A kind of preparation, separation and purification method of latent curing agent microcapsules with temperature-responsive controlled release characteristics

Abstract

Relating to synthesis and optimization of latent curing agents, the invention provides a preparation and separation and purification method for a specific curing agent controlled release system with temperature responsiveness. According to the invention, a specific method is employed to prepare the specific curing agent so as to obtain a microcapsule with specific purpose. Through optimization of the preparation process, the use of polyvinyl alcohol and other stabilizers can be avoided, thus being conducive to separation and purification and drying at the later period. Also, the used reagents are all low toxic or non-toxic, and have very low environmental pollution. Single and pure thermoplastic plastic like polystyrene is selected as the coating material, which can melt at certain temperature and the release the curing agent so as to carry out curing reaction. Through selection of the solvent, rotation speed and feed ratio, microcapsules with different particle size distribution and curing agent content can be obtained. After centrifugation, a discontinuous timing ultrasonic method is carried out in absolute ethanol to prepare the curing agent microcapsule with very little impurity content and very good dispersibility, and agglomeration phenomenon does not appear.

Description

technical field [0001] The invention relates to a preparation and treatment method of latent curing agent microcapsules with temperature response controlled release characteristics, in particular to microencapsulation and dispersion treatment of curing agent diurea. Background technique [0002] Curing agent is a kind of substance or mixture that promotes or controls the curing reaction. Especially in the use of epoxy resin must add curing agent. In order to obtain an epoxy cured product with excellent mechanical and heat resistance properties, it is often necessary to cure at a higher temperature, but the material product at a higher temperature will generate greater internal stress, the size is difficult to control, and the energy consumption is large, so the low temperature curing agent gradually received people's attention. [0003] However, low-temperature curing agents generally have high reactivity, are not easy to store at room temperature, and easily react with ox...

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Problems solved by technology

[0006] Diurea is a kind of commonly used epoxy resin curing agent and accelerator. It has high curing activity, but the epoxy resin prepreg prepared with it is not stored for a long time at room temperature and will cure soon. reaction, which makes the prepreg unusable, which also leads to a greatly reduced operating time during processing, which is not conducive to processing operations

[0008] Traditional microcapsule preparation methods mostly use in-situ polymerization and interfacial polymerization. Using these methods will cause problems such as long reaction time, slow polymerization speed, and difficult control of the reaction. At the same time, there are disadvantages such as complex reaction equipment and high cost of material preparation.

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