Preparation And Properties Of Natural Rubber And Its Nanocomposites

Natural rubber is a widely used basic material derived from the rubber tree.Due to the differences in planting conditions and processing techniques at home and abroad,natural rubber in the different countries have different properties.Therefore,it is valuable to conduct performance tests and clarify the mechanism between structure and properties of different natural rubber.In the first part of the paper,eight grades of domestic and foreign natural rubber were collected and tested for basic performance.Compared with foreign NR,domestic NR has higher plasticity,but had lower vulcanization crosslinking density,poor physical and mechanical properties,weaker rolling resistance and ozone aging resistance.It is worth mentioning that a certain brand of natural rubber developed by Hainan natural rubber group has the highest mechanical properties,and the ozone aging resistance reaches the same level as that of smoked sheet rubber,indicating that our country has the ability to produce high-performance natural rubber.For the future development direction of domestic natural rubber,efforts should be made to improve mechanical properties and aging resistance,as well as reduce rolling resistance,and realize the industrialization of domestic high-performance natural rubber.There are many non-rubber components in natural rubber.Protein,as a substance that plays the role of linking molecular chains,has influence on the comprehensive properties of natural rubber and its nanocomposites.Therefore,it is necessary to explore the protein mechanism for the development of domestic high-performance natural rubber.In the second part of the paper,the protein content was regulated by physical centrifugation and proteolysis to get natural rubber with different protein contents.The comprehensive performance test of natural rubber raw rubber and silica/natural rubber composites was carried out.It was found that adding 10‰(calculated by dry rubber content)protease to fresh latex can not only shorten the coagulation time and reduce the protein content in rubber,but also show better mechanical strength and lower rolling resistance.Natural rubber raw rubber and silica/natural rubber composites all has the best properties at 10‰ protease in fresh latex.Truck tires are one of the most important applications of rubber nanocomposites,and the improvement of cutting resistance and wear resistance is beneficial to the safety and service life of tires.The common technology to improve wear-resistant and cutting-resistant is to combine with styrene-butadiene rubber but styrene-butadiene rubber mainly relies on the petrochemical industry.Epoxidized natural rubber as a new variety of natural rubber maintains the tensile-induced crystallization and strong adhesion properties,which has potential application value in "green tires".In the third part of the paper,nanocomposites were prepared by combining ENR and NR.First of all,in the form of using solid raw rubber together,the addition of ENR not only maintains the excellent tensile properties of natural rubber,but also improves the wear resistance and cutting resistance of the material with the increase of the ENR fraction.Further,experiments were carried out in the form of liquid latex mixing,and this result was also verified.