Properties and uses of natural rubber

  natural rubber raw rubber in the glass transition temperature of -72 ℃, plastic flow temperature of 130 ℃, the beginning decomposition temperature 200 ℃, intense decomposition temperature 270 ℃. when the vulcanization of natural rubber, its tg rise, viscous flow can not happen again.
elasticity of natural rubber raw rubber and its not too high crosslinking density of vulcanizates flexibility is high. for example, in the range 0-100 ℃, elasticity at between 50-85 ℃, the elastic modulus of steel is only 1 / 3000 up to 1000% elongation, stretching to 350%, after the permanent retracted deformation of only 15%, higher elasticity of natural rubber, after the general rubber butadiene rubber.
the intensity of natural rubber elastic materials, natural rubber raw rubber, rubber compound, vulcanized rubber have higher strength. the tensile strength of vulcanized rubber is not known as green strength, strength of natural rubber up to the green 1.4 ~ 2.5mpa, the appropriate strength for the rubber molding process greene is necessary. tear strength of natural rubber was also higher, up to 98kn / m, the wear resistance are better. high mechanical strength of natural rubber because it is self-reinforcing rubber, when the tension stress direction along the molecular chain will form a crystal orientation.
the electrical properties of natural rubber natural rubber non-polar substances, is a good insulating material. when the natural rubber vulcanization, the result of the introduction of polar factors, such as sulfur, promoting agent, so that the insulation performance.
dielectric properties of natural rubber, natural rubber resistance is a non-polar substances, it is soluble in non-polar solvents and non-polar oil. natural rubber intolerance cyclohexane, gasoline, benzene and other media, not vulcanized rubber dissolved in the medium, the swelling of vulcanized rubber. the polarity of natural rubber is not soluble in acetone, ethanol, less soluble in water, 10% hydrofluoric acid-resistant, 20% hydrochloric acid, sulfuric acid 30%, 50% sodium hydroxide.
the main purpose of natural rubber, natural rubber because of its highly flexible and good insulation, plastic, drain trap, tensile strength and wear characteristics, widely used in industry, agriculture, defense, transportation, transportation, machinery manufacturing , medical and health fields and other aspects of daily life, such as tires for use on transportation; industrial use of the conveyor belt, belts, all kinds of ring; medical gloves, blood transfusion; used in daily life, shoes, raincoats, warm water bags are the main raw material of rubber manufacturing, national defense use of aircraft, artillery, tanks, and even cutting-edge technology in the field of rockets, satellites, spacecraft, space shuttle and so requires a lot of rubber parts