High-efficiency flame retardency of epoxy resin composites with perfect T-8 caged phosphorus containing polyhedral oligomeric silsesquioxanes (P-POSSs)

摘要

Phosphorus containing polyhedral oligomeric silsesquioxanes (P-POSSs) of perfect T-8 caged structures was designed as a new class of flame retardant. Phosphorus containing POSS combine several advantages from phosphorus based flame retardant and nanostructure inorganic-organic hybrid materials. Three phosphorus containing POSSs were synthesized by the addition reaction of octa vinyl PUSS with diphenylphosphine (DPP), diphenylphosphine oxide (DPOP), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), respectively. The impacts of DPP-POSS, DPOP-POSS, and DOPO-POSS on the pyrolysis and fire behavior of an epoxy resin (DGEBA/DDS) were investigated under temperature programmed heating (TGA-FTIR), forced flaming conditions (cone calorimeter) and small flame conditions (LOI and UL-94). The flame retardant performance and mechanisms of DPP-POSS, DPOP-POSS, and DOPO-POSS were assessed and discussed in detail based on TGA-FTIR, XPS, and FUR. The main flame retardant activity of DPP-POSS, DPOP-POSS, and DOPO-POSS are in the especially strong condensed phase activity through charring and intumescence due to the synergistic between phosphorus and silicon in these POSSs. (C) 2016 Elsevier Ltd. All rights reserved.