Flame Retarding and Strengthening Poly(ethylene 2,5-furandicarboxylate-co-ethylene terephthalate) Using Phosphonate Containing Genistein

Abstract

A b i o -b a s e d p h o s p h o n a t e 4 -( 7 -((diphenylphosphoryl)oxy)-5-hydroxy-4-oxo-4H-chromen-3-yl)phenyl diphenylphosphinate (DPGE) was synthesized using diphenylphosphinic chloride and genistein. DPGE was used to modify the flame retardancy of poly(ethylene 2,5-furandicarboxylate-co-ethylene terephthalate) (PEFT20) containing 20 mol % 2,5-furandicarboxylic acid. PEFT20 containing 8 wt % DPGE displays a UL-94 V0 rating and a limiting oxygen index of 29.8 vol %. The flame retardant mode is the comprehensive effects of melting-away, gas phase, and condensed phase induced by DPGE. In addition, triglycidyl isocyanurate (TGIC) was incorporated to regulate the mechanical performance of PEFT20/DPGE. The flexural and impact strengths of PEFT20/DPGE are modified greatly. The coupling reactions between PEFT20 and TGIC increase the molecular weight and mechanical properties of PEFT20 blends. But, TGIC counteracts the melting-away effect caused by DPGE. Therefore, too much TGIC causes the decrease in flame retardancy.

Fire Retardancy of Poly(ethylene 2,5-furandicarboxylate-co-ethylene terephthalate) Regulated by Phosphinate

“…DOPO–DP may modify the fire retardancy of PEFT by melting-away mode according to the above results. This is consistent with ref in which PEFT with 8 wt % DPGE is classified the UL-94 V0, so DOPO–DP is more efficient than DPGE in PEFT …”

“…These intermediates are generated due to oxidative cross-linking, but they are unstable in air and will continue to decompose at high temperatures. So, few char residues are formed above 700 °C for all PEFT blends which is a common phenomenon in most polymer materials . Similarly, the T 5wt% of DOPO–DP is 407 °C, but the T 5wt% of PEFT blends is lower than PEFT, which is similar to the effect in nitrogen.…”

“…Figure presents the 1 H NMR and 31 P NMR spectra of DOPO–DP. The chemical shifts at 7.12–8.23 ppm is the characteristic response for the benzene of DOPO–DP in 1 H NMR . As shown in Figure b, three intensive and sharp chemical shifts are found in the 31 P NMR spectrum of DOPO–DP.…”

“…A fire retardant DPGE was synthesized by using DPCl and genistein. The blend with 8 wt % DPGE shows a UL-94 V0 level . In this case, the genistein has an effect on the condensed phase, and diphenyl phosphonate may affect the gas phase just like DPOD …”

“…In addition, the plasticizing effect of DOPO–DP may deteriorate the mechanical properties of PEFT. To regulate the mechanical performance of PEFT blends, two coupling agents, triglycidyl isocyanurate (TGIC) and 2,2′-(1,3-phenylene)-dioxazoline (PBO), were incorporated into PEFT/DOPO–DP. − Fire-retardant mode of actions for DOPO–DP in PEFT were investigated using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analysis (TGA-Fourier transform infrared spectroscopy (TG-FTIR).…”