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Flame retarded thermoplastic polymer compounds were prepared containing recycled rubber tyres, low density polyethylene, ethylene vinyl acetate copolymer and an intumescent additive system consisting of waste polyurethane foam and ammonium polyphosphate. The effect of the additives on the combustion properties was characterised by Limiting Oxygen Index, UL 94 and mass loss calorimetric measurements. The environmental impact was estimated by determining the gas components of CO2 and CO evolving from the compounds during the burning process using a gas analyser system constructed by coupling an FTIR unit to a mass loss calorimeter. The new material forms a thermoplastic rubber of excel- lent processability making it suitable for application in construction industry.

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.

Controlled release formulations of thermoplastic starch (TPS) matrix were prepared by extrusion granulation and injection molding of tablets. The compositions contained glycerol, water and on occasion urea plasticizers, glycerol-monostearate; Ca-stearate lubricants and Na-benzoate drug representing component, in addition to the starch. The lubricants and especially the urea reduce the complex viscosity of the TPS considerably facilitating the injection molding process-ability. DSC thermal analysis demonstrated, the urea is in a molecular dispersed form in the extruded granules and Raman microscopic mapping showed an under micron sized dispersion of Na-benzoate in injection molded tablets. Both the extrusion and the injection molding processing resulted retard release character of the active component.

The effects of non-treated (MMT), organophilic (OMM), and olefin/silicone polymer intercalated (IMM) montmorillonites on the thermal stability of ethylene–vinyl acetate copolymer (EVA) and on the flammability of magnesium hydroxide filled EVA were studied. The influence of various treatments on the delamination of montmorillonites in EVA was detected by rheological measurements and by Raman microscopy. The latter was a unique method for rapid detection of the dispersion also in highly filled EVA. Enhancement of thermo-oxidative stability of EVA and flame-retarded EVA could be observed by thermal analysis in the presence of variously treated montmorillonites. The flame-retardant efficiency of magnesium hydroxide was improved by simultaneous application of MMT and IMM. The increased performance of magnesium hydroxide was explained by the rheological effect of the IMM, catalytic effect of MMT and chemical interactions of montmorillonites with the metal hydroxide.

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.

In this work we aimed at forming partially recycled polymer composites of appropriate mechanical properties and flame retardancy. Multilayer composite structures proved to be suitable to fulfill all of these requirements. Core-shell structures presented here contain two-component thermosets, i.e. epoxy, recycled polyurethane and polyisocyanurate, as matrices reinforced with waste fillers such as short basalt fibers and wood chips. Flame retardancy and mechanical properties of the core-shell structures were investigated by the conventional methods of characterization. The developed cost-effective multilayer composites can be applied as heat and sound insulating panels e.g. multifunctional sheets for construction or automotive industry.

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.

Interface modifications optimized for fire retardancy require detailed research. Confocal Raman microscopy was used to analyze the degradation locally in the area of the nanotube and clay additives. The double-walled carbon nanotube (DWCNT), containing Co catalyst residue, accelerates the deacetylation process of poly(ethylene-co-vinylacetate) (EVA) considerably, while the montmorillonite (MMT) has no significant influence under static circumstances. The compounding process influences the effect of MMT, which causes partial crosslinking in EVA during the compounding. This mechanochemical reaction is catalyzed by uncovered MMT particles, while organophillized MMT promotes the charring process. Inorganic surface modification with various metal ions has also some stabilizing effect. Spray drying of MMT results in microparticles of increased surface area and improved thermal stability of the EVA system. The lowest rate of flame spreading was achieved using uncoated MMT, while coating with cationic surfactant was most efficient for hindering dripping. The rate of heat release (RHR) of the organically modified and the spray dried MMT was approximately the same. The combined organic-inorganic modified clay moderates both the dripping and the flame spreading in the EVA. Copyright © 2006 John Wiley & Sons, Ltd.

Simple method is proposed for in situ formation of nanodispersion through computer-controlled emulsion polymerization. The method is based on the application of cationic emulsifier during polymerization, which performs cation exchange with the surface Na ions of montmorillonite nanoparticles. The endpoint of polymerization is detected by Raman microscopy while the structure is determined by atomic force microscopy. The nanodispersion is used in the tablet-coating process. Raman microscopy provides a new non-destructive way for controlling the thickness and uniformity of the coatings during the procedure, while the surface defects can be determined by atomic force microscopy. © 2006 John Wiley & Sons, Ltd.

Common consideration and classification of surface and interface phenomena in wide areas of material science are discussed through three examples: basalt fiber reinforced composite; flame retarded polypropylene and polyorganosiloxane nanocomposite. Interface-related characteristics of polymer composites and biomaterials are discussed using uniform principles. A new classification of the interphases is introduced including the compatible, adaptive and smart interfacial layers. In case of basalt fiber reinforced polypropylene reactive interface modification is performed in a new and economic way using reactive surfactants. These additives accomplish the compatibilization of the phases during reactive compounding/processing. The fire retardancy of polypropylene system containing ammonium polyphosphate and clay nanoparticles is enhanced by adaptive polysiloxane interphase. Clay additive provides thermal and pH responsive character to silicone based biomaterial thus it can be applied for forming smart interphases.

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 deterioration of naturally aged low-density polyethylene (LDPE) film was observed by elongation properties, DSC melting enthalpies and surface geometric characteristics by use of atomic force microscopy (AFM). The decrease of elongation at break under the influence of ageing was in good accordance with the increase of melting enthalpies and both phenomena could be explained by the gradual decrease of molecular mass of the polymer. On the wavy surface with a wavelength range of 10–15 μm, valleys with amplitudes from 160 to 600 nm could be observed by AFM depending on the time of ageing. The increase of deepness of valleys was explained not by the gradual erosion of the degraded surface but by the gradual increase of crystallinity, consequently the gradual shrinking on the surface of the polymer film. The gradual increase of crystallinity in the surface region of the film could be demonstrated by confocal Raman microscopy.

This work deals with the effect of recycling on halogen-free flame retarded polypropylene blends. The intumescent ammonium polyphosphate/polyamide-6/polypropylene blend is considered. The study of the fire properties using cone calorimeter shows a decrease in the fire performance. Recycling the blends induces chemical modifications of polymer and additives. The chemical modifications due to the recycling are investigated by solid state31P NMR. It is shown that APP is degraded. These modifications induce a loss of the ammonium contents, which could explain the decrease in the fire performance.

Multilayer systems consisting of flame retarded and reinforced layers of recycled polymer were formed. The structure and the thickness of the interfacial layer between the phases were analysed by Differential Scanning Calorimetry and Raman microscopy. The sequence order of the layers was varied for achieving improvement in both the flame retardancy and mechanical performance of recycled polymers and for obtaining upcycled product this way. Investigation of injection moulded and compression moulded products demonstrated the advantage of reinforced core and flame retarded shell over the opposite structure. The multilayered structure was found an economic way for producing recycled polymer materials of improved fire resistance, flexural strength and modulus.

A series of two-component powders and tableted mixtures of corn starch and lactose-monohydrate were prepared and studied using the fiber optic sensor of a LabRam dispersion Raman microscope in order to establish a convenient method for quantitative determination of their concentration based on Raman spectra. The intensities of certain characteristic peaks of the components were used for calculating the calibration curve. Linear calibration curves were found in the concentration range of 10–80% with correlation coefficients of 0.9979–0.9996 for powders and tablets. Chemical mapping of the tablets was also carried out, thus allowing determination of the distribution of the components. Copyright 2003 John Wiley & Sons, Ltd.

Basalt fibers, similarly to other silicate fibers, can be introduced into both thermoplastic and thermosetting polymer matrices. In this work some basalt fiber reinforced polypropylene composites were investigated. The fiber-matrix adhesion was improved by commercial and non-commercial maleic anhydride derivatives. The latter types, called reactive surfactants, were prepared in laboratory scale and the progress of the syntheses was determined by Raman microscopy. The additives allowed performing reactive interface modification during the compounding process. Due to the interface modification with the additives in low concentration the mechanical properties improved. The boundary layers on the surface of the reinforcing fibers were observed using scanning electron microscopy (SEM).

The Raman microscope is one of the most convenient instruments for analyzing the structural characteristics and changes in the interfacial region of multicomponent systems. This is confirmed by the results obtained in the field of packaging materials, nanocomposites, and basalt fibre reinforced composites. In the course of this study, the chemical character of the surface and interfacial regions were investigated and, in addition, the local characteristics of the crystallization process of the polymer matrix could be determined.

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.

The principle of multilayer interphases was proposed earlier for modifying the mechanical properties and UV stability of various multicomponent polymer systems. This paper focuses on the applicability of this principle for improving the performance of intumescent flame-retardant systems using melamine-treated ammonium polyphosphate, silicone modified polyol + ammonium polyphosphate, and silicone modified nanoparticles in polypropylene. The structure–property relationship of the formed systems was studied. A melamine layer of 1.45 nm thickness was formed around ammonium polyphosphate in order to improve the hygrothermal stability, but this layer was not shear-resistant enough. An interphase formed using a special silicone additive is more stable and acts with the intumescent flame-retardant system synergistically. The advantageous interfacial structure is quite complex in this case: polyphosphate particles are surrounded with a macromolecular layer formed from polyol, silicone, and reactive surfactant in order to ensure good stability, efficiency and compatibility. AFM, XPS and a Cone Calorimeter were used for determining the structure and flame-retardancy of these systems. Nanocomposites combined with silicone-containing intumescent system were developed in order to avoid dipping at ignition in the vertical position. SAXS and µ-TA methods were used for determining the structure of this material. Copyright ­© 2003 John Wiley & Sons, Ltd.

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.

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.

The deterioration of differently stabilised and pigmented high density polyethylene films was investigated by DSC and UV spectroscopy methods in the course of accelerated photo-ageing and compared to earlier XPS and gel-content results. Unexpectedly quick destruction of phthalocyanine containing film was observed and explained by the adsorptive removal of the stabiliser from the polymer matrix. In the pigment (filler)-solvent-stabiliser model systems the high susceptibility of hindered phenol type heat-stabiliser to adsorb on talc and phthalocyanine pigment was proved by UV spectroscopic measurements. Surface coating of the talc and pigment with a reactive surfactant considerable reduced the adsorption capacity and thus improved the photo-stability of the pigmented film.

A mechanistic scheme is suggested for lactam polymerisation initiated by hydrochloric acid on the basis of the general mechanism put forward earlier by Bertalan et al. According to this mechanism during the polymerization conditions are created which can initiate further polymerizations resulting in a characteristic inflection type kinetic curve. Experimental results can be well interpreted qualitatively on the basis of this mechanism, and therefore it can serve as a starting point also for a quantitative kinetic model.

A quantitative description of the hydrochloric acid initiated polymerization of caprolactam (CL) based on the previously proposed mechanism is given. Essential parameters were identified by strategy mainly based on principal component analysis. Our kinetic model is in good agreement with experiments and describes specific features of the kinetics of the process with the suggested parameters.

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.

Entsprechend dem von den Verfassern vorgeschlagenen Kettenwachstumsmechanismus sind bei der mit Aminsalzen initiierten kationischen Lactampolymerisation nicht nur Ammonium-, sondern auch Amidin-Endgruppen vorhanden. Es wurde eine Methode zur Bestimmung der beiden basischen Endgruppen nebeneinander ausgearbeitet. Zunachst wird die Gesamtkonzentration aller basischen Endgruppen durch potentiometrische Titration mit Perchlorsaure in nichtwasrigem Medium bestimmt. In einer anderen Probe werden die Amino-Endgruppen mit Essigsaureanhydrid acetyliert und die unverandert gebliebenen Amidin-Endgruppen auf die gleiche Weise titriert. Die Konzentration beider Endgruppen andert sich im Laufe der Polymerisation in Abhangigkeit von der Temperatur und der Initiatorkonzentration charakteristisch. Die Gesamtbasizitat nimmt in jedem Fall auf Grund hydrolytischer Prozesse zu, die durch die Einwirkung des wahrend der Amidinbildung entstandenen Wassers ablaufen. Die Konzentration der Ammonium-Endgruppen nimmt in jedem Fall in Abhangigkeit von der Temperatur und der Konzentrationen des Initiators ab, die Konzentration der Amidingruppen andert sich in entgegengesetzter Richtung. Die Anderung der Endgruppenkonzentration ist mit den kinetischen Kurven der Polymerisation und dem vorgeschlagenen Wachstumsmechanismus in gutem Einklang. Beim Auftreten eines Wendepunkts entspricht dieser den Extremwerten der Endgruppenkonzentrationen. According to the chain growth reaction mechanism formerly proposed by the authors for cationic lactam polymerization initiated by amine salts not only ammonium but also amidine end-groups are present. A method has been worked out for simultaneous determination of the two different end-groups. In non-aqueous media titrating with perchloric acid first the total concentration of the two basic end-groups is determined potentiometrically. After acylation of the amino end-groups by acetic anhydride in another sample the amidine end-groups are titrated as before. The concentration of the two different basic endgroups change, during polymerization, characteristically depending on the temperature and the concentration of the initiator. The total basicity increases in all cases owing to the fact that water produced during amidine formation generates hydrolytic processes. The ammonium-group concentration decreases in all cases depending on the temperature and the concentration of the applied amine salt initiator. The amidine-group concentration changes in opposite direction. Changes in the end-group concentration can be well brought into accord with the kinetic curves and the proposed chain growth mechanism of the polymerization. In case of inflexional kinetics the point of inflexion of the kinetic curve coincides with the extreme values of the end-group concentration.