A key role of a bio‐based charring‐coupling agent in flame retardant and anti‐dripping performance of polyamide 6/aluminum diethylphosphinate

Abstract

In this work, an organophosphorus flame retardant (BHD) was synthesized using 4‐formylphenylboronic acid and 1,6‐hexanediamine; a charring‐coupling agent containing epoxy (DE) was synthesized using daidzein and epichlorohydrin. The BHD and DE were reacted and coated on the surface of aluminum diethylphosphinate (ADP) and the product is identified as BD‐ADP. PA6 with 12 wt% BD‐ADP achieves a UL‐94 V‐0 rating and a limiting oxygen index (LOI) value of 30.0 vol%. Substitute 1.0 wt% DE for BD‐ADP, PA6‐1.0E not only achieves a UL‐94 V‐0 rating, but also goes out before dripping. The time to ignition of PA6‐1.0E is 19 s longer than that of PA6. The flame‐retardant mode is the combination of the gas‐phase effect of ADP and the condensed‐phase effect of DE. In addition, the tensile strength and impact strength of PA6‐1.0E are 103.9 MPa and 6.6 kJ/m2 which are 35.6% and 43.5% more than that of PA6‐12A. Both BD coating and DE contribute to a strong interfacial adhesion between ADP and PA6 which improves the mechanical properties. The DE plays a key role in the flame retardancy and mechanical properties of PA6 blends.

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

“…PBO has a small effect on TSP, while TGIC decreases TSP slightly. The increase in smoke is related to the scavenging of free radicals in the gas phase, and many flame retardants with strong gas-phase effects lead to an increase in smoke release. , Because after scavenging free radicals in the gas phase, the size of formed char particles is too small to deposit in the condensed phase, and they will evaporate into the air to form smoke. At the same time, DOPO–DP has a good charring ability; therefore, the HRR can be reduced.…”

“…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).…”

Scalable Synthesis of Thymol-Based Bisphenol E Epoxy Monomer and Related Thermosets with Low Dielectric Constant and Density and Improved Resistance to Hygrothermal Aging

“…Toward sustainable epoxy chemistry and technology, research on biobased epoxies has achieved significant progress in recent years. , In particular, exploiting biobased bisphenol alternatives for BPA will play a key role in promoting the sustainability of epoxies in the future. As shown in Scheme S1, a few naturally occurring bisphenols or diphenols bearing two phenolic hydroxyl groups including magnolol, − protocatechuic acid, , catechin, daidzein, − etc. have been directly used to synthesize various curable epoxies by reacting with ECH.…”