Natural rubber has excellent elasticity and resilience, high mechanical strength, wear resistance and tear resistance, and is an important raw material for the manufacture of tires, hoses, tapes, rubber shoes, seals, adhesive tapes, rubber sheets and other rubber products. Rubber hydrocarbons account for 92%-95% of natural rubber, which determines the performance of natural rubber; The higher the hydrocarbon content of the rubber, the better the physical and mechanical properties of the rubber compound. The non-rubber part of natural rubber will also have a certain impact on the physical and mechanical properties and processing properties of the rubber compound.
1. The effect of protein on the properties of natural rubber
The protein content affects the vulcanization properties, antioxidant properties and physical properties of natural rubber, and nitrogen-containing compounds are all protein-like substances. In general, protein has the effect of preventing aging, and when its content is less than 1%, the heat aging resistance of natural rubber will be significantly reduced; The protein E4LYY36 content is too high, the natural rubber has high heat generation and poor dynamic performance; In addition, protein has strong water absorption and electrical conductivity, and high content will lead to moisture absorption, mildew and decreased insulation of natural rubber.
The presence of proteins also affects the hardness, swelling and cross-linking structure of natural rubber; The basic nitrides and alcohol-soluble proteins in proteins can facilitate the vulcanization process of natural rubber.
2. Effect of acetone extract on the properties of natural rubber
Acetone extract refers to the substances in rubber that can be dissolved in acetone, mainly higher fatty acids and sterols, which mainly affect the vulcanization activity, plasticity, anti-aging and so on of rubber: higher fatty acids are a vulcanization active agent, which can promote vulcanization and increase the plasticity of rubber compounds; Sterols and some highly reducing substances have the effect of preventing aging.
3. The effect of ash content on the properties of natural rubber
The ash in natural rubber refers to the combustion products of inorganic salts and foreign impurities existing in the rubber itself, phosphate or sulfate of metal elements such as potassium, sodium, calcium, magnesium and aluminum, non-rubber substances such as sediment and rust, copper, manganese, iron and other metal elements and their salts; The ash content can reflect the content of inorganic impurities in natural rubber, which has a direct impact on the performance of rubber products, such as aging resistance, electrical insulation, etc.
Calcium, magnesium, potassium, sodium, iron, phosphorus and other compounds in natural rubber have greater water absorption, which reduces the electrical insulation of rubber compounds; Trace amounts of copper, manganese and other valence ions will greatly accelerate the aging rate of rubber.
4. The effect of moisture on the properties of natural rubber
There is too much moisture in natural rubber, it is easy to mold during storage, the compounding agent is easy to agglomerate and not easy to disperse during mixing, it is easy to produce bubbles in the process of rolling and extruding, and bubbles or sponges are produced during vulcanization; Moisture up to 1% can be removed during natural rubber processing.
Natural rubber has high mechanical strength and good elasticity, and is widely used in the production of various rubber products. Rubber hydrocarbons, as the main components, determine the basic properties of rubber, while non-rubber components such as protein, acetone extract, ash and moisture, although the content is not high, has a significant impact on the vulcanization, oxidation resistance, physical and mechanical properties and processing properties of rubber. Controlling the content of these non-rubber components is essential to optimize the performance and processing of natural rubber.
At present, many rubber products processing enterprises with natural rubber as the main raw material will add a part of latex reclaimed rubber to the formula in order to reduce costs, or directly use latex reclaimed rubber instead of natural rubber; Acetone extract, ash and moisture can also be used as important indicators to judge the quality of latex reclaimed rubber; Understanding the impact of these components on the performance of rubber compounds can help us select more suitable natural reclaimed rubber products and reduce more raw material costs while ensuring the quality of the finished product.
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