Method for regulating and controlling micro-nano structure of polyvinyl chloride resin particles

Abstract

The invention relates to a method for regulating and controlling a micro-nano structure of polyvinyl chloride resin particles. The method sequentially comprises the following steps: preparation of an auxiliary agent, feeding of a polymerization kettle, material activation, polymerization reaction control, discharging of PVC slurry, steam stripping and drying. According to the method, the limitation of adjusting the PVC macroscopic particles by adjusting the dispersing agent and the stirring speed in the traditional process is overcome, the polymerization chemical reaction rate is controlled by adjusting the temperature, and the method is simple, convenient and easy to implement, high in operability and good in reproducibility. The method can be widely applied to the production process of the special polyvinyl chloride resin for gas-solid phase method chlorination.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for regulating the micro-nano structure of polyvinyl chloride resin particles. Background technique [0002] Chlorinated polyvinyl chloride (CPVC) is obtained by further chlorination of polyvinyl chloride (PVC), and is a new type of polymer elastomer material between rubber and plastic. After the PVC resin is chlorinated, the irregularity of the molecular bond increases, the polarity increases, the solubility of the resin increases, and the chemical stability improves, thereby improving the material's heat resistance, acid, alkali, salt, oxidant, etc. Corrosion. Compared with PVC, CPVC has greatly improved its heat resistance, corrosion resistance, flame retardant and self-extinguishing properties, and mechanical properties. It is widely used in building materials, electrical, chemical, metallurgy, medicine, coatings and other fields. Applications. [0003] A...

AI Technical Summary

Problems solved by technology

In the chlorinated polyvinyl chloride process produced by the gas-solid phase method, the chlorine gas molecules in the gas phase enter through the internal pores of the particles and undergo grafting reactions with the PVC molecular chains. The grafting rate and grafting uniformity are affected by the abundance of pores and the uniformity of pores. At the same time, the heat of grafting reaction is removed by circulating vulcanized chlorine gas to produce polyvinyl chloride resin. By adjusting the stirring speed of the polymerization tank and the type and amount of dispersant, the polyvinyl chloride resin can be significantly changed macroscopically. The particle shape of vinyl resin can adjust the particle size distribution and the roundness of the shape, and the internal void structure is also improved, but it is difficult to complete the regulation of the deep micro-nano structure of the resin. The specificity of ethylene production and application is not strong, especially when the gas-solid phase chlorination process is adopted, it is difficult to remove heat, which will cause poor thermal stability of chlorinated polyvinyl chloride resin

General-purpose loose polyvinyl chloride resin is used for processing PVC plastic products. The PVC particles are uniform and can meet the processing and plasticization requirements if they meet a certain microporous structure. The external skin structure, internal pore density and uniformity of loose polyvinyl chloride resin are not enough to satisfy the free and uniform diffusion of grafted monomers into the interior