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

Abstract

International audienceSurface modification of various silicas by phosphorous agents was carried out with the aim to use these particles as flame retardant additive in a polypropylene matrice (PP) at low content (10 wt%). Thermal and flammability properties of PP/modified silica (PP-Tm-10%, PP-Zm-10%) were studied using TGA, PCFC and cone calorimeter and compared to those conferred by pure silica (PP-T-10%, PP-Z-10%). Quite surprisingly the untreated fillers induce the most significant reduction of peak of Heat Release Rate (50% decrease) while the surface modification by phosphorous agents does not lead to the expected effect on the fire behavior of PP composite. This phenomenon was related to the morphology and rheological behavior of the various PP composites. Indeed, the higher the storage modulus at low frequencies is, the better the fire behavior is, because of the induced barrier effect. Moreover, the addition of non modified silicas leads to a decrease of 10 s of the TTI. This phenomenon was related to the formation of bubbles after the PP melting during cone calorimeter test

Synergistic effect of phosphorus‐containing silane coupling agent with alumina trihydrate in ethylene‐vinyl acetate composites

“…This is related to the dispersity of ATH in EVA matrix and has been limitedly improved by adding DOSA directly. Moreover, the synergistic flame‐retardant mechanism of ATH and DOSA which contain phosphor and silicon element plays an important role in the improvement of LOI value . The LOI value of EVA/DIATH composites with 50% DOSA‐immobilized ATH is 31.4 which will meet the requirement of flame retardancy in the electronic appliance.…”

Synergistic effect of cocondensed nanosilica in intumescent flame‐retardant polypropylene

“…The 13 C NMR spectrum of SiO 2 -NH 2 is showed in Figure 3. During the process of cocondensation, TEOS and APTES are both involved in the buildup of the gel network.…”

“…The most widely used strategy is to introduce organic functional groups. Studies have shown that surface organic modification of the nanoparticles can effectively improve the flame‐retardant efficiency, but the processes of modification are usually solvent‐wasted, and the amount of introduced organic groups is limited. Cocondensation method is a kind of sol‐gel process utilizing organosiloxanes as a comonomer to hydrolyze and cocondense with tetraethylorthosilicate (TEOS) .…”

The influence of mesoporous silica modified with phosphorus and nitrogen‐containing hyperbranched molecules on thermal stability, combustion behavior, and toxic volatiles of epoxy resin

“…Moreover, nitrogen‐containing flame retardants can produce non‐flammable non‐toxic gases, thus diluting the oxygen near the flame and inhibiting combustion . Previous researches have demonstrated that flame retardants containing Si, P, and N co‐elements can exhibit the better flame‐retardant efficiency than flame retardants containing P, N, or Si alone . Thus, it is anticipated that mesoporous silica modificated with organic flame retardants consisting of P, N elements could offer better flame retardant properties to inflammable EP.…”

“…than flame retardants containing P, N, or Si alone. [22][23][24][25][26] Thus, it is anticipated that mesoporous silica modificated with organic flame retardants consisting of P, N elements could offer better flame retardant properties to inflammable EP.…”