Synthesis of tris(2-hydroxyethyl) isocyanurate homopolymer and its application in intumescent flame retarded polypropylene

摘要

A macromolecular homopolymer (named as Homo-THEIC) was synthesized through self-etherification of tris(2-hydroxyethyl) isocyanurate (THEIC) molecules and used as charring agent. Its chemical structure was characterized by FTIR and C-13-NMR. The charring agent was mixed with ammonium polyphosphate (APP) and applied in flame retarded polypropylene (PP). Results of UL-94, LOI, and cone calorimeter test showed that the LOI of flame retarded PP can reach 32.8% and UL-94 V-0 rating can be achieved at 30 wt % loading. The heat release rate and smoke production rate during the combustion of PP were substantially reduced. TGA results indicated that the synergistic effect between APP and Homo-THEIC existed and the addition of intumescent flame retardant (IFR) dramatically enhanced the thermal stability of PP. According to the results of TGA, SEM, TG-FTIR, FTIR, and Raman, the char forming process of IFR can be separated into three stages: the formation of viscous phosphate ester (T-onset-330 degrees C), the expanding process along with the decomposition of phosphate ester and the release of a large amount of gases (330-480 degrees C), and the final formation of graphitic-like char without any expanding feature (480-670 degrees C). (C) 2016 Wiley Periodicals, Inc.