Thermal and structural response of in situ prepared biobased poly(ethylene 2,5-furan dicarboxylate) nanocomposites

Poly(ethylene 2,5-furan dicarboxylate) (PEF) is considered the biobased counterpart of the fossil based poly(ethylene terephthalate) for food packaging. In this research, PEF nanocomposites containing 2.5 wt% neat multi walled carbon nanotubes (MWCNTs), or functionalized MWCNTs or graphene oxide (GO), were in situ prepared by applying the melt polycondensation method. The nanocomposites showed faster crystallization rates compared to the pristine material as proved by both differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The latter evidenced an increased nucleation density in nanocomposites, due to the nucleating efficiency of the fillers, resulting in smaller spherulite size. However, a slightly reduced thermal stability was revealed for the nanocomposites by thermog-ravimetric analysis (TGA), especially in the case of GO-containing samples. The solid structure of the materials was studied by performing real time X-ray diffraction (XRD) measurements. In neat PEF, beta-crystals were observed in the solvent treated sample, while alpha-crystals were formed on cooling from the melt or cold-crystallization. On the contrary, in the XRD patterns of the nanocomposites only peaks associated with the alpha-crystal phase were found. Last, but not least, the effect of recrystallization on the thermal behavior was evaluated by means of modulated temperature DSC (MDSC). (C) 2016 Elsevier Ltd. All rights reserved

Biobased poly(ethylene furanoate-:Co -ethylene succinate) copolyesters: Solid state structure, melting point depression and biodegradability

Novel, biobased poly(ethylene furanoate-co-ethylene succinate) copolyesters were successfully prepared by melt polycondensation and their solid state structure, melting point depression and biodegradability were evaluated in detail.</p

AEROBIC DEGRADATION OF MEDIUM DENSITY FIBERBOARD (MDF) AS A WOODMANUFACTURING INDUSTRY WASTE WITH COMPOST ADDITION

The fiberboard waste constitutes in our days an important part of urban waste stream, because they are used in increasing amounts, for the production of interior wood constructions. The management of such waste already troubles the modern societies. However, via biodegradation it is possible this waste material to constitute a valuable resource for the production of new wood based panels, thus helping on one part in the partial satisfaction of increased needs for wood and on the other part in the restriction of problems caused by these materials when they are disposed. The aim of this researchwas to study the influence of compost in degrading formaldehyde adhesives so that a large percentage could be reused as wood waste panels or further environmental disposal. Particularly we managed to determine whether the contact of these two materials favors the degradation of formaldehyde adhesives. It was used small chamber test in stable conditions (temperature, moisture, weight) for 21 days period, using wood waste from the same fiberboard in order to reduce heterogeneity problems. Further removal of formaldehyde, confirms that compost could be a favorable factor in wood waste degradation. Nevertheless, it is particularly important the way that compost participates in process

Synthesis and study of novel furanoate polyesters

The basis of the present dissertation was the imperative need for development of new biobased materials, capable of replacing or even exceeding their homologues that are oil derivatives. In the present study, the synthesis of furanoate polyesters was carried out by using the dimethylester of FDCA (DMFD) and diols with 2-6 carbon atoms via the basic polymerization technique (PEF, PPF, PBF, PPeF and PHF), while for the diols with 7-12 carbon atoms (with an exception of 11 carbon atoms) a variation of the basic technique was applied (PHepF, POF, PNF, PDeF and PDoF).The study of the polyesters included viscosity measurements, 1Η-NMR, XRD, PLM, DSC, TGA and Py-GC/MS, while for POF, PNF, PDeF and PDoF tensile test was applied. In conclusion, the synthesized polyesters are semicrystalline materials with high nucleation density, they are thermal stable and they produce a plenty of compounds by degradation. Increasing the number of carbon atoms, Tg decreases, while Tm follows the “even-odd number” effect. Finally, the tensile strength of POF, PNF, PDeF and PDoF is higher when the number of methylene groups in the repeat unit is lower.Βάση της συγκεκριμένης διδακτορικής διατριβής αποτέλεσε η επιτακτική ανάγκη για την ανάπτυξη νέων υλικών από πρώτες ύλες που προέρχονται από ανανεώσιμες πηγές, ικανά να αντικαταστήσουν ή ακόμη και να υπερβούν, τα ομόλογά τους που είναι παράγωγα πετρελαίου. Πραγματοποιήθηκε η σύνθεση και η μελέτη των φουρανοϊκών πολυεστέρων (PEF, PPF, PBF, PPeF, PHF, PHepF, POF, PNF, PDeF, PDoF) με αντιδρώντα το διμεθυλεστέρα του FDCA (DMFD) και τις γραμμικές διόλες από 2 μέχρι 12 άτομα άνθρακα, εκτός της 1,11-εντεκανοδιόλης.. Η σύνθεση των πολυμερών έγινε με τη βασική τεχνική πολυσυμπύκνωσης τήγματος δύο σταδίων. Για τις διόλες με υψηλό μοριακό βάρος (με 7, 8, 9, 10 και 12 C) εφαρμόστηκε μια παραλλαγή της βασικής τεχνικής. Η μελέτη των ιδιοτήτων των πολυεστέρων περιλάμβανε ιξωδομετρία, 1Η-NMR, XRD, PLM, DSC, TGA, Py-GC/MS, ενώ στους πολυεστέρες POF, PNF, PDeF, PDoF εφαρμόστηκε και δοκιμή αντοχής στον εφελκυσμό. Συμπερασματικά προέκυψε ότι οι πολυεστέρες είναι ημικρυσταλλικά πολυμερή με υψηλή πυκνότητα πυρήνωσης, είναι θερμικώς σταθερά και όταν διασπώνται δίνουν πλήθος ενώσεων. Με αύξηση του αριθμού των ατόμων άνθρακα της ΕΔΜ το Tg μειώνεται, ενώ το Tm ακολουθεί το φαινόμενο του άρτιου-περιττού αριθμού μεθυλενομάδων. Τέλος, η αντοχή στον εφελκυσμό των POF, PNF, PDeF και PDoF βελτιώνεται με μείωση του αριθμού μεθυλενομάδων στην ΕΔΜ των πολυεστέρων