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العنوان
Synthesis of Nano-sized Ammonium Polyphosphate Modified with Clays as Flame Retardant for Some Polymeric Materials /
المؤلف
Abdelmoaty, Alaa Salah Ahmed.
هيئة الاعداد
باحث / Alaa Salah Ahmed Abdelmoaty
مشرف / AdliAbdalla Hanna
مشرف / Mohamed Ali Nour
مناقش / Marwa Adel El-Sherief
تاريخ النشر
2018.
عدد الصفحات
136p. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
الكيمياء
تاريخ الإجازة
1/1/2018
مكان الإجازة
جامعة عين شمس - كلية العلوم - الكمياء
الفهرس
Only 14 pages are availabe for public view

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Abstract

Flame retardants are compounds added to the manufactured materials such as polymers, textile, cellulosic materials and surface finishes as coating that inhibits, suppress, or delay the production of flames to prevent the spread of fire. It includes two main categories:-
1-Additives flame retardants.
2-Reactive flame retardants.
The flame retardants materials may be natural ores such as clays or diatomite and zeolite or chemical compounds such as hydroxide of metals, halogen compounds and phosphorus compounds.
The main target of this thesis is to increase the efficiency of ammonium polyphosphate (APP) when used as flame retardant for PP. This improvement goes in two directions: the first one is modifying the morphology and the particle size of the prepared ammonium polyphosphate and the second direction is additives of raw materials such as kaolin and montmorillonite. Also, the aim of this thesis extends to modify the kaolin and montmorillonite before adding to the polymer.
Polypropylene (PP) is a good material for different industrial applications such as thermoplastic owing to its easy processing and good mechanical strength, a major advantage of PP is its ability to be used in a wide range of fibrous and non woven, because it is easy processing and have a good mechanical properties. The main drawback of PP is its flammability, so that different improvements were due to delay the flammability of it.
The thesis consists of three main chapters; the first chapter contains the scientific introduction and the local and global statement of the burns and the flame retardants materials. Literatures review about
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the types of the flame retardant materials and the improvement of the property of these materials. The flame retardant materials are classified into: organic flame retardants andinorganic flame retardants materials.Intumescent flame retardants and the encapsulation flame retardants materials. The foregoing of the literature review show that the most successful materials for polymers is the APP because it isrich with nitrogen and phosphorus metals. APP degraded thermally to give nitrogen which inhibits spread the fire and polyphosphoric acid which isolate the flame and the surface of polymer.
The second chapter contains the materials and the methods of preparation and the modification of either APP or clays before adding, to increase the surface area and decrease the particle size of APP. It is prepared from available precursors materials under specific conditions to give a nano-sized particles ranging from 5nm to 85nm. The prepared APP particles were characterized by using the spectroscopic techniques. Also, the modification of clays was carried out by acid treatment by H2SO4, to study the change in the composition and the structure. The method of incorporation of the APP/clays into the PP particles was carried out according to the recommended method.
Chapter three contains the results and discussion. The analysis of the obtained results shows that:-
1. The results of analysis by x-ray fluorescence (XRF) showed that the modification of clays increases the percentage of SiO2 and decrease the percentage of Al2O3 with minor changes in the other contents such as MgO and Fe2O3.
2. To evaluate the flame retardant action of APP, APP/ untreated kaolin, APP/ treated kaolin, APP/ untreated montmorillonite and APP/ treated montmorillonite. Two techniques were used, the
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first one is the thermogravimetric analysis (differential thermal analysis and thermal gravimetric analysis (TGA) and the second is the Cone calorimeter test (CCT). Following the TGA and DTA profiles indicates that the adding of a certain amount of kaolin and montmorillonite improve the flammability and the thermal stability of the polymer.
3. The CCT of the PP samples with APP and with APP+ clays show that the values of heat release rate (HRR) and Peak of heat release rate (pHRR) reduced by adding clays to APP which means that the flammability of PP improved by adding the flame retardant materials.
4. The action of APP/clays explained in the light of the literature review according to the mechanism which include the decomposition of APP and the coating of APP particles by clays.
5. The improvement action of APP when used as flame retardant for PP following sequence PP< PP/APP< PP/APP+ untreated kaolin< PP/APP treated kaolin< PP/untreated montmorillonite, treated montmorillonite.