Flame Retardancy and Thermal Degradation Behaviors of Thiol-Ene Composites Containing a Novel Phosphorus and Silicon-Containing Flame Retardant

Abstract

In this article, a novel phosphorus and silicon-containing flame retardant (DOPO-V-PA) was synthesized via condensation reaction and then added into thiol-ene (TE) to prepare a flame-retardant composite. The results of cone calorimeter measurement demonstrated that, compared with pure TE, 22.7% and 53.2% reduction of TE/DOPO-V-PA (thiol-ene/9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-vinyltrimethoxysilane-phenyltrimethoxysilane-(3-aminopropyl)trimethoxysilane copolymer) was found for the peak heat release rate (PHRR) and total heat release (THR), respectively. The thermal degradation of TE composites was investigated by the TGA measurement under non-isothermal conditions, and kinetic parameters were both calculated by the Kissinger and Flynn-Wall-Ozawa methods. It was indicated that the activation energies of TE at conversions exceeding 50% were enhanced by the incorporation of DOPO-V-PA for the whole conversion range.

Keywords: activation energy; flame retardancy; kinetics; thermal degradation; thiol-ene.

Figure 1

Preparation route of DOPO-V-PA.

Figure 2

Chemical structure of thiol-ene.

Figure 3

The heat release rate (a) and total heat release (b) curves for TE composites.

Figure 4

Residual char images of TE (a) and FRTE (b) after CONE measurement.

Figure 5

Thermal stability of TE composites.

Figure 6

TGA curves of TE (a) and FRTE (b) composites.

Figure 7

DTG curves of TE (a) and FRTE (b) composites.

Figure 8

$$\ln (\frac{\beta }{T_{\max }^2})$$ vs. $$\frac{1}{T_{\max }}$$ curves of TE and FRTE.

Figure 9

The plots of $$\lg (\beta )$$ vs. 1000/T of TE (a) and FRTE (b).

Figure 10

Activation energy curves of TE and FRTE by the Flynn-Wall-Ozawa method.