Photo-polymerization Property of the Photosensitive Core-shell Structured Microcapsule Material

Abstract

The sub-micrometer core-shell microcapsule is synthesized by interfacial polymerization method, with photocrosslinkable resin TMPTA and photoinitiators ITX, TPO encapsulated as core functional compounds. FT-IR detection shows the polyurea chemical structure of the microcapsule shell, and TG analysis verifies that the microcapsule is thermal stable below 230°C. The photopolymerization process in microcapsule is measured quantitatively from the variance of the C=C bond absorbance at 1635cm^-1. The photopolymerization degree in microcapsule increases with rise of exposure time, and achieves stabilized photopolymerization percentage of 39.4% after 30s, which is lower in comparison with 60% of the unencapsulated resin/photoinitiators mixture exposed after 15s. The decrease of photopolymerized degree in microcapsules is ascribed to the UV irradiation attenuation when transmitted through the microcapsule shell. The photosensitive microcapsules can act as basic functional cells in responding to photo stimuli at sub-micrometer scale.