An Integrated Approach to Design Fluoro Substituted “Smart” Polymers for Protection of Monumental Buildings

Introduction of fluorinated groups in the structure of either fully acrylic or acrylic - vinyl ether copolymers, is achieved through the use of commercially available or specifically synthesized fluorinated acrylic comonomers. If suitably selected, these fluoroacrylates can allow both control on the macromolecular structure and tailoring of material properties that are relevant for coating applications, such as film-forming behavior, adhesion, water repellency and intrinsic photostability. Several copolymers of fluorinated acrylates and methacrylates with not-fluorinated methacrylates and vinyl ethers have been evaluated in terms of chemical stability under accelerated photoaging conditions, and their behavior as protective coating materials has been studied after application to various stone substrates that are commonly found in ancient buildings and objects of cultural significance

riutilizzo dei materiali polimerici

Il presente volume vuole sottolineare come le materie plastiche possono essere sempre recuperate e rivalutate sotto forma di recupero di materia e, quando non più possibile, di energia grazie al loro elevato potere calorifico. La crescita delle materie plastiche negli ultimi anni si è aggirata intorno al 6%, superiore a quella della carta e dell’acciaio, ne consegue la grande importanza del suo recupero a fine vita, dai cosiddetti “giacimenti metropolitani”. Il testo è dedicato al recupero dei materiali plastici; vengono esaminate nei dettagli le operazioni di raccolta, di separazione e purificazione di tutti i rifiuti provenienti dalla raccolta differenziata, valutando gli aspetti normativi, gestionali e tecnologici di questi processi. Viene trattato il riciclo partendo da una classificazione dei metodi che permettono di arrivare a potenziali materie prime e seconde e viene esaminato il processing di materiali polimerici post-consumo che, opportunamente miscelati, possono portare alla preparazione di nuovi materiali polimerici. Si è dedicato spazio alle plastiche da imballaggio e al potenziale recupero delle plastiche dai veicoli a fine vita e dalle apparecchiature elettriche ed elettroniche e infine alle prospettive del riciclo considerando l’avvento delle nuove bioplastiche

Influence of the transesterification catalyst structure on the reactive compatibilization and properties of poly(ethylene terephthalate) (PET)/dibutyl succinate functionalized poly(ethylene) blends

The transesterification between poly(ethylene terephthalate) (PET) and dibutyl succinate functionalized polyethylene (POF) was studied by preparing blends in a discontinuous mixer in the presence of different Zn and Ti catalysts. In particular the catalytic activities of Zn(OOCCH3)2, Ti(OBu)4, ZnO and TiO(OCCH3)2 were compared. The mechanism of reactions occurring in the melt was studied both by a model compounds approach and by characterizing the macromolecular products of the melt processing by means of selective extractions, infrared analysis and the determinations of the molecular weight of PET. The results are discussed in terms of electrophilicity and nucleophilicity of the different catalysts. The catalysts structure also affected the phase distribution. In fact from a morphologic point of view in PET matrix blends the use of zinc derivatives yielded preferentially dispersed-like phase distribution, while the use of titanium derivatives resulted in partially co-continuous phase morphology. The stability of the attained phase distribution was also monitored during compression moulding and it evolved rapidly in fully dispersed phase morphology. The tensile properties of compression moulded films revealed that the occurred reactions and morphological assessment induced a general decrease of tensile modulus and an increase of elongation at break

Poly(ethyleneterephthalate) (PET) degradation during the Zn catalysed transesterification with dibutyl maleate functionalized polyolefins

The chemical reactions occurring during the melt blending between a dibutyl maleate functionalized polyolefin (POF) and poly(ethylene terephthalate) (PET) in the presence of Zn(OOCCH3)2$2H2O were studied as a function of blending conditions, such as the preliminary drying of PET, the presence of a nitrogen flow during blending and the time of blending. The selective extraction of POF/PET 30/70 by weight blends to remove unreacted PET and the determination of its molecular weight by viscosimetric measurements allowed to evaluate both the grafting points’ number and the molecular weight of PET. In this way the impact of degradation of PET onto its grafting by transesterification onto POF was investigated. The examined blending conditions were shown to affect both PET degradation and POFePET copolymer formation. In order to correlate data about macromolecular and morphological structure with the final properties of the blends, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and tensile tests were also carried out