بررسي مقاومت در برابر اشتغال كامپوزيت هاي رزين اپوكسي /الياف شيشه/نانو لوله كربن

چكيده انگليسي :

Study on Flame Retardancy of Epoxy Glass Multi Walled Carbon Nanotube Composites Mahdis Hesami m hesami@ce iut ac ir 2011 3 13 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Roohollah Bagheri bagheri@cc iut ac ir Mahmood Masoomi mmasoomi@cc iut ac irAbstractFiber reinforced polymer composites have been widely used in many applications due to their light weight high specific stiffness and high specific strength Among various polymer matrices epoxy resins haveattracted interests because of their excellent mechanical performance low shrinkage high dimensionalstability and good impregnation and adhesion to fiber reinforcement One of the disadvantages of epoxyresins is their flammability which reduces their applications So it is necessary to use flame retardants inepoxy resin matrice Environmental standards have restricted the use of halogenated flame retardants becauseof their toxicity The aim of this investigation is to study the effect of carbon nanotubes on thermal resistanceand flame retardancy of epoxy glass fiber composites Dispersion of nanotubes in the polymeric matrix is animportant factor which influences thermal and flame retardant behavior of the final sample In order todisperse multi walled carbon nanotubes MWCNT in the epoxy resin four methods were employed Microscopic observations SEM showed that the best dispersion state was gained by using ultrasonicationmethod and high shear flow simultaneously Surface functionalization of carbon nanotubes was another wayto improve the dispersion state According to microscopic observations amino functionalized carbonnanotubes had better dispersion compared to unfunctionalized nanotubes and carboxylated MWNTs Thermalproperties of epoxy nanotube samples were investigated by thermo gravimetric analysis TGA Introducing0 25 0 5 MWNTs and 0 25 amino MWNTs to epoxy resin increased the initial thermal decompositiontemperature IDT up to 32 C 42 C and 37 C respectively To study flammability properties of fiberreinforced composites Limiting Oxygen Index LOI was employed The results showed that as thenanotube loading increases LOI reaches to a maximum value and then decreases The maximum value wasobtained at 0 7 These results also have showed that introducing 0 7 MWNTs increases LOI from 26 6 to32 Inorder to achieve better flame retardancy properties nanotubes were combined with a nano clay MMT and also a combination of nanotubes and ammonium polyphosphate APP was employed LOI resultsconfirmed the synergistic effect between nanotube and nano clay and also nanotube and APP Introducing0 7 nanotube and 5 nano clay to epoxy glass composites increased LOI from 26 6 to 34 Also thecombination of 0 7 nanotube and 15 APP improved this value to 37 Former researches showed thatintroducing 15 APP to epoxy glass composites increases LOI from 26 6 to 32 Although the samplescontaining 0 7 nanotube had maximum LOI but they didn t show improvement in thermal resistance Onthe other hand 0 5 nanotubes improved thermal resistance and also increased LOI from 26 6 to 32 So thesamples contained 0 5 MWNTs were selected to evaluate by cone calorimeter The cone calorimetry resultsshowed that introducing 0 5 MWNTs decreases peak of heat realese rate and total heat released to 10 and 12 respectively The reduction of these two parameters means that epoxy glass composites have beenflame retarded this test also showed that introducing 0 5 MWNT decreased the amount of carbon monoxideand carbon dioxide which were released during combustion Keywords epoxy resin fiber reinforced composite glass fibers carbon nanotube flameretardancy thermal resistance

حسامي، محديث

بررسي مقاومت در برابر اشتغال كامپوزيت هاي رزين اپوكسي /الياف شيشه/نانو لوله كربن

مقاومت گرمايي , كامپوزيت ليفي