Study On Processing Technology Of High Performance Natural Rubber

Natural rubber(NR)is a kind of natural high molecular material produced by rubber tree through self-synthesis,which is composed of rubber hydrocarbon and about 5%non-rubber components.The raw rubber products were prepared by coagulation,dehydration and drying of fresh latex.In this process,the processing technology has an important impact on the comprehensive properties of natural rubber.Nowadays,natural rubber is widely used in aerospace,military and other high-end products,and it also puts forward new requirements for the comprehensive performance of natural rubber.However,the overall performance of domestic natural rubber is poor,and high-performance natural rubber almost completely depends on import.Therefore,optimizing natural rubber processing technology,reducing production costs and improving the comprehensive performance of domestic natural rubber are of great significance for China to realize raw material autonomy in the field of high-end natural rubber products.In this project,natural rubber is treated by clot curing process and coupon curing process,and the effects of these two processing processes on the composition,physical and chemical properties,internal structure and comprehensive properties of natural rubber are studied,so as to provide new ideas for the processing and production of high-performance natural rubber in China.The results showed that the curd of fresh latex was cured for 0,7,10 and 15 days.With the increase of curing time,the content of nitrogen and acetone soluble matter in raw rubber decreased gradually,and the content of water soluble matter decreased first and then increased;The results showed that the relative molecular weight of NR increased to a certain extent,the initial plasticity value P0 and Mooney viscosity showed a trend of first increasing and then decreasing,while the plastic retention rate PRI decreased in a certain range.The curing rate of vulcanizate decreased with the increase of curing time;The mechanical properties such as tensile strength and tear strength were increasing,reaching the maximum value of 29.13 MPa and 31.76 k N/m on the 15th day of curing,which significantly improved the mechanical properties of NR;the heat generation performance is gradually improved;There is no obvious change in fatigue property.According to the research results,natural rubber samples with better comprehensive properties were selected for further treatment of 0,7 and 15 days.The content of non-gum components in raw rubber decreased with the increase of coupon curing time;the initial plastic value P₀and Mooney viscosity increased gradually,the plastic retention rate PRI decreased gradually,and the oxygen aging resistance decreased.The tensile strength and tear strength increased with the increase of the curing time;the thermal and fatigue properties were improved.