Επικάλυψη κόκκων πολυπροπυλενίου με γραφένιο για την παραγωγή σύνθετων υλικών με τεχνολογίες τήγματος

Παπαδημητρίου, Γεώργιος; Papadimitriou, Georgios

dc.contributor.author	Παπαδημητρίου, Γεώργιος	el
dc.contributor.author	Papadimitriou, Georgios	en
dc.date.accessioned	2016-03-29T12:52:33Z
dc.date.available	2016-03-29T12:52:33Z
dc.date.issued	2016-03-29
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/42273
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.10594
dc.rights	Default License
dc.subject	Γραφένιο	el
dc.subject	Οξείδιο του γραφίτη	el
dc.subject	Τεχνολογίες τήγματος	el
dc.subject	Πολυπροπυλενίο	en
dc.subject	Παραγωγή συνθέτων	el
dc.title	Επικάλυψη κόκκων πολυπροπυλενίου με γραφένιο για την παραγωγή σύνθετων υλικών με τεχνολογίες τήγματος	el
heal.type	bachelorThesis
heal.classification	Χημική μηχανική	el
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2015-10-08
heal.abstract	Ο σκοπός αυτής της διπλωματικής εργασίας είναι η εξέταση μεθόδων παρασκευής και η μελέτη θερμικών και μηχανικών ιδιοτήτων συνθέτων πολυπροπυλενίου (PP) με γραφένιο.Για το πειραματικό κομμάτι της εργασίας, παρασκευάστηκε σύνθετο PP με γραφένιο με τρεις διαφορετικές τεχνικές και τα δοκίμια που παρασκευάστηκαν συγκρίθηκαν μεταξύ τους κυρίως ως προς τις θερμομηχανικές ιδιότητες.	el
heal.abstract	The purpose of this diploma thesis is to examine the methods of preparation and study of thermal and mechanical properties of polypropylene composites (PP) with graphene. Graphene is an allotropic form of carbon which was discovered in 2004 and is an interesting subject of research due to its exceptional electrical, mechanical and optical properties. Graphene is prepared by exfoliation of graphite having a laminate structure. Various methods have been developed for the exfoliation of laminate materials (mechanical, chemical peeling). Graphene rivals traditional aid instruments, as well as presents less manufacturing cost compared with carbon nanotubes and is more environmentally friendly than the organically modified montmorillonite. Furthermore, it's characterized by a combination of high thermal, mechanical, electrical and optical properties, as well as a high ratio of diameter / thickness. For those exact reasons it's selected as an aid instrument in this thesis for the preparation of compound PP with graphene. For the experimental part, composite PP was prepared with graphene in three different ways and prepared composites were compared to their mechanical properties. First, there was coated granules (PP) with expanded graphite (EG) at concentrations of 0.1, 0.25 and 0.5 wt%, followed by the preparation of the composite by mixing the coated granules in twin screw extruder. Then, composites were prepared by coating granules (PP) with expanded graphite in the same proportions and direct molding in a heated plates press (without using the extruder). Finally, composite was prepared, in the same concentrations of expanded graphite, by direct mixing in twin screw extruder of expanded graphite and PP and later of the graphite oxide and PP. The composites obtained were characterized for the thermal transitions and crystallinity by differential scanning calorimetry (DSC), while their thermal stability was evaluated in an inert nitrogen environment by thermogravimetric analysis (TGA). Even more, with the use of the RAMAN instrument measurements were made to estimate the number of graphene layers located within the composite s. Also, tensile samples and films were created with the heated plates press and were estimated for the ir mechanical properties with tensile tests and their permeability of oxygen. More specifically DSC showed that the expanded graphite affects the crystallization temperature by increasing its value by 4-6 ° C, the enthalpy of crystallization was 3-6 mW lower than the neat polypropylene and the melting enthalpy was also 2-3 mW lower than the neat polypropylene, although the melting temperature appears to not be influenced by the expanded graphite. Also, TGA showed that the expanded graphite decelerates 9 the thermal degradation of the composites since the degradation onset temperature was increased by about 20 ° C. It’s also observed that depending on the manner of incorporation of expanded graphite in the polymer matrix we sometimes improve their mechanical properties and other times reduce their values. Remarkable was the increase of young modules (20-30%) from the technique of directly mixing polypropylene granules with expanded twin screw extruder system and the decrease of 50-60% of the value to the elongation at fracture for all composites which leads to the conclusion that composite materials is more brittle than the neat polypropylene. Finally, measurements that were made regarding the oxygen permeability showed an increase in the concentration of oxygen that permeates the film of composite.	en
heal.advisorName	Ταραντίλη, Πετρούλα	el
heal.committeeMemberName	Ανδρέοπουλος, Ανδρέας	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Χημικών Μηχανικών. Τομέας Σύνθεσης και Ανάπτυξης Βιομηχανικών Διαδικασιών (IV). Εργαστήριο Τεχνολογίας Πολυμερών	el
heal.academicPublisherID	ntua
heal.numberOfPages	138 σ.
heal.fullTextAvailability	true