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Interaction between poly(m-phenylene isophtalamide) (PMIA) electrospun nanofibers and commercial epoxy resin precursor during the cross-linking process was investigated, in order to use such polyaramidic nanofibers for composite materials reinforcement. Hence nanofibrous PMIA mats were produced via electrospinning technique to be used for the functional modification of the epoxy matrix composite properties. When adding such fibers to an epoxy resin precursor, it was observed a strong influence on the kinetics of its curing process. The final results, however, demonstrates that boosting the reaction condition (raising the temperature and the reaction time) the curing is pushed to completion, indicating that the cross-linking process of the resin is just delayed and not completely hampered. It will be therefore necessary to rethink the composite cure cycle when PMIA nanofibers are added to the composite material, in order to attain significant improvement of the final composite performance.

This paper investigates the effect of a prolonged acid attack on the surface of PTFE by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). PTFE is a very non-reactive polymer, partly due to the strength of carbon–fluorine bonds, and for this reason it is often used in containers and pipework parts in contact with reactive and corrosive chemicals. The PTFE under analysis is commercialized by two manufacturers in form of Teflon adhesive tapes. These tapes are used as gaskets in a tyre moulds cleaning plant, based on different acid baths and ultrasonic waves. In particular, PTFE gaskets show anomalous phenomena of surface degradation in a relatively short operation time. Nevertheless, even considering the combined effect of ultrasonic waves, temperature, humidity and acid attack, PTFE properties nominally exclude the risk of the extreme erosion phenomena as observed. The present experimental research aim at investigating this contradiction. In this study PTFE samples have been treated with different mixes of acids, in order to investigate the different aging effects. The infrared and thermal analysis has permitted the characterization of PTFE surface and core properties after acid attack, providing evidence of the degradation phenomena. In particular, the different acid treatments adopted for the aging of gaskets have highlighted not only the different response of the PTFE matrix, but also differences between manufacturers.

Osservazioni condotte su impianti innovativi per la pulizia degli stampi utilizzati nella formatura dei pneumatici hanno messo in evidenza come le guarnizioni commerciali in teflon (PTFE) presentano un fenomeno di degrado imprevisto, non compatibile con le condizioni nominali di impiego e che lasciano intuire la presenza di fenomeni complessi. Si tratta di impianti che consentono la pulizia di stampi, quantunque complessi, attraverso la loro immersione in vasche di lavaggio e l’azione combinata di ultrasuoni, prodotti chimici, temperatura ed agitazione del liquido. La sovrapposizione dei diversi effetti fisici e chimici crea una situazione di forte stress chimico-meccanico su tutta la struttura di impianto, compresi gli elementi di connessione e contenimento. Alcune fuoriuscite di liquido, osservate durante il funzionamento degli impianti anche dopo un periodo di funzionamento relativamente breve, hanno concentrato l’attenzione sulle guarnizioni. Queste sono state appositamente sottoposte a degradazione controllata e successiva caratterizzazione sperimentale per investigare meglio la situazione. In particolare, questo studio descrive le condizioni di degradazione del teflon e riporta i risultati ottenuti mediante analisi spettroscopia infrarossa (FT-IR), calorimetria differenziale a scansione (DSC) e analisi termogravimetrica (TGA) in funzione del processo di degradazione Abstract This paper describes the accelerate aging tests used for investigating the surface alteration of PTFE gaskets commercialized by two alternative producers. These gaskets are installed in modern process plants where tires moulds are cleaned by a multistage ultrasonic process. Their surface degrades inexplicably under ordinary operative conditions after a relatively short period. Even if these gaskets are exposed to a combination of ultrasonic waves, temperature, humidity and acid attack, the PTFE properties of resistance nominally exclude the possibility of severe erosion phenomena as highlighted during the real utilization. A possible explanation could be represented by the presence of unexpected chemical compounds emerging from the disaggregation of highly reacting elements from the tire composition.. Thus, the experimental characterization of PTFE properties has to follow an appropriate accelerated aging, aiming at actuating the specific mechanics of wearing as in industrial use.

Novel optically active methacrylic homopolymers bearing in the side-chain both one or more chiral groups of one single configuration (L-lactic acid residue) and tetraphenylporphyrin moieties have been successfully synthesized and fully characterized. These intrinsically chiral polymers exhibit remarkable thermal stability, with glass transition temperature in the range 250-315°C and decomposition temperatures in the range 360–390°C. Spectroscopic, thermal and chiroptical characterizations indicate the occurrence of dipolar interactions among the side chain moieties and the presence of chiral helix conformation at least for chain segments of the macromolecules. The macromolecular chromophoric materials resulted able to bind chiral guests through nitrogen/zinc coordination to form complexes which exhibit exciton-coupled bisignate Circular Dichroism (CD) spectra with the signs reflecting the absolute configurations of the optically active compound (to determine the absolute configuration of ,-diamines). This behavior is due to the formation of diastereomeric complexes which lead to a preferred porphyrin helicity, at least for chain segments. The method turns out very sensitive, requiring only few microgram quantities of guest compound.

La presente invenzione si riferisce ad un metodo per la produzione di poliuretano espanso. La presente invenzione si riferisce anche a poliuretano espanso comprendente ossido di grafene.

Plant (1) for transforming into raw and secondary material, or disposing of, used tyres (P), made of rubber or other carbon matrices, comprising at least one pyrolysis chamber (6), wherein said used tyres (P) are subjected to pyrolysis 5 treatment, said tyres (P) being conveyed to said at least one pyrolysis chamber (6) by means of at least one supplying device (5) that receives the tyres (P) from a first conveying device (3) and conveys the tyres (P) to said at least one pyrolysis chamber, said plant (1) comprising at least one hydraulic seal element (9) associated with said at 10 least one supplying device (5) and heating means (16) for heating said at least one pyrolysis chamber (6), characterised in that it comprises at least one supplying conduit (11) through which said tyres (P) are conveyed, said at least one supplying conduit mainly extending vertically and being interposed between said at least one hydraulic seal element (9) and said at least one pyrolysis chamber (6), an end 15 portion (15) of said at least one supplying conduit (11), in contact with said at least one pyrolysis chamber (6), being made of a thermally insulating material. 2. Plant (1) according to claim 1, wherein said at least one supplying conduit (11) communicates with an inlet opening (13) of said at least one pyrolysis chamber, said inlet opening (13) being provided with a movable closing element (14) coated 20 with thermally insulating material. 3. Plant (1) according to claim 2, wherein said movable closing element (14) can rotate around a hinge element (16) between a closed position and an open position. 4. Plant (1) according to claim 3, further comprising an actuator (36) suitable for driving said movable closing element (14) so that it rotates around said hinge 25 element (16). 5. Plant according to any one of claims 2 to 4, wherein said at least one supplying device (5) comprises a second conveying device (7) that receives the tyres (P) from the first conveying device (3) and conveys the tyres (P) through said at least one hydraulic seal element (9) and along said at least one supplying conduit (11) until 30 reaching an inlet zone (12) of the at least one pyrolysis chamber (6), where said tyres (P) are released by said second conveying device (7) and drop by gravity into said pyrolysis chamber (6) through said inlet opening (13). Plant (1) according to claim 1, or 2, characterised in that it comprises a plurality of pyrolysis chambers (6) each of which is supplied with said tyres (P) by means of a respective supplying device (5), that receives the tyres (P) from the first conveying device (3) and conveys the tyres (P) to a respective pyrolysis chamber (6) through a respective supplying 5 conduit (11). 7. Plant (1) according to any preceding claim, wherein said at least one supplying conduit (11) extends vertically over a length of at least 4 metres, in particular over a length comprised between 4 and 20 metres. 8. Plant (1) according to any preceding claim, wherein said second conveying device 10 comprises a rung conveyor (7). 9. Plant (1) according to any preceding claim, wherein said at least one hydraulic seal element (9) comprises a tank (10) containing a liquid (L), in particular water or oil.

Un metodo di produzione di un componente in materiale composito per applicazioni in ambito automotive; in cui il metodo prevede di ottenere il componente in materiale composito a partire da fibre di carbonio e da una matrice polimerica; ed in cui il metodo prevede inoltre di aggiungere un derivato grafenico alla matrice polimerica in modo tale che la matrice polimerica presenti una concentrazione di derivati grafenici inferiore o uguale a 1,5 %.

Since first successfully separated from graphite by micromechanical cleavage, graphene has emerged profuse interests of researchers all over the world, owing to its exceptional properties, such as high electrical conductivity, thermal conductivity, surface area and tensile strength. These remarkable properties make this two-dimensional carbon material a promising substitute for other carbon-based materials, such as carbon black, expanded graphite and carbon nanotube, as fillers for polymer carbon nanocomposites. As intensive studies have demonstrated, graphene can enhance tensile modulus and strength of most polymer nanocomposites more effectively than other carbon fillers. In this context, a commercial two-components formulation to produce epoxy resins was modified by adding graphene derivatives. Upon curing, mechanical properties at break for the nanocomposites is increased to respect the original plain resin values. Furthermore, the behavior of the modified resins was simulated when used for thick composite production where the reinforcement is made of long carbon fibers.

NOVELTY - Plant for transforming into secondary raw material, or disposing of used tires, made of rubber or other carbon matrices comprising a pyrolysis chamber, comprises first hydraulic sealing means placed at the entrance to the pyrolysis chamber, heating means for heating the pyrolysis chamber, first evacuating means for evacuating from the pyrolysis chamber gaseous substances produced during the pyrolysis treatment and second evacuating means for evacuating from the pyrolysis chamber solid residues of the pyrolysis treatment. USE - The plant is useful for transforming into secondary raw material, or disposing of used tires, made of rubber or other carbon matrices (claimed). ADVANTAGE - The plant for continuous-cycle treatment of used tires by pyrolysis does not require costly tire-shredding operations or require the use of suitable containers for conveying the tires to the kiln in which treatment by pyrolysis occurs. DETAILED DESCRIPTION - Plant for transforming into secondary raw material, or disposing of used tires, made of rubber or other carbon matrices comprising a pyrolysis chamber, in which the used tires are subjected to pyrolysis treatment, the tires being conveyed to the pyrolysis chamber by conveying means, comprises first hydraulic sealing means placed at the entrance to the pyrolysis chamber, heating means for heating the pyrolysis chamber, first evacuating means for evacuating from the pyrolysis chamber gaseous substances produced during the pyrolysis treatment and second evacuating means for evacuating from the pyrolysis chamber solid residues of the pyrolysis treatment, where it comprises cutting or punching means that is suitable for making a hole in each of the tires, or for subjecting the tires to a cutting operation along one or more diametral planes, or along a plane that is perpendicular to an axis of the tire.