NR has considerable tensile strength and tear strength. The unreinforced vulcanizate NR can reach 17~25MPa, the reinforcement can reach 25~35MPa, the tear strength can reach 98kJ/m, and it does not change with temperature. So remarkable. In particular, the unvulcanized rubber has a much higher tensile strength (green strength) than synthetic rubber. The strength of the unvulcanized rubber is important for processing. If the tire is molded to be subjected to relatively large stretch, if it is broken, the process is difficult to implement. The reason for the NR Green strength enthalpy is that it has good tensile crystallinity on the one hand, and it may contain a gel, especially a tight gel, on the other hand.