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The flame retardant effect of newly synthesized phosphorus-containing reactive amine, which can be used both as crosslinking agent in epoxy resins and as a flame retardant, was investigated. The effect of montmorillonite and sepiolite additives on the fire induced degradation was compared to pristine epoxy resin. The effect of combining the organophosphorous amine with clay minerals was also studied. It could be concluded that the synthesized phosphorus-containing amine, TEDAP can substitute the traditional epoxy resin curing agents providing additionally excellent flame retardancy: the epoxy resins flame retarded this way reach 960 °C GWFI value, 33 LOI value and V-0 UL-94 rating – compared to the 550 °C GWFI value, 21 LOI value and “no rate” UL-94 classification of the reference epoxy resin. The peak of heat release was reduced to 1/10 compared to non-flame retarded resin, furthermore a shift in time was observed, which increases the time to escape in case of fire. The flame retardant performance can be further improved by incorporating clay additives: the LOI and the HRR results showed that the optimum of flame retardant effect of clay additives is around 1 mass% filler level in AH-16–TEDAP system. Applying a complex method for mechanical and structural characterization of the intumescent char it was determined that the flame retarded system forms significantly more and stronger char of better uniformity with smaller average bubble size. Incorporation of clay additives (owing to their bubble nucleating activity) results in further decrease in average bubble diameter.

Methods are proposed to synthesize efficient organophosphorous compounds and combine them with montmorillonite nanoparticles. The chemical–physical structure and mechanism of action of the new systems were studied in epoxy resin. Best results were achieved using the fully phosphorylated calixresorcinarene derivative: the heat release rate peak could be decreased by 61% and the LOI value was increased from 21 to 28. The salt form of additives in case of phosphorylated phloroglucine derivatives was not advantageous in epoxy resin, because the additives could not participate in the crosslinking process effectively due to their inhomogenous distribution in the matrix. The incorporation of the nanoparticles did not create the desired flame retardant effect which can be explained by the increased heat conductivity and lower mobility of the nanoparticles due to the crosslinked structure.

Flame retardant effect of newly synthesized phosphorus-containing reactive amine, which can be used both as crosslinking agent in epoxy resins and as flame retardant, was explored. The effect of montmorillonite and sepiolite additives on thermal stability and flame retardancy was compared in the epoxy resin matrix. Copyright © 2006 John Wiley & Sons, Ltd.

The efficiency of ammonium polyphosphate in different biocomposites was compared. For the comparison flame retarded lignocellulosic filler reinforced biocomposites were prepared using polypropylene (PP), polyurethane (PUR) and fully biodegradable starch matrices. The compatibility of wood flake with PP was improved by application of an alkoxy silane based reactive surfactant. The silylation improved not only the compatibility but also the thermal stability of the wood flake according to TG measurements. Raman spectroscopic analysis of the silylated product showed that the improved thermal stability is the result of reduced ratio of the amorphous phase of cellulose. The phosphorus additives in flame retarded PUR biocomposites, comprising waste bio fillers and recycled polyol, proved to be very effective because both the matrix and the filler components participate in mechanism of flame retardancy. Plasticised thermoplastic starch could be flame retarded efficiently by as little as 10% ammonium polyphosphate. After their service life the biocomposites can be utilised as chemical fertilizer.

The first part of this work deals with the effect of ageing (artificial weathering) on an intumescent flame-retarded ammonium polyphosphate (APP)/polyamide-6 (PA-6)/polypropylene (PP) blend. The study of the fire properties using the cone calorimeter shows a decrease in the performance caused by the artificial weathering. The chemical modifications of the blends after ageing are investigated by solid state 31P NMR and SEM. It is shown that APP is degraded into ortho-, pyrophosphate and short chain polyphosphates. These modifications lead to the loss of the ammonium contents which could explain the decrease of fire performance. Moreover, some morphological changes appear which may lead to the change of fire and mechanical properties. A classical solution for re-using the material is the recycling. In the second part of this study, we examine the effect of recycling simulated by a multi-extrusion process. This treatment induces modifications which are different from those resulting from the effect of ageing. So, morphological and chemical changes induced by recycling are compared to the effects of ageing. It is shown that after recycling APP is also degraded in the same way as after ageing. In addition to the degradation of APP, a decrease in phosphorous concentration is observed which is attributed to the migration of phosphate species.

Polypropylene-based composites were prepared containing non-treated and various treated cotton fibre and wood flakes. A correlation was observed among the fibre treatment and compounding parameters, mechanical and discoloration properties. The structural changes in fibres were demonstrated by Raman spectroscopic and DSC measurements. The possibility for forming cellulose fibre containing flame retardant composites was also investigated. The efficiency of various treatments on compounding, discoloration and mechanical properties enhance in the following order: no treatment < non ionic surfactant < reactive silicone segment containing non ionic surfactant < special silylation treatment. The best results obtained with the special silylation treatment were explained with the more organophilic character and by the thermal stability of the treated fibres. Cellulose fibre as a polyol-charring component and ammonium-polyphosphate together constitute a high performance intumescent flame retardant system in the PP matrix.

Flame retarded polyethylene compounds were prepared using a series of aluminium hydroxide of different particle size applying a milling processes and special precipitation technologies. The processability and flame retardant efficiency of the flame retarded systems were compared. The effects of various surface modifications were analysed in case of one selected type of aluminium hydroxide. A silicone terminated reactive surfactant promoted not only the processability but also the flame retardant efficiency. Noise damping sheets were prepared by simultaneous application of aluminium hydroxide and barium sulphate in an elastomer blend matrix. V0 flame retardant grade could be achieved this way accompanied with improvement in the acoustic properties and maintenance of the mechanical properties.

Addition of Ammonium Polyphosphate/Polyamide-6 system is known to provide flame retardancy in many polymers blends via an intumescent process. Particulate fillers (talc and calcium carbonate) are used in large quantities in PP. Combination of fillers in PP can modify the properties of the polymeric matrix. This study investigates the effect of fillers (talc and calcium carbonate) on the fire performance of the Polypropylene/Ammonium polyphosphate/Polyamide-6 blend. It is shown that the fire performance strongly depends on the nature of the filler used. Talc increases and calcium carbonate decreases in the fire performance of the blend.

Monophosphorylated hydroxy phenols were synthesized in a selective way and incorporated in different percentages into epoxy resins as reactive flame retardants. The LOI values of the epoxy resin samples could be increased this way up to 28%. The DSC results show that by increasing the percentage of incorporated monophosphorylated hydroquinone (HMP), the exothermic effect of the curing is decreased, which implies lower network density. An optimum balance is necessary between the flame retardant effect, determined by percentage of HMP, and the lower degree of crosslinking.

Mg(OH)2 and ammonium polyphosphate (APP) based flame retarded polyethylene (PE) and polypropylene (PP) compounds were prepared in a plastograph and the influence of additive systems on the microstructure, mechanical, and melt characteristics of the compounds was investigated by DSC, Raman microscopy, and rheological measurements. A high loading of Mg(OH)2 has a nucleating and crystallinity reducing effect in low density PE. The crystallinity reducing effect was explained by formation of a partially ordered but noncrystallized interfacial region around the flame retardant (FR) particles. The nucleating effect was hindered when the particles were embedded in elastomer. The nucleating effect of APP in PP was also reduced when a polyol layer surrounded it. The incorporation of boroxo siloxane (BSil) elatomer FR synergist, introduced additionally to the above additives, resulted in a further nucleating effect, and increased the melt viscosity. Polymer layered montmorillonite, applied instead of BSil elastomer,...

A model system of intumescent flame retardants, consisting of ammonium polyphosphate and pentaerythritol was prepared and investigated in polypropylene and without the polymer matrix. Thermal scanning oscillation rheometric investigation in the temperature range of 170–500 °C was used to detect the rheological behaviour in the region of melting of the polymer and the plasticity of the char formed at higher temperature. Addition of boroxo siloxane to the model system caused advantageous changes in both regions. Increased complex viscosity and viscoelsasticity of the melt and char respectively contributes to better flame retardancy. According to DTG and FTIR studies the reactions of boroxo siloxane with pentaerythritol and ammonium polyphosphate are the reasons for the rheological changes.

Addition of the ammonium polyphosphate/polyamide-6 blend is known to enable fire properties of interest to be obtained in many polymers. However, the use of an interfacial agent is required to stabilise the formulation. This study investigates the improvement of the fire performance induced by incorporation of ethylene–butyl acrylate–maleic anhydride (EBuAMA) and ethylene vinyl acetate (EVA x , where x is the vinyl acetate weight level) as interfacial agents of the polypropylene/ammonium polyphosphate/polyamide-6 blend. It is shown that the improvement strongly depends upon both the nature and the amount of interfacial agent used.

Boroxo siloxanes were used as a ceramic precursor, combined with an intumescent flame retardant additive system, in polypropylene. Varying the composition and content of the precursor characteristic changes of melt viscosity were detected. Chemical interaction of the additives at the temperature of processing, confirmed using Fourier transformed infrared (FTIR) methods, are related with these rheological changes. Raman microscopic analyses were used to obtain better understanding of the chemical changes of the precursor during flame treatment. Interaction between boroxo siloxane and layered silicate (montmorillonite) nanoparticles was investigated using thermogravimetry.

The fire performance of intumescent PP/APP/PA6/EVA19 blends were previously put forward in part I of this article. In the present part, the thermal and thermo-oxidative degradations of the formulations are modelled. The comparison between the kinetic data determined in this study and data from previous studies suggests that PP degrades before the reaction between APP and PA6. However it may be supposed that in the conditions of a fire (i.e. at high heating rate) both reactions occur simultaneously. Thus the development of an efficient protective structure is possible which could explain the fire properties of interest observed in the conditions of the cone calorimeter.

New reactive additives were synthesised and used as interface modifiers in different multicomponent polyolefine systems. The synthesis was carried out in computer-controlled reactor by means of Diels-Alder reaction and condensation. These additives are capable of combining the benefits of dispersing and coupling agents. A part of the synthesised reactive surfactants have also synergistic effect in flame retardant systems. Their surface-active character facilitates the reactive compounding. The undesirable transport processes of stabilisers and components of flame-retardants in polyolefine systems could be effectively controlled by interface modification.

New reactive surfactants (RS) and synergistic reactive surfactants (SRS), containing reactive groups and longer unsaturated apolar hydrocarbon chains have been synthesised and applied in filled and flame-retarded polymer systems, respectively. These additives are capable of reactions with the polymer matrix and the disperse phase as well. The reaction of these compounds with polyolefins was proven on model system by surface analysis, while their reaction with fillers was demonstrated by DSC. The interface modification in filled/reinforced polymer systems and polymer blends resulted in improved mechanical properties, while in pigmented PE it contributed to higher photostability. Furthermore, the efficiency of intumescent flame retardant additives in polyolefins could be enhanced.

Optimal concentration of boroxo siloxane elastomer synergist was determined by LOI and cone calorimetric measurements on ammonium polyphosphate and pentaerythritol containing intumescent flame retardant for polypropylene. The increased viscosity of the melt and plasticity of intumescent char due to boroxo siloxane elastomer could be proved by a thermal scanning rheometric investigation. It is presumed, the increased melt viscosity is created by the product of boroxo siloxane-pentaerythritol, formed during the compound preparation, while the improved char plasticity is the result of product formed at high temperature from boroxo siloxane and ammonium polyphosphate.

Pentaerythritol may react with tetraethoxy-silane and ammonium-polyphosphate in flame retarded polyolefins and an interfacial layer can be formed around the ammonium-polyphosphate particles. It is advantageous to study such systems using methods of thermal and surface analysis together.

Increased strength, adsorption capacity and improved resistance against a flame of split film polypropylene fibers could be achieved by applying particulate additives with modified interphases. In the presence of an elastomer interlayer a high drawing ratio could be achieved. A reactive surfactant additive was more appropriate for increasing the tensile strength of filled fibers, while oil adsorbent fibers required fillers covered with non-reactive surfactants for improving the adsorption capacity. Model experiments using XPS and DSC methods and SEM analysis were applied for studying the cause of these effects. The migration of flame retardant additives to the surface of PP fibers could be followed using the XPS method. This advantageous effect can be promoted by silicone interphase.

Engineering application of polypropylene requires the employment of flame retardants. Reactive compounding of ammonium-polyphosphate and synergist additives with polypropylene is an effective way for forming flame retardant polypropylene. Both the ammonium-polyphosphate and the additives used for improving its performance effect the crystallization and melting behavior of polypropylene. Encapsulation of flame retardant additives with appropriate elastomer, in order to improve their water resistancy, causes further changes in degree of crystallinity and consequently in the mechanical properties.

Various flame retardant, recycled ground rubber containing compounds were prepared in a polyethylene-ethylene vinyl acetate blend matrix with the help of a reactive surfactant. The beneficial effect of ground rubber was demonstrated on the flame retardancy, noise damping, and environmental impact of the compounds.

Advancement of the methods used to produce fire retardancy is hindered by the shortcomings of the current characterization methods and insufficient understanding of the fire retardancy mechanisms. These two factors are connected with each other: better characterization would promote better understan...

One way to improve the fire performance of polymers is by the development of intumescent systems. The addition of ammonium polyphosphate/polyamide-6 is known to provide flame retardancy in many polymers via an intumescent process. The development of appropriate formulations is limited by their mechanical properties. This study shows that polypropylene based intumescent blends are efficient fire retardant systems and that acceptable mechanical properties can be obtained. It is also shown that adding talc improves the mechanical properties of intumescent polypropylene formulations without decreasing their fire retardancy.