Thermally stable network-structured polysiloxane hybrimers with high refractive index for optical applications

Area of Science:

• Materials Science
• Polymer Chemistry
• Optoelectronics

Background:

• Advanced LED applications require high-performance optical encapsulants.
• Conventional encapsulants like epoxy resins and silicones have limitations in optical and thermal properties.

Purpose of the Study:

• To synthesize network-structured polysiloxane hybrimers (NPH 1-3) for high-performance optical encapsulation.
• To evaluate the optical, mechanical, and thermal properties of NPH 3 for advanced LED applications.

Main Methods:

• Synthesis of network-structured polysiloxane hybrimers (NPH 1-3).
• Characterization of optical properties (refractive index, transmittance) at various wavelengths.
• Assessment of mechanical properties (hardness) and curing kinetics.
• Evaluation of thermal stability through prolonged high-temperature aging.

Main Results:

• NPH 3 exhibited a high refractive index (1.61 at 450 nm) and outstanding transmittance (96.5% at 450 nm).
• NPH 3 showed rapid curing (4.5 hours) and high hardness (76.2 Shore D), outperforming conventional materials.
• Exceptional thermal stability was observed, with minimal transmittance decrease after aging at 200 °C for 72 h.
• NPH 3 demonstrated enhanced light extraction efficiency due to minimized internal reflections.

Conclusions:

• NPH 3 possesses a well-balanced set of properties, including high optical transparency, rapid curing, and enhanced mechanical strength.
• Its superior thermal resilience and optical characteristics make it highly attractive for advanced optoelectronic systems.
• NPH 3 is a promising candidate for next-generation encapsulants in demanding applications requiring long-term reliability and high efficiency.