A kind of method that takes vermiculite as raw material to prepare PVC heat stabilizer

Abstract

The present invention takes ore as raw material, utilizes the layered structure characteristics of vermiculite, and obtains layered silicon-oxygen tetrahedron and re-prepared layered aluminum-oxygen octahedron by removing one layer of aluminum-oxygen octahedron in the middle of two layers of silicon-oxygen tetrahedrons. , realize the interlayer splitting of vermiculite, and prepare the method for PVC thermal stabilizer. Specifically, the expanded vermiculite is obtained from the vermiculite ore through microwave expansion; and then the ion stirring is used to peel off to obtain the nano-scale vermiculite flakes. According to the fact that the silicon-oxygen tetrahedron is insoluble in acid and the aluminum-oxygen octahedron is easily soluble in acid, the vermiculite is decomposed by acid dissolution to obtain solid layered silica (silica tetrahedron). The acid solution undergoes a fractional precipitation method to remove the iron ions in the solution, then undergoes rapid nucleation, washes to remove impurities such as salt ions, and finally controls the growth of crystals by a hydrothermal method to prepare nanoscale layered hydroxides (aluminum oxide eight surface). The obtained silicon dioxide and hydroxide are successfully mixed with the heat stabilizer and PVC through the solvent replacement and dispersion method, overcoming the problem of agglomeration and redispersion of nanoscale silicon dioxide and hydroxide. The present invention selects the superior mineral vermiculite in my country as the raw material to prepare the PVC heat stabilizer, which has the advantages of wide raw material sources, low cost, simple process, non-toxicity, and easy popularization and application; in addition, the raw ore vermiculite has prepared a highly efficient heat stabilizer , overcome the shortcomings of the existing high price or toxic heat stabilizers such as lead, and have important theoretical and practical significance for promoting the development of high value-added products of vermiculite.

Description

Technical field: [0001] The invention relates to a method for preparing a PVC heat stabilizer by using vermiculite as a raw material, in particular to a method for preparing a PVC heat stabilizer, in particular to a special nontoxic heat stabilizer for PVC pipes. Background technique: [0002] Polyvinyl chloride (PVC) resin is one of the five general-purpose plastics (PE polyethylene, PP polypropylene, PVC polyvinyl chloride, PS polystyrene, ABS), and is a widely used thermoplastic. PVC material has high mechanical strength, low price, good chemical corrosion resistance (resistance to concentrated hydrochloric acid, 90% sulfuric acid, 60% nitric acid and 20% sodium hydroxide), good electrical insulation and hard to burn (flame retardant value is above 40) and other advantages, it has stable physical and chemical properties, insoluble in water, alcohol, gasoline, low gas and water vapor leakage, etc. It is widely used in engineering construction, food packaging, electrical an...

AI Technical Summary

Problems solved by technology

[0004] In the 1930s, the appearance of lead salts first solved the problem of thermal degradation of PVC, and was also the first heat stabilizer to be used. However, with the enhancement of people's awareness of environmental protection, the problems of high toxicity and serious pollution have greatly limited its application.

[0005] my country's heat stabilizer industry is still facing many problems, such as lack of sufficient research and development funds, lack of high-level professionals, disconnection between scientific research and production; insufficient original innovation of products, few varieties; slow environmental protection process, unreasonable product structure; Small production scale, uneven product quality, etc.

The existence of the above problems seriously limits the development of my country's heat stabilizer industry

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