Effect of thermal aging on the optical, dynamic mechanical, and morphological properties of phenylmethylsiloxane-modified epoxy for use as an LED encapsulant

► The effects of the properties of the hybrids on the performance of LEDs. ► Long-term thermal aging of hybrids and LEDs at 150 °C. ► The hybrids with PMSE were highly transparent and optical stable. ► The molecular rearrangement of hybrids was studied by DMA and TEM. ► The hybrid with stable properties contributed to the most stable LED performance.