Method for coagulating natural rubber fresh latex by enzymatic method

Abstract

The invention discloses a method for coagulating natural rubber fresh latex by an enzymatic method, which relates to technology for coagulating the natural rubber. The method comprises the following steps of: determining the weight of natural rubber fresh latex to be coagulated and weighing protease which is 0.05 to 2 percent based on the weight of the fresh latex; dissolving the protease in water, wherein the using amount of water is 10 percent based on the weight of the fresh latex; then adding the aqueous solution of protease into the fresh latex and stirring uniformly; and standing and coagulating. In the method, the natural rubber fresh latex is coagulated according to the characteristic that papain decomposes proteins and damages the stability of the latex, and the method is easy tooperate, and has high coagulation speed and strong adaptability, and by the method, not only the fresh latex without ammonia can be coagulated, but also the fresh latex with ammonia content up to 0.2percent can be completely coagulated, and the physicochemical performance of the product is not influenced. Hydrolytic protease and alkaline protease also have the same effect.

Description

【Technical Field】 [0001] The invention relates to the coagulation process of natural rubber. 【Background technique】 [0002] Natural fresh rubber latex is the milk secreted by the Brazilian Hevea rubber tree. In addition to rubber hydrocarbons and water, this emulsion also contains a small amount of non-gum substances such as protein, esters, organic acids and sugars. In general, the rubber particles in the latex are protected by an electric double layer composed of hydrophilic substances such as proteins and lipids. The latex can maintain a stable colloidal state. If the fresh latex is contaminated by microorganisms, or add acid or inorganic salt , The protective layer of the latex is weakened or eliminated, so that the latex loses its stability, so that gelation or coagulation occurs. After the coagulation, the coagulated rubber block is made into natural rubber through processes such as creping, granulation and drying. In terms of production, standard natural rubber is coagul...

AI Technical Summary

Problems solved by technology

The natural coagulation process is limited in its application because the coagulation time takes tens of hours; the inorganic salt coagulation process is rarely used because it has a lot of adverse effects on the properties of natural rubber; currently the most common use is acid (acetic acid or formic acid) coagulation process, there are disadvantages such as high coagulation cost, strong corrosion, strong irritating odor, great impact on the performance of natural rubber, and environmental pollution by the discharged rubber-making wastewater; biological coagulation is a rubber-making process that uses biological culture fluid to coagulate fresh latex. The main method is The latex is coagulated by adding biological culture solution into the fresh latex. The coagulation cost is low and the product quality is good. However, because ammonia is a fungicide, the biological coagulation method is not suitable for the fresh latex preserved by adding ammonia. It is used in production limited