Synthesis and characterization of a high refractive diglycidyl ether of thiodibenzenethiol epoxy resin

Abstract

High refractive index of epoxy resins used as encapsulant in lightemitting diode (LED) is essential in improving the light extraction efficiency, reducing heat and prolonging the service life of LED packages. In this study, diglycidyl ether of thiodibenzenethiol (DGETDBT), an epoxy resin with high refractive index, was synthesized via a novel method and its chemical structure was characterized with Fourier-transform infrared (FTIR) spectrometer and 1 H NMR spectrometer. Using m-xylylenediamine (MXDA) as curing agent, the curing behavior of DGETDBT was studied by differential scanning calorimetry (DSC) and was compared with that of diglycidyl ether of bisphenol A (DGEBA), a generally used encapsulant in LED. The thermal behavior and optical performance of these two resins were investigated with thermogravimetric analyses, UV-Vis scanning spectrophotometer, and Abbe refractometer, respectively. The results showed that DGETDBT/MXDA resin demonstrated similar curing and thermal behavior to DGEBA/MXDA resin. But its refractive index reaches 1.698, which is significantly

Synthesis and characterization of high refractive epoxy prepolymers with different molecular structures

“…13,14 Conclusion Three kinds of high refractive epoxy prepolymers, DGEOP, DGETP and DGETDBT, were synthesized via a two-step method, and their chemical structures were characterized using FTIR and 1 H NMR spectra. The results showed that sulfur atoms in DGETDBT and DGETP had contributed to an obvious increase in their refractive index, while the methyl group in DGEBA cut down its refractive index according to some recent literatures.…”

“…The results showed that sulfur atoms in DGETDBT and DGETP had contributed to an obvious increase in their refractive index, while the methyl group in DGEBA cut down its refractive index according to some recent literatures. 13,14…”

“…8,9 At present, introducing sulfur element into polymer is regarded as one of the best methods to realize high refractive index. [10][11][12] Katsumasa et al 13 and Luo et al 14 publicized diglycidyl ether of thiodibenzenethiol (DGETDBT) epoxy prepolymer with the refractive index of 1.669, which is the ever-reported highest refractive index of extant epoxy prepolymers. But the influence of molecular structure on the refractive index of epoxy prepolymer is not clear.…”

Nonisothermal Crystallization Behaviour of a Novel Cycloaliphatic Microcrystalline Poly(4,4'-Aminocyclohexyl Methylene Dodecanedicarboxylamide)

“…Over the past decade, high performance optical polymeric materials have been attracting much interest in both the industrial and the scientific fields [1][2][3] . As we know, mechanical and physical properties of polymeric materials are strongly dependent on the condense structure of polymers.…”