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Source:Transform the World with Simplicity
PA (polyamide, Polyamide) is a kind of engineering plastics widely used in chemical, automotive, electronics, aerospace and other fields. In the field of raw materials for chemical production, there are two main methods for manufacturing PA: polycondensation and ring-opening polymerization. This article will detail these two manufacturing methods.
1. polycondensation method
polycondensation method is through the dibasic acid and diamine reaction to generate polyamide salt, and then through high temperature melting, dehydration, cyclization and other steps, and finally get PA. The specific steps are as follows:
1. Ingredients: according to a certain proportion of dibasic acid and diamine are added into the ingredient tank, and an appropriate amount of water is added for stirring to make it fully react to generate polyamide salt.
2. Melting: Polyamide salt is added to a high-temperature melter and heated to a certain temperature to melt it into a fluid.
3. Dehydration: In a high-temperature molten state, water is extracted by a vacuum pump to dehydrate the polyamide salt.
4. Cyclization: The dehydrated polyamide salt undergoes a cyclization reaction at a high temperature to produce PA.
PA manufactured by
polycondensation has a compact molecular structure, excellent mechanical properties, and high heat resistance, wear resistance and corrosion resistance. However, the production process of this method is complicated, requires high temperature and vacuum conditions, and consumes a lot of energy.
2. ring-opening polymerization method
ring-opening polymerization method is to produce PA by ring-opening polymerization of cyclic monomer. The specific steps are as follows:
1. Preparation of cyclic monomers: cyclic monomers are generated by the lactone reaction of diamines and dibasic acids.
2. ring-opening polymerization: under the action of a catalyst, the cyclic monomer is heated to a certain temperature to make its ring-opening polymerization to generate PA.
PA manufactured
ring-opening polymerization has high molecular weight, regular molecular structure, and good processability and mechanical properties. At the same time, the production process of this method is relatively simple and the energy consumption is low.
In general, both polycondensation and ring-opening polymerization have their advantages and disadvantages, and the choice of which method depends on the specific product requirements and production process. In the actual production process, it is necessary to comprehensively consider factors such as product performance requirements, production costs, and environmental protection requirements to select the most suitable manufacturing method.
No matter which method is used, the manufacture of PA requires strict control of raw material quality, reaction temperature and time, processing process and other factors to ensure product quality and performance. At the same time, it is also necessary to pay attention to environmental protection and safety production issues to ensure that the production process complies with relevant laws, regulations and standards.
the future, with the continuous progress of science and technology and the improvement of environmental awareness, PA manufacturing methods will continue to optimize and improve, improve production efficiency, reduce energy consumption and reduce environmental pollution, and contribute to the sustainable development of the chemical industry.