A. Pollicino

Natural Ageing of Automotive Polymer Components: Characterisation of New and Used Poly(propylene) based Car Bumpers

The chemical and morphological structure of new and post-consumer ten years old poly(propylene) based car bumpers has been investigated and their mechanical properties have been correlated to the chemical and physical degradation of the material. Poly(propylene) matrix and a rubbery ethylene-propylene phase were the constituents of the bumpers. A strong impairment of the mechanical properties has been found in old samples which showed also a distinctive phase separation. The modification of the chemical structure was much less evident: oxidation on the exposed surface involving the poly(propylene) phase has been highlighted in old bumpers, and possible crosslinking. These relatively small changes, however, are responsible for the pronounced physical ageing. A tentative explanation is a poor interfacial adhesion of rubber particles from which the crazes can propagate further to form cracks.

An investigation of the structure?property relationships in ionic polymer polymer composites (IP2Cs) manufactured by polymerization in situ of PEDOT/PSS on Nafion?117

Ionic polymer polymer composites (IP2Cs) are all-organic electroactive polymers (EAPs) that show sensing and actuation capabilities when a deformation or a voltage is applied, respectively. They are fabricated starting from an ionic polymer coated on both sides with a conducting polymer as electrode element. In this work, poly(3,4-ethylendioxytiophene)–poly-(styrenesulfonate) (PEDOT/PSS) has been polymerized directly on Nafion®117 membrane and devices have been manufactured varying the polymerization time. Water and ethylene glycol (EG) have been used as solvents. The obtained IP2Cs have been characterized using thermal and mechanical analyses and electromechanically tested. The results have shown that in IP2Cs manufactured by polymerization in situ the PEDOT/PSS layer adheres very strongly on the Nafion®117 film, improving the possibility of rehydrating the devices after use. Moreover, taking into account that the different polymerization times influence the uniformity of the surface of the organic electrode and, consequently, both device stiffness and electrode conductivity, the structure–property relationships of the obtained devices have been investigated. The influence of the different solvents inside the devices has also been studied when IP2Cs have been used as actuators or sensors. Reported results show that it is possible to modulate the performances of IP2Cs by varying some manufacture parameters and the solvent.

Synthesis and characterization of new polyamides containing 6,6′-methylenediquinoline units

Abstract Aromatic polyamides have been synthesised from a new monomer containing a 6,6′-methylenediquinoline unit by reaction with various diamines by the phosphorylation route. The polymers have been characterised by elemental analysis, infrared, thermogravimetric analysis and differential scanning calorimetry. The polyamides, obtained in quantitative yield, possessed inherent viscosities in the range 0.20–0.85 dl g −1 , 10% weight loss in nitrogen and air above 420°C and glass transition temperatures in the range 184–294°C. The polyamides obtained by reaction of this new monomer with 4,4′-oxydianiline and 4,4′-methylenedianiline were soluble on heating in N -methyl-2-pyrrolidone and partially soluble in dimethylacetamide. The properties of these polymers are compared with those of corresponding polyamides having only one quinoline ring per repeat unit.

Realization and characterization of carbon black based fractional order element

Abstract In this papers the possibility of realizing fractional capacitors by using carbon black nanostructured dielectrics is investigated. Capacitors have been realized by varying the percentage of distributed carbon black. The frequency analysis of the capacitors has been, therefore, performed. The Bode diagrams outline that this class of devices shows a non integer order behavior. Moreover, a dependance between the curing temperature and the fractional order has been shown.

Study of an ionic polymer-metal composite based flowmeter

The investigation of a vortex shedding flowmeter is described. The flowmeter has been realized by using a polymeric mechanoelectrical transducer. The system has been investigated by using an ad-hoc realized setup. Data have been elaborated to determine the performance of the flowmeter in several working conditions.