Thermal and optical properties of heat-resistant core materials in plastic optical fiber

Abstract

Recently the application of plastic optical fiber (POF) in automotives and planes demands the heatresistant and high refractive index core materials. We synthesized polyglutarimides (PGIs) via imidization of PMMA with primary amines under high pressure and high temperature and investigated thermal and optical properties by varying the molar ratio of amines and the type of amines (ethyl amine vs. isopropyl amine). The degree of imidization was calculated based on the peak intensity in H-1 NMR and FTIR. We found that the glass transition temperature (T-g) of PGIs increased over 30 degrees C compared to the traditional core materials in POE PMMA, and they are stable up to 300 similar to 400 degrees C. PGIs synthesized with ethyl amine show the better heat resistance than those with isopropyl amines. Additionally they show the comparable transparency and higher refractive index than PMMA. It implies that they can be utilized as the excellent photo-efficient and heat-resistant core materials in POF.