Phosphorylated silica/polyamide 6 nanocomposites synthesis by in situ sol–gel method in molten conditions: Impact on the fire-retardancy

Effect of phosphorous-modified silica on the flame retardancy of polypropylene based nanocomposites

“…4b two additional signals at À60 and À69 ppm are detected. They are assigned to the condensed species derived from SiP, T 2 ((SieO) 2 eSi(OR)eR) and T 3 ((SieO) 3 eSieR) respectively [43]. Their low intensities are also in agreement with the low SiP concentration grafted onto the silica.…”

“…The first peak is characteristic of the phosphonate function of the SiP precursor. The second small peak is assigned to the condensed species of the phosphonate function of SiP from literature data [43,44]. It was explained that when PO(OH) 3 condenses to form PO(OH) 2 -O-PO(OH) 2 , a shift in the 31 P peak position from À11 ppm to 24 ppm is observed.…”

“…Indeed, the temperature of pMLR for PP-Tm-10% and PP-Zm-10% increases of about 10 C compared to pure PP but both composites start to decompose at lower temperature, 370 C and 380 C respectively. This very slight decrease of the initial degradation temperature may be assigned to the weak energy of PeC and PeO bonds [43]. Moreover it should be noted that PP decomposes completely at about 475 C. The amount of residue for the composites is respectively 8 wt%, 8 wt%, 6.5 wt% and 5 wt% for PP-T-10%, PP-Z-10%, PPTm-10% and PP-Zm-10% which corresponds roughly to the initial loading of filler and indicates that no char was formed.…”

Influence of organophosphorous silica precursor on the thermal and fire behaviour of a PA66/PA6 copolymer

“…Few years ago, a new approach was developed as an alternative to this path of dispersion [20][21][22] and lately for improving the flame retardancy of thermoplastic polymers such as PA6 [23].…”

“…[23] shows that in situ generation of phosphorylated silica by sol-gel method within a PA6 matrix in the molten state during extrusion is a very novel route for obtaining flame retarded nanocomposites. Results have shown a significant decrease M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 about 50% of the heat of release rate and the formation of an important residue during cone calorimeter test with the addition of only 2.51%wt of silicon and 2.46%wt of phosphorus.…”