| Rubber products are widely used in various fields of production and life.Due to the diversity of rubber product formula system,a wide variety of compounding agents,large differences in properties and different physical and chemical reaction characteristics,there is poor dispersion in the rubber matrix,resulting in large dispersion of product quality and performance and potential safety hazards.At the same time,in the actual production,because many performance tests of rubber products need to carry out destructive tests on the products,and considering the production cost and other factors,the sampling inspection method is usually adopted.Therefore,improving the uniformity of product performance and reducing the defective rate have very important research value for improving the use safety and reducing the production cost.The natural rubber and cis-1,4-polybutadiene rubber commonly used in industrial production were selected as the research matrix,and a new type of compounding agent wet mixing modification method was adopted to study the pure rubber system and the product system with carbon nanotubes(CNTs)and carbon fiber.Through the dispersion analysis of mechanical property test results,scanning electron microscope(SEM)submicroscopic morphology analysis and thermogravimetric(TGA)heat resistance analysis,the effect of wet composite modification on the improvement of comprehensive properties and the uniformity of properties were explored.The main research contents include:(1)Scanning electron microscope(SEM)was used to observe the submicroscopic morphology of NR / BR pure rubber system.The SEM morphology showed that the mixed rubber interface of the wet mixed modification formula system was more blurred,the dispersed phase size was smaller,and the dispersion was more uniform,indicating that the mixture after wet modification reacted more fully in the rubber matrix,had higher adhesion and more uniform dispersion.The test results of vulcanization curve of conventional formula show that the vulcanization performance of wet modified formula system is greatly improved,and the dispersion of vulcanization performance is also significantly reduced.The positive vulcanization time was shortened,and T90 was reduced from 12.47 min to 10.38 min,with a decrease range of 16.76%.The dispersion of T90 test results decreased from 0.038 to 0.029,with a decrease of 24%,indicating that the vulcanization system is more evenly dispersed and the vulcanization effect is better.The vulcanization rate increased significantly from 31.00 min-1 to 32.96 min-1,with an increase of 6.5%,and the dispersion of vulcanization rate decreased from 0.113 to 0.053,with a decrease of 53%,indicating that the vulcanization efficiency was improved and the overall vulcanization performance was significantly improved;The mechanical property test results show that the tensile strength and elongation at break have been significantly improved.The tensile strength increased from 15.39 MPa to 18.43 MPa,with an increase of 20%,and the dispersion decreased from 0.08 to 0.02,with a decrease of 75%.The elongation at break increased from 479% to 517%,with an increase of 8%,and the dispersion decreased from 0.08 to 0.04,with a decrease of 50%;TGA results showed that the initial decomposition temperature and the fastest decomposition temperature of the wet modification system increased significantly,indicating that the thermal decomposition resistance was enhanced;The aging test shows that the tensile strength of the normal mixing of the conventional formula is reduced from 15.39 MPa to 9.49 MPa,a decrease of 38%,while the tensile strength of the wet mixing is reduced from 18.44 MPa to 13.85 MPa,much higher than the 9.49 MPa of the conventional mixing,indicating that the wet mixing makes the antioxidant in the formula more evenly dispersed and has excellent anti-aging performance.(2)Scanning electron microscopy(SEM)was used to analyze the submicroscopic morphology of NR / BR / CNTs composites.The experiments showed that NR / BR / CNTs nanocomposites could be successfully prepared by wet modification.Exploring the vulcanization performance of conventional formula,it is found that the vulcanization performance of wet modified formula system is greatly improved,and the dispersion of vulcanization performance is also significantly reduced.The positive vulcanization time was shortened,and T90 was reduced from 8.94 min to 4.47 min,with a decrease range of 50%.The dispersion of T90 test results decreased from 0.213 to 0.073,with a decrease of 65%,indicating that the vulcanization system is more evenly dispersed and the vulcanization effect is better.The vulcanization rate increased significantly from 39.02 min-1 to 43.08 min-1,with an increase of 10%,and the dispersion of vulcanization rate decreased from 0.246 to 0.021,with a decrease of 91%,indicating that the vulcanization efficiency was improved and the overall vulcanization performance was significantly improved;The results of mechanical properties showed that the tensile strength and elongation at break were improved in varying degrees.The tensile strength increased from 12.78 MPa to 18.33 MPa,with an increase of 43%,and the dispersion decreased from 0.16 to 0.03,with a decrease of 81%.The elongation at break increased from 480% to 616%,with an increase of 28%;TGA results showed that the thermal stability of NR / BR / CNTs nanocomposites was enhanced by wet mixing compared with normal mixing;The thermal aging test shows that the tensile strength of wet mixing after aging is still much higher than that of conventional mixing,indicating that wet mixing makes the antioxidant in the formula disperse more evenly and has excellent anti-aging performance.(3)Scanning electron microscopy(SEM)was used to explore the submicroscopic morphology of NR / BR / carbon fiber composites.The experiments showed that wet modification and mixing made the interface of carbon fiber in rubber matrix fuzzy,the degree of adhesion higher and the dispersion more uniform.The vulcanization performance shows that wet mixing has no obvious effect on the improvement of vulcanization performance and the reduction of dispersion;The comparison results of mechanical properties showed that the tensile strength increased from 14.89 MPa to 17.92 MPa,with an increase of 20%,and the elongation at break changed from 498% to 627%,with an increase of 26%.The thermal aging test shows that the tensile strength of wet mixing after aging is still much higher than that of conventional mixing,indicating that wet mixing makes the antioxidant in the formula disperse more evenly and has excellent anti-aging performance. |
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