Synthesis of a new organophosphorous alkoxysilane precursor and its effect on the thermal and fire behavior of a PA66/PA6 copolymer

Abstract

Authors would like to thank Christine LUCAS for help in solid state NMR experiments, C2P2 (Chemistry, Catalysis, Polymer & Processes), UMR 5265 - University of Lyon 1.International audienceA new silicophosphorylated filler was generated in situ in a molten PA66 copolymer during extrusion process with the aim to improve the fire behavior of the matrix. The filler was obtained in one step via hydrolysis-condensation reactions of SiDOPO precursor (DOPO, 9,10-dihydro-9-oxa-10-phosphaphenanthrene). The synthesis of the precursor is reported and characterized by NMR. A Si-29 NMR study of SiDOPO hydrolysis-condensation reactions in N-methylacetamide (NMA) solvent was also conducted. Thermal stability of Cop-PA/SiDOPO composite and the major degradation products were studied by thermogravimetric analysis coupled with Infrared spectrometry (TGA/FTIR). The Pyrolysis Combustion Flow Calorimeter (PCFC) and cone calorimeter were used to investigate the fire behavior of the composite. Results show that the nanocomposite exhibits a little earlier ignition but with a decrease around 33% of the peak of heat release rate (PHRR). The presence at low concentration of silicon (0.65 wt.%) and phosphorus (0.75 wt.%) promotes the formation of an expanded char layer that acts as a barrier. A reduction of about 18% in effective heat of combustion (EHC) values suggests an additional flame inhibition effect of phosphorus in the gas phase

Flame retarded polyamide-6 composites via in situ polymerization of caprolactam with perylene-3,4,9,10-tetracarboxylic dianhydride

“…PTCDA obviously reduces the rate of decomposition of the composite. These results indicate that PTCDA plays a role in the condensed phase [22]. The total heat release is one of the most important parameters to evaluate flame-retardant materials.…”

Halogen-free flame retardants for application in thermoplastics based on condensation polymers

“…A proportion of 20% OP was enough to achieve the V-0 rating. In the same type of polyamide, but containing HNTs and OP1312, an improvement in mechanical, thermal and flame retarding [104] properties has been observed by using a minimum concentration of 25% FR and 2.5% NPs [109]. By modifying the alkyl structure of the phosphinates, different fire retarding effects can be obtained on the polymer they are loaded in.…”

“…The LOI attained 31% and the char residue increased to 11.6% when DOPO-SiO 2 and Review Paper OP1314 were used. In the PA66 copolymer, DOPO-SiO 2 precursor decreased the pHRR by 33%, while the effective heat of combustion (EHC) was reduced by 18% [104]. The chain extension with a DOPO-based diepoxide compound (DEP) is another method to enhance FR properties of PA6 [105].…”

Recent Advances in Production of Flame Retardant Polyamide 6 Filament Yarns

“…Th is promotes the formation of a closed char layer. 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10oxide-based diepoxide (DEP) [34,35] cyclotriphosphazene [36][37][38] Phosphorous, aluminium aluminium dialkylphosphinate (AlPi) [16, 28-31, 33, [38-46] aluminium hypophosphite [41,42,47] Phosphorous, boron boron phosphate [44,48,49] Phosphorous, silicon 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10oxide-functionalised triethoxysilane (SiDOPO) [50,51] diethylphosphatoethyltriethoxysilane (SiP) 52 MPP, as a representative of the P/N-based FR additives, was developed as a char former in the intumescent FR action. Th e latter is characterised by swelling and expanding at temperatures higher than critical temperature, leading to the formation of a foamed cellular charred layer [4,9,69].…”