| As we all know, the gas permeation rate of the vast majority of rubbers are high due to their bad gas tightness apart from the butyl rubber, who is exceedingly applicable to tyre domain benefited from its advantage of excellent gas barrier property. The quantity of the butyl rubber demanded in our country is tremendous, especially in tyre industry, in which the butyl rubber is used to be the gas impervious liner and the inside liner of the tyre. However, it is a regret to note that the production capacity of the butyl rubber in our country is far from enough to meet the demand. In order to solve the problem mentioned above, a new micro-nano laminated barrier material, namely MLBM, is proposed to replace the butyl rubber in this paper. The excellent property of the MLBM makes itself to be the main raw material of the gas impervious liner and tire inner liner. And then, the price of the butyl rubber is decreased and the monopoly of foreign is broken. The main work content and the research results of this paper are as follows:1. The mould internal laminated co-extrusion device is designed and manufactured to prepare the MLBM based on the nano laminated composite technology, and the device is debugged successfully. The extrusion effect and the laminated effect of the device are verified by the plastic-plastic co-extrusion and the plastic-rubber co-extrusion. The viscous encapsulation phenomenon and the interfacial instability phenomenon during the experiment process are analyzed using the polymer theology theory. And then, the finished MLBM, whose thickness is uniform, is obtained with carefully selected raw materials, accurate controlled processing parameters and properly designed flow structure.2. The co-extrusion flow phenomenon of different kinds of the materials is analyzed by using the POLYFLOW software. The effects of the entrance volume flow rate, the material viscosity and the co-extrusion temperature are researched. The results show that the position of the co-extrusion interface is decided by the entrance volume flow rate and the material viscosity, while the effect of the co-extrusion temperature could be ignored. In the condition of the same material viscosity, the co-extrusion interface will move to the side, whose entrance volume flow rate is smaller and the movement will be bigger as the entrance volume flow rate ratio increase. In the condition of the same entrance volume flow rate, the co-extrusion interface will move to the side, whose material viscosity is smaller and the movement will be bigger as the material viscosity difference increase. The simulation results are verified by the experimental results, which has a significance influence on the producing of the MLBM.3. Based on the results of model analysis, the MLBM is prepared using the mould internal laminated co-extrusion device, and the microstructure characteristics, the tensile strength and the gas barrier property of the MLBM are tested. The results show that the gas barrier property of three kinds of barrier materials prepared by the device is better than the pure EPDM. The oxygen transmissibility of the (PA6+EPDM-g-MAH+EPDM)/EPDM is decreased as the PA content increase, while the tensile strength is increased at first and then decreased. The oxygen transmissibility of the PA6/EPDM-g-MAH/EPDM is also decreased with the increasing of the PA content and the tensile strength is increased. The minimum osmotic coefficient of the barrier material prepared by the mould laminated co-extrusion device can reach to 3.603×10-13cm3·cm/(cm2·s·Pa), which is 33.93% of the pure EPDM’s and is much less than that of the appropriative rubber compound used for tyre liner.In this paper, the mould internal laminated co-extrusion device is developed successfully and the rubber compound owning the excellent gas barrier property is prepared with the guide of the model analysis. Beyond that, the forming process of the device is optimized based on the analysis and experimental results. |
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