Chemical properties of (1) black natural rubber. Black natural rubber is an unsaturated rubber, which is prone to vulcanization reaction (structural reaction) with vulcanizing agent, oxidative cracking reaction of bromine with oxygen and ozone, chlorination and chemical reaction with halogen, and chemical reaction with catalyst and acid.
However, because natural rubber is a polymer compound, it has the reaction characteristics of olefinic organic compounds, such as slow reaction speed, incomplete and uneven reaction, and coexistence of various chemical reactions (such as oxidative cracking reaction and structured reaction).
Among all kinds of chemical reactions of natural rubber, the most important ones are oxidative cracking reaction and structural reaction. The former is the theoretical basis of raw rubber plasticizing, and it is also the reason for the aging of folic acid gum. The latter is the theoretical basis of vulcanization of raw rubber. Chlorination, cyclization and hydrogenation of natural rubber can be used to modify natural rubber.
(2) Black natural rubber has excellent comprehensive physical and mechanical properties.
Natural rubber has good elasticity at room temperature. This is because the molecular chain of natural rubber is amorphous at room temperature and has good flexibility. Its density is 0.9 13g/cm, its elastic modulus is 2-4MPa, which is about one third of that of steel, and its elongation is 300 times that of steel, with the maximum of 1000%. In the range of 0- 100 degrees, the resilience of natural rubber can reach more than 50%-85%.
(3) Thermal aging black natural rubber is a high elastomer at room temperature, and its glass transition temperature is -72 degrees. After heating, it softens slowly, and 130- 140 degrees begins to flow, and it begins to decompose around 200 degrees, and it decomposes violently at 270 degrees.
(4) Black natural rubber has moderate resistance. Medium refers to oil, liquid chemicals, etc. Natural rubber is resistant to cyclohexane, gasoline, benzene and other media, but insoluble in polar acetone and ethanol. , insoluble in water, resistant to 10% hydrofluoric acid, 20% hydrochloric acid, 30% sulfuric acid, 50% sodium hydroxide, etc. Potassium permanganate, potassium dichromate, etc., which are not resistant to strong acid and strong oxidation.
(5) Good processability. Black natural rubber is easy to plasticate, mix, calender, extrude and shape. Because of its high relative molecular weight, wide distribution of equivalent molecular weight and easy breakage of molecular chain, there are a certain number of gel molecules in raw rubber.
What is the reason why the newly produced black rubber outsole is blue for several days?
1. The reason why the newly produced black rubber outsole turns blue in a few days is that the dosage of compounding agent in rubber is too high or the solubility of compounding agent is too high.
2. The rubber outsole can be made of natural rubber or synthetic rubber. Because rubber is a polymer compound. Therefore, rubber outsole shoes have high elasticity and wear resistance, and can withstand repeated bending, stretching and compression without being damaged. It also has the characteristics of acid and alkali resistance, and is suitable for wearing in rainy days. At present, most sports shoes on the market use rubber soles. Like basketball shoes, football shoes, tennis shoes, etc. Because they all belong to strenuous exercise, they all need rubber soles with high wear resistance. In fact, rubber outsole is the collective name of all rubber sports soles. Rubber outsole can be divided into natural rubber outsole, wear rubber outsole, environmental protection rubber outsole, air rubber outsole, air rubber outsole, air rubber outsole and carbon rubber outsole according to specific materials and components.
Through the above introduction, we have learned several characteristics of natural rubber, an excellent material. It is these properties that make it have many advantages and be favored by everyone. It is worth noting that the widespread use of black natural rubber has caused some black-hearted businesses to start making fakes and use a large number of artificially manufactured unqualified materials to make rubber. When choosing to buy, we must pay attention to carefully observe whether the purchased black rubber is real natural rubber, so as to avoid the inconvenience and even the health hazard caused by inferior materials.