Xiongfa Yang

A convenient method for preparation of hydroxyl silicone oils with ring opening polymerization of octamethylcyclotetrasiloxane (D4)

GRAPHICAL ABSTRACT Abstract Hydroxyl silicone can be prepared at a mild polymerization temperature with a moderately high yield via ring opening polymerization of D4 catalyzed by rare earth solid super acid SO42−/TiO2/Ln3+. The outstanding advantage of the method was that the viscosities of the products can be conveniently controlled by adjusting polymerization time, temperature, and the amount of water. The products were characterized by size-exclusion chromatography, 1H-nuclear magnetic resonance, and Fourier transform-infrared spectroscopy. A cationic coordination-insertion polymerization mechanism was also proposed.

A Low Temperature Vulcanized Transparent Silane Modified Epoxy Resins for LED Filament Bulb Package

In this work, low-temperature vulcanized, transparent silane modified epoxy resins for LED filament bulb package were prepared. Firstly, transparent silane modified epoxy resins were produced through a controllable sol-gel method using γ-(2,3-epoxypropoxy)propytrimethoxysilane and dimethyldiethoxylsilane. The features of the reaction were investigated and the products were characterized in detail. Subsequently, various curing agents were explored to prepare transparent silane modified epoxy resins. The silane modified epoxy resins cured by PEA-230 at a fairly low temperature (40 °C/2 h then 60 °C/1 h) exhibited excellent thermal stability with a thermal degradation temperature as high as 316.5 °C and adjustable hardness between 40−60 shore A. The application tests showed the materials obtained were good candidates for LED filament bulb package.