Here we report the preparation and characterization of the new diphosphonium-MMT(DP-MMT) by the intercalation of the quaternary diphosphonium salt [MeOOCCH2(Ph)2PCH2CH2P(Ph)2CH2COOMe]Br2 (DP) with the aim to use it in the preparation of polyurethane foam-nanocomposites [1]. DP-MMT was completely characterized by multinuclear NMR in the solid state (Figures 1 and 2). Mono- and bisphosphonium salts are already used as flame retardants for textiles and paper as well as heat stabilizers for nylon. The use of phosphonium salts as organic modifiers to layered silicates may further enhance the thermal stability and flammability properties of polyurethane nanocomposites. The presence of two phosphorus atoms in the diphosphonium molecule, together with the carbonyl moieties suitable for interactions and compatibilization with the polyurethane chain and the possibility to use smaller amounts of additives in nanocomposites, make in principle DP-MMT a promising additive fire retardant for polyurethane rigid foam (PUR) [2]. Foams were prepared using a two step procedure. In the first step a fixed amount of clay (5wt% on total foam mass), which was previously dehydrated overnight at 110°C, was dispersed in polyols mixture. In order to promote clay dispersion microwave treatments were used [3,4]. TEM analyses showed that DP-MMT and HPS contained foams stack of platelets. Thus, in principle, phosphonium systems can be tailored in order to optimize interaction with the aluminosilicate layer with the aim to favour the formation of stable compounds and improve thermal stability of the nanocomposite . Unprecedented MMT modified with fluorinated ammonium salts of the type [RFCH(OH)CH2NR2]+X- (RF-MMT)have been prepared. XRD data indicate a significant increase of the basal spacing to ca . 3 nm. The influence of the presence of RF-MMT on surface and thermal properties of nanocomposites is under investigation. Preliminar results on LDPE-nanocomposites are reported.

Preparation and characterization of organoclay polyurethane nanocomposites

ZAGGIA, ALESSANDRO;LORENZETTI, ALESSANDRA;MODESTI, MICHELE;CONTE, LINO;BERTANI, ROBERTA
2009

Abstract

Here we report the preparation and characterization of the new diphosphonium-MMT(DP-MMT) by the intercalation of the quaternary diphosphonium salt [MeOOCCH2(Ph)2PCH2CH2P(Ph)2CH2COOMe]Br2 (DP) with the aim to use it in the preparation of polyurethane foam-nanocomposites [1]. DP-MMT was completely characterized by multinuclear NMR in the solid state (Figures 1 and 2). Mono- and bisphosphonium salts are already used as flame retardants for textiles and paper as well as heat stabilizers for nylon. The use of phosphonium salts as organic modifiers to layered silicates may further enhance the thermal stability and flammability properties of polyurethane nanocomposites. The presence of two phosphorus atoms in the diphosphonium molecule, together with the carbonyl moieties suitable for interactions and compatibilization with the polyurethane chain and the possibility to use smaller amounts of additives in nanocomposites, make in principle DP-MMT a promising additive fire retardant for polyurethane rigid foam (PUR) [2]. Foams were prepared using a two step procedure. In the first step a fixed amount of clay (5wt% on total foam mass), which was previously dehydrated overnight at 110°C, was dispersed in polyols mixture. In order to promote clay dispersion microwave treatments were used [3,4]. TEM analyses showed that DP-MMT and HPS contained foams stack of platelets. Thus, in principle, phosphonium systems can be tailored in order to optimize interaction with the aluminosilicate layer with the aim to favour the formation of stable compounds and improve thermal stability of the nanocomposite . Unprecedented MMT modified with fluorinated ammonium salts of the type [RFCH(OH)CH2NR2]+X- (RF-MMT)have been prepared. XRD data indicate a significant increase of the basal spacing to ca . 3 nm. The influence of the presence of RF-MMT on surface and thermal properties of nanocomposites is under investigation. Preliminar results on LDPE-nanocomposites are reported.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2515327
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