الفهرس 
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Abstract
The aim of this work is to investigating the effect of new intumescent flame retardant compounds (IFRs) on the flammability, thermal stability and toxicity of linear low density polyethylene. The effect of IFRs on the thermal stability and flammability properties of linear low density polyethylene (LLDPE) was studied by thermogravimetric analysis (TGA), vertical burning test (UL-94V), and cone calorimeter. The results showed that addition of IFRs to LLDPE improved the thermal stability at high temperatures and enhanced the char formation at 750 °C. The cone calorimeter data showed that the new IFRs considerably reduced peak of heat release rate (pHRR), mean heat release rate (mHRR), total heat release (THR), and mean mass loss rate (mMLR) of LLDPE. The data of fire performance index (FPI), fire growth rate index (FIGRA), and maximum average rate of heat emission (MARHE) indicated IFRs additives reduced the fire risks and toxicity of LLDPE. The digital photographs, SEM images, and EDXS analysis for the char residue after cone calorimeter test showed the formation of coherent, compact, and thermally stable char layer on the polymer composites surfaces. The results of CC-FTIR showed that the addition of new IFRs into LLDPE reduced the emission of CO and CO2 gases. Also the calculation of FED and LC50 indicated decreasing in the toxicity of the most polymer composites comparing with pure LLDPE.
Keywords:
Intumescent flame retardant (IFR), LLDPE, Toxic gases.
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Summary
Life risk from fires depends upon the probability of fire occurrence and the severity of the fire hazards. Toxic hazards in fires depend upon the mass loss rate of the burning fuel, the yields of toxic combustion products and their effects on exposed subjects. Fire retardant treatment of materials and products provides considerable benefits in terms of fire performance. The principal benefit for most products treated with fire retardants is an improvement of ignition resistance for heat or flame exposures up to a design level of fire intensity or exposure duration, thereby reducing the probability of ignition. Despite these benefits, fire retardant systems show certain limitations. They do not provide non combustibility in a product, but ignition resistance to a design limit. If this limit is exceeded a propagating fire may result, and in some situations rapid fire spread may occur. If a fire does occur (depending upon the fire retardant system used), the yield of common toxic fire gases from the base material [such as carbon monoxide (CO)] may be increased, and the fire retardant may decomposed to release additional toxic products, such as acid gases.
The intumescent flame retardant applied in polymers has been reported for several decades, which is considered to be a kind of novel halogen-free flame retardants with high efficiency, low smoke release and nontoxic gases production. In general, IFR mainly consisting of three basic components, namely, an acid source, a char-forming agent, and a blowing agent.
Chapter I (Introduction): Introduction explains the polymers and their application in our life and the limitation of their using, and the fundamentals of polymer combustion. The introduction shows the meaning of polymer flame retardant materials and explaining in details the effect of the flame retardant on polymers. Moreover, the intumescent flame retardant was defined in details and the basics of intumescence and its formulations used in thermoplastic and thermoset materials were explained. The fire toxicity and the analysis of main toxic gases
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concentration in fire by cone calorimeter coupled with online FTIR was covered in the introduction. Also the calculation of FED and LC50 for testing toxicity of materials in bench-scale tests with a cone calorimeter. Finally, the Motivation in the present work.
Chapter II (Experimental): Three flame retardant compounds have been prepared and their structures supported by IR and H1NMR techniques. 1. Melamine salt of montmorillonite phosphate (MMP)
2. Melamine salt of pentaerythritol phosphate montmorillonite (MPPM)
3. Melamine salt of chitosan phosphate (MCHP)
The prepared compounds were incorporated into linear low density polyethylene (LLDPE) in different ratios. Different characterizing instruments were used in our measurements such as Thermogravimeteric analysis (TGA), Flame spread apparatus, a cone calorimeter coupled with online FTIR (CC−FTIR).
Chapter III (Results and discussion): The results of Thermogravimetric analysis (TGA) showed that the thermal degradation of LLDPE and its composites with all new intumescent flame retardant has been improved the thermal stability of all polymer composites at high temperatures with high values of char residue due to the formation of thermally stable char .
- The vertical burning rating test (UL-94V) for LLDPE give no rating, while for MMP, MPPM, and MCHP with LLDPE give V-0 for PE/7, PE/35, and PE-4 respectively, and V-2 for all other composites.
- The data from cone calorimeter of all polymer composites indicate improvement of flammability properties of polymer composites. The addition of MMP and MMP/ZB into LLDPE reduced the value of pHRR, THR, mHRR, mMLR, and improved the fire safety parameters of LLDPE. where PE/4 give the best reduction of pHHR, mHRR, mMLR, (and fire safety parameters, which make improvement in FPI, FGI, and MARHE. PE/6 gives the best reduction of THR.
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The addition of MPPM into LLDPE reduced the value of pHRR , THR, mHRR, mMLR, and improved the fire safety parameters of LLDPE. PE/35 give the