Efficient Preparation of Core-Shell Particles via Photopolymerization for Toughening Photocurable Resins.

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Core-shell particles are crucial for enhancing resin toughness.
• Existing large-scale preparation methods for core-shell particles are often inconvenient and inefficient.

Purpose of the Study:

• To develop an efficient and simple method for large-scale fabrication of core-shell particles.
• To investigate the toughening effect of these core-shell particles on resin composites.

Main Methods:

• Fabrication of core-shell particles via photopolymerization and phase separation within emulsion droplets.
• Utilized two photocurable prepolymers with differing hydrophilicity dispersed in an aqueous solution.
• Controlled core-shell ratio and particle size through adjustment of prepolymer concentrations and processing conditions.

Main Results:

• Achieved efficient and scalable production of core-shell particles with adjustable size and core-shell ratio.
• Optimal core-shell particles (1:1 ratio, 1 μm size, 7.5 wt% concentration) significantly enhanced resin toughness, impact strength, flexural strength, and fracture toughness (K_IC) by 52%, 8.4%, 30.8%, and 288.4%, respectively.
• Addition of core-shell particles minimally affected the glass transition temperature (T_g) and viscosity of the resin system.

Conclusions:

• The developed method provides a convenient and efficient route for large-scale core-shell particle preparation.
• The core-shell particles effectively toughen resin composites without negatively impacting thermal properties or processability.
• This study offers a valuable strategy for designing advanced toughened resin materials.