for the large-scale industrial production of carbon nanotube/natural rubber wet mixing.