Nuclear chemistry

Oligomer

Polymerization

Engineering

Char

Polymer chemistry

Thermogravimetric analysis

Epoxy

Pyrolysis

Materials science

Telecommunications

Computer science

Chemical engineering

Cone calorimeter

Ammonium polyphosphate

Polymer

Physics

Organic chemistry

Piperazine

Degradation (telecommunications)

Thermal

Flammability

Composite material

Gel permeation chromatography

Chemistry

Meteorology

Fourier transform infrared spectroscopy

Fire retardant

Thermal stability

Intumescent

Polymer Degradation and Stability

In this work, a novel P/N-containing oligomer poly(piperazine phenylphosphamide) (BPOPA) was synthesized via the polymerization reaction of phenylphosphonic dichloride with piperazine. Its structure was characterized by Fourier transformation infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), elemental analysis (EA) and gel permeation chromatography (GPC). It was used to enhance the flame retardancy of epoxy resin/ammonium polyphosphate (APP). As expected, improvement in flame retardancy of EP/APP was observed. In detail, EP containing 10 wt% APP alone possessed a LOI value of 30.2% but UL-94 no rating. When both 7.5 wt% APP and 2.5 wt% BPOPA were added into EP, EP/7.5APP/2.5BPOPA passed a UL-94 V-0 rating with a LOI value of 33.1%. Moreover, EP/7.5APP/2.5BPOPA presented much lower values of the peak of heat release rate (PHRR) and total smoke production (TSP) compared with EP/10APP. The flame-retardant mechanism was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis/infrared spectrometry (TG-IR). Results illustrated that EP/7.5APP/2.5BPOPA mainly functioned in condensed phase which was associated with the formation of more compact char layer.

Influence of a novel P/N-containing oligomer on flame retardancy and thermal degradation of intumescent flame-retardant epoxy resin