Preparation And Properties Of High Performance Elastomer Based On Methyl Methacrylate Grafted Natural Rubber

Methyl methacrylate grafted natural rubber(MGNR)is the only commercial material in the grafting filed of natural rubber(NR).The modulus,abrasion resistance and solvent resistance of MGNR is superior to NR for because of methyl methacrylate side chains.The early research about MGNR mainly focuses on the preparation,also there are few reports on the application of MGNR.In order to extend the application of MGNR,this dissertation studied the effect of sulfurization system,amount and type of carbon black(CB)on MGNR's structures and properties.Based on this,the influence of rubber proportion,CB or Silica dosage on the structure and properties of NR/MGNR composite were explored,all the above works were aimed to obtain an elastomer high performance based on MGNR.The specific works are as follows:Firstly,peroxide vulcanization system,conventional sulfur vulcanization system and semi-efficient sulfur vulcanization system were utilized to explore the effect of vulcanization system on the processing properties,crosslinking density,mechanical properties,mullins effect and abrasion-resisting performance of the vulcanized rubber,the results illustrated that MGNR cured by semi-efficient sulfur vulcanization system had the best comprehensive performance,whose tensile strength and 100% tensile strength were 20.96 MPa and 8.80 MPa,repectively.When the amount of CB was 20 phr,the tensile strength of MGNR was 23.34 MPa,which was 11.35% higher than that of MGNR without CB.When the amount of CB was 50 phr,the mooney viscosity ML(1+4)120? of MGNR was up to 110.24 and the burnt time was 2.17 min,which was not suitable for the preparation of complex or thicker products.Compared with N330,N660 and N770,MGNR filled with N330 showed the maximum tensile strength.And also the mullins effect and the abrasion-resisting performance was the best.In order to improve the processing properties of MGNR or MGNR/CB composites,and enhance the mechanical properties of MGNR/CB further,NR was added to MGNR and then the dissertation studied the structure and properties of the composite materials.The results demonstrated that the processing and mechanical properties of NR/MGNR composite were higher than that of MGNR after adding NR.The mooney viscosity ML(1+4)100? of NR/MGNR(70/30)composite was 23.19,which was 30.56% lower than that of MGNR.The tensile strength of NR/MGNR(70/30)composite was 28.04 MPa,which was 33.78% higher than that of MGNR.After adding 20 phr CB,the tensile strength of NR/MGNR(70/30)composite was 33.09 MPa,which was 18.1% higher than that without CB.After adding 50 phr CB,the Mooney viscosity ML(1+4)100? of NR/MGNR(70/30)composite was 36.59,compared with the MGNR/CB ML(1+4)120?(110.24)reducing sharply.The introduction of NR improved the processing performance of MGNR/CB composites and the amount of carbon black that could be filled.After adding 10 phr Silica,the tensile strength of NR/MGNR(50/50)composite was 31.19 MPa and elongation at break was 605%.Which were increased by 42.36% and 28.98%,respectively,compared with the composite unfilled with Silica.Through the analysis of tensile section,Silica enhances the compatibility between NR and MGNR,and thus effected the mechanical properties of the composites.Elastomers with excellent performance(tensile strength 31.19 MPa,elongation at break 605%)with low Silica filling(10phr)were prepared.