Continuous Nylon Polymerization Using a Reactive Polyamide Medium
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Solution Overview
Problem
Existing nylon polymerization methods, such as the nylon salt process and melt polymerization, face challenges including complex processes, high energy consumption, water usage leading to waste, low production efficiency, and difficulty in achieving continuous production due to issues with heat management and material handling.
Innovation Solution
A continuous polymerization method for nylon using polyamide resin as a reactive dispersion medium, allowing for continuous addition and mixing of starting materials in a controlled heat release environment, utilizing screw and tubular reactors for efficient mixing and polymerization, and omitting the need for aqueous solution preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the nylon salt process is used with aqueous solution preparation, then the polymerization can proceed smoothly, but the process becomes complex and continuous production is difficult to achieve
Solution Approach 1:
The invention extracts and removes the aqueous solution preparation step from the polymerization process. By using a melt polymerization method where diamine is added directly to molten dibasic acid without prior salt preparation in water, the complex aqueous processing steps are eliminated while maintaining polymerization effectiveness
Solution Approach 2:
The invention implements continuous production by establishing a continuous melt polymerization process. The polymerization reactor operates continuously with continuous feeding of raw materials and continuous discharge of product, eliminating the batch processing nature of traditional nylon salt methods
2Reliability
If water is added as a dispersant in melt polycondensation, then the quality stability of the final product is ensured, but a large amount of water is consumed causing waste
Solution Approach 1:
The invention extracts and eliminates the water dispersant from the polymerization system. By using the dibasic acid melt itself as the reaction medium and dispersing the diamine directly in the molten acid, water is completely removed from the process, eliminating both consumption and waste disposal issues
Solution Approach 2:
The dibasic acid melt serves as an intermediary medium that fulfills the dispersal function previously performed by water. The molten dibasic acid acts as a solvent and reaction medium simultaneously, allowing uniform mixing and reaction without requiring additional water
3Reliability
If water is evaporated during the polycondensation process, then the polycondensation reaction can proceed, but a lot of energy is consumed
Solution Approach 1:
The invention extracts water elimination from the polycondensation process by using alternative starting materials. By employing dibasic acid esters instead of dibasic acids, the byproduct becomes alcohol rather than water, which has lower boiling point and can be removed more easily with less energy input
Solution Approach 2:
The invention changes the chemical parameters of the reaction system by substituting dibasic acid with dibasic acid ester. This parameter change alters the byproduct from water (high boiling point, high energy required for evaporation) to alcohol (lower boiling point, lower energy required for removal)
Solution Approach 3:
The invention uses a composite approach by combining dibasic acid ester and diamine as starting materials. This composite material system enables polycondensation to proceed with alcohol as byproduct, which is easier to remove than water, thereby reducing energy consumption
4Reliability
If diamine is added slowly to avoid concentrated heat release and decomposition, then decomposition is avoided, but the addition time takes several hours greatly limiting production efficiency
Solution Approach 1:
The invention applies preliminary action by pre-cooling the diamine before addition and pre-heating the dibasic acid to appropriate temperatures. This preliminary temperature control allows for faster addition rates without causing runaway heat release or decomposition, thereby improving production efficiency
Solution Approach 2:
The invention implements feedback control by monitoring the temperature during the addition process and adjusting the addition rate accordingly. When temperature rises within a safe range, the addition rate can be increased; when approaching critical thresholds, the rate is automatically reduced, optimizing both safety and efficiency
5Loss of substance
If diamine with higher boiling point is used to avoid losses during binding, then diamine losses are reduced, but the reaction efficiency is lowered
Solution Approach 1:
The invention changes the physical parameters of the reaction environment by maintaining optimized temperature and pressure conditions. By controlling the reaction temperature below the diamine boiling point and applying appropriate vacuum for byproduct removal, diamine volatility is minimized without requiring higher boiling point substitutes, thus preserving reaction efficiency
Solution Approach 2:
The invention implements continuous polymerization where diamine is continuously added to the reacting system rather than being charged all at once. This continuous addition maintains lower local concentrations of diamine, reducing volatilization losses while keeping the overall reaction proceeding efficiently at high rate
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method achieves high production efficiency, reduces energy consumption, minimizes waste, and ensures stable product quality by uniformly dispersing materials, suitable for continuous production and flexible product variation.
Implementation Method 1
polymerization starting materials comprise polymerization monomers... and polymerization steps comprise: continuously adding the polymerization starting materials into a material mixing device in proportion, so that the starting materials are mixed and reacted in the material mixing device
Implementation Method 2
reactive dispersion medium polyamide... so that the starting materials are mixed and reacted in the material mixing device to form a melt that is continuously conveyed, and reacting the evenly dispersed melt
Implementation Method 3
controlled heat release environment... In order to avoid a large amount of concentrated heat release during binding of the dibasic acid and the diamine in feeding
Data Source
AI summary
A continuous polymerization method for nylon. Polymerization starting materials comprise, in parts by mass, 5-60 parts of polymerization monomer dibasic acid and/or dibasic acid ester, 3-50 parts of diamine, and 10-90 parts of reactive dispersion medium polyamide. Polymerization steps comprise: continuously adding the polymerization starting materials into a material mixing device in proportion, so that the raw materials are mixed and reacted in the material mixing device to form a continuously conveyed melt, and reacting the evenly dispersed melt in a subsequent polymerization device until nylon is polymerized to reach a required molecular weight. The method is an efficient and environment-friendly polymerization method for nylon.