Synthesis of Polyamide-Based Microcapsules via Interfacial Polymerization: Effect of Key Process Parameters

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Polyamide microcapsules (PA MCs) show promise due to excellent barrier properties.
• Their application is hindered by the inherent fragility of the polyamide membrane.

Purpose of the Study:

• To prepare fully aliphatic PA MCs using ethylene diamine and sebacoyl chloride via interfacial polymerization.
• To investigate the impact of key parameters on process yield and microcapsule characteristics.

Main Methods:

• Interfacial polymerization of ethylene diamine and sebacoyl chloride.
• Systematic variation of monomers ratio, core solvent, stirring rate, and polymerization time.
• Analysis of microcapsule properties including shell molecular weight, thermal behavior, size, and morphology.

Main Results:

• Process yield is significantly influenced by the core solvent's effect on diamine diffusion.
• Spherical PA MCs (14-90 μm) with 33% yield were achieved using toluene as the core solvent.
• Milder stirring improved microcapsule morphology, but mechanical properties require further enhancement.

Conclusions:

• Toluene is an effective core solvent for producing PA MCs with good yield and morphology.
• Process optimization, particularly stirring, can refine microcapsule characteristics.
• Enhancing the mechanical robustness of these PA MCs remains a critical area for future research.