Gilbert Clouet

Investigation of some intrinsic parameters influencing the flammability of ω or α, ωphosphonated polystyrenes (III)

SummaryThis paper concerns the study of some chemical intrinsic parameters governing the fire retardant properties of polystyrenes carrying phosphorus atoms at one or both ends of their macromolecular chain. It is shown that their low flammability, depends on the presence of labile atoms, bonded, either directly to the phosphorus atom or in the α position to the phosphorus atom.

Thermal decomposition of 4,4′-azobis(4-cyanopentanol)

SummarySeveral workers (Reed, 1971, 1972, Goldfein, 1975, Kartavykh, 1977) have employed the 4.4′-azobis(4-cyanopentanol) (ACP) as the initiator for the radical polymerization of butadiene, isoprene or acrylic monomers. Nevertheless, the decomposition of (ACP) has never been studied, only the rate constant of decomposition (kd) of (ACP) at 70 °C in acetone has been determined.The present paper reports the kinetics of the thermal decomposition of (ACP): the rate constant of decomposition (kd) at various temperatures and the activation energy of decomposition are determined in dimethyl sulfoxide.

Structure flammability relationships of phosphorus containing polystyrene samples (I)

SummaryPhosphonated polystyrene flammability is discussed in relation to their structure. It is shown that the oxygen Index of phosphonated polystyrenes depends mainly on the position of the phosphorus atoms on the backbone of the polymer and not on the absolute phosphorus content.

Effect of free radicals generating compounds towards the flammability of w-phosphonated polystyrenes — V

SummaryEffect of some free-radicals generating compounds, such as organic peroxides, hydroperoxides and polysulfides, on the Oxygen Index of end phosphonated polystyrenes is investigated. It is shown that some combinations of end phosphonated polystyrene with free-radicals initiators, may be said to have a synergestic effect on flame-retardant properties of standard polystyrene.

Kinetics of the polymerization of methylmethacrylate with 4,4′-azobis (4-cyanopentanol) as initiator

SummaryThe radical polymerization in bulk of methylmethacrylate in presence of 4,4′ azobis(cyanopentanol) (ACP) has been studied at 60°, 67°, 72°, 81° and 84°C. The ratio kp/kt1/2 has been determined for each of these temperatures, using the molecular weight method. The rates constants of decomposition and the efficiency of (ACP) were calculated from conversion-time curves. The activation energy of the polymerization was obtained from the slope of Arrhenius plot of Rp.

Phase separation of phosphonated polystyrenes in the solid state: 4. Influence of this phenomenon on their flame retardency properties

SummaryThe goal of this is to point out, using the Electron Spectroscopy for Chemical Analysis (ESCA) method, that the repartition of phosphorus atoms of phosphonated telechelic polystyrenes in the solid state, is not homogeneous. On the other hand, a correlation is established between the P/C ratio in a thin superficial layer of the polymer and his flammability data.