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Imidazole (IMI) (from 18.7 to 300 mg/Kg) i.p. injected in adult rats induced shaking, which was antagonized by both morphine (MOR) and ha loperidol (HALO) but not by methysergide (MET). I.p. IMI pretreatment inhibited the penile erections (PE) and stretching and yawning (SY) typically elicited by N-n-propylnorapomorphine (NPA), a well-known CNS dopamine (DA) receptor stimulant, injected either i.p. or i.c.v., whereas it enhanced stereotyped behavior (SB). IMI had similar effects on the same parameters considered when injected before lisuride, an ergot derivative also active as a central DA receptor agonist. In this case not only SB but also and above all aggressiveness were markedly potentiated, both the signs appearing at doses of lisuride which were “per se” ineffective. Aggressiveness, like SB, was not sex linked and was antagonized by HALO and MOR, but not by MET. IMI alone potentiated the fighting induced by electrical shock, an effect which was abolished by HALO pretreatment. Considering the results obtained as a whole it is submitted that IMI antagonizes PE and SY through a selective blockade of a class of DA receptors, presumably DA presynaptic autoinhibitors, thus potentiating SB and aggressiveness, which involve stimulation of DA postsynaptic receptors.

In this work, we studied the transport properties (thermal and electrical conductivity) of smart fabric materials treated with graphite nanomaterial stacks–acetone suspensions. An innovative and easy method to produce graphite nanomaterial stacks–acetone-based formulations, starting from a low-cost expandable graphite, is proposed. An original, economical, fast, and easy method to increase the thermal and electrical conductivity of textile materials was also employed for the first time. The proposed method allows the impregnation of smart fabric materials, avoiding pre-coating of the fibers, thus reducing costs and processing time, while obtaining a great increase in the transport properties. Two kinds of textiles, cotton and Lycra®, were selected as they represent the most used natural and artificial fabrics, respectively. The impact of the dimensions of the produced graphite nanomaterial stacks–acetone-based suspensions on both the uniformity of the treatment and the transport properties of the selected textile materials was accurately evaluated using several experimental techniques. An empirical relationship between the two transport properties was also successfully identified. Finally, several theoretical models were applied to predict the transport properties of the developed smart fabric materials, evidencing a good agreement with the experimental data.

This work represents an innovative study that, for the first time, explores the possibility to use waste flours to produce thermoplastic polymeric bio-films. To the best of our knowledge, this is the first time that waste flours, derived from bakeries, pizzerias or pasta factories, have been proposed for the production of bio-polymers, as a replacement of neat starch. To this aim, durum waste flour derived from a pasta factory, soft waste flour derived from pizzerias and neat maize starch used as control material were firstly analyzed from dimensional, morphological and chemical points of view. Afterwards, waste flour films were produced by the addition of a nature-based plasticizer, glycerol. Mechanical characterization of the plasticized thermoplastic films, produced by compression molding, evidenced low performances, even in the case of the neat maize starch. In order to improve the mechanical properties, the possibility to include polylactic acid and cardanol-based plasticizer was also investigated. Mass transport properties of all the produced bio-films were investigated by measuring their water vapor permeability and hygroscopic absorption. The durability properties of the bio-films were assessed by accelerated ageing tests, while the bio-degradability of the waste-based films was evaluated by measuring the solubility and the degradation in water. The physicochemical analyses of the novel bio-films evidenced good mechanical properties, specifically, the waste-based films showed a lower hygroscopic absorption and water solubility than those of the blends containing neat starch.

This work is aimed to the development of a self-healing thermoplastic matrix nanocomposite, obtained through the ring-opening polymerization of cyclic butylene terephthalate (CBT) to polybutylene terephthalate (pCBT); a partial polymerization allows obtaining a mixture of CBT and pCBT, being the two materials characterized by a difference in the melting temperature of about 80 °C. Healing of the material requires heating to a temperature higher than melting of CBT, but lower than melting of pCBT; therefore, the molten CBT is able to weld the surfaces of the growing crack, thus restoring mechanical properties. The presence of solid pCBT allows retaining the geometry of the material. In order to produce a partially polymerized material, two different systems were studied: a first one with two catalysts, with different activation temperatures, and a second one with one single catalyst partially intercalated in nanoclay layers. Rheological analysis was used in order to study the viscosity evolution associated with the conversion of CBT to pCBT during thermal treatment. Differential scanning calorimetry (DSC) was used in order to measure the amount of unreacted CBT after processing, and to verify the further conversion of CBT to pCBT during healing. Also, DSC analysis highlighted the structural changes of pCBT crystallinity during healing. Flexural tests were performed on partially reacted pCBT samples, highlighting the relevant effect of the addition of nanoclay on the mechanical properties of the material. Adhesion tests performed after healing evidenced the efficacy of the proposed approach for development of self-healing thermoplastic polymers.

This work is aimed to study the suitability of cardanol and its derivatives as plasticizers for poly(lactic acid), PLA. Differential scanning calorimetry (DSC) was used to assess the plasticizing effectiveness of cardanol (CARD) and its derivatives, cardanol acetate and epoxidated cardanol acetate, comparing the results with those obtained with a commercially available plasticizer, poly (ethylene glycol), PEG, with an average molecular weight of 400 g mol−1. Measurement of the glass transition temperature highlighted that, among the tested cardanol derivatives, neat cardanol is the most effective plasticizer for PLA. In fact, the glass transition temperature of PLA plasticized by CARD is only slightly higher than that of PLA plasticized by PEG. This is attributed to the lower compatibility between PLA and CARD compared to PLA and PEG, as estimated by the interaction radius. Therefore, cardanol could represent a technically valid, economic, and largely available plasticizer for PLA. Moreover, DSC, an X-ray diffraction analysis, showed that, compared to PEG, the addition of CARD involves a limited increase of the rate of crystallization, even in this case, due to its lower compatibility with PLA. Dynamic mechanical analysis showed that, below glass transition, PEG is able to reduce the stiffness of PLA by a higher extent. However, as the temperature increases, retention of the shear modulus of PEG-plasticized PLA is much higher than that of CARD-plasticized PLA. As a consequence, above glass transition, the stiffness of CARD-plasticized PLA becomes lower than that of PEG-plasticized PLA. Therefore, despite its lower compatibility with PLA, CARD can impart to plasticized PLA lower modulus compared to PEG, when the plasticizer content is high enough to reduce the glass transition below room temperature.

This work is aimed to the development and property optimization of cardanol derived plasticizers. To this purpose, different plasticizers were produced though different epoxidation routes, characterized by low toxicological and environmental impact. The plasticizers are characterized by different yield of epoxidation of the alkyl chain double bonds. The properties of the cardanol derived plasticizers were compared to the properties of commercial plasticizers, either phthalates or natural derived. Mechanical properties of soft PVC plasticized by cardanol derivatives were shown to be comparable to those of PVC with commercial plasticizers. The plasticizing efficiency of cardanol derivatives was significantly improved by increasing the yield of epoxidation. Also, mechanical properties performed after ageing showed the excellent stability of the properties of the cardanol derived plasticizer characterized by the higher yield. Evaluation of the property retention index after ageing indicated that such plasticizers showed an improved stability of properties compared to other commercial plasticizer. The results obtained highlight the relevance of an high conversion of the double bonds into epoxies in order to produce high quality plasticizers.

This work is aimed at the development of innovative, easy and cheap methods for the stabilization, inertization and valorisation of the organic fraction of municipal solid waste (OFMSW). For the first time, two original processes for transforming the organic waste into an inert, odorless and sanitized material were here proposed. The first one, called dual step, starts with grinding of the OFMSW, by means of an industrial shredder. After being finely ground, the organic waste was exposed to a sterilization process by means of UV/ozone radiations or thermal treatment (stabilization phase) in order to obtain a complete removal of the OFMSW&rsquo, s bacterial activity. By means of several microbiological analyses, the best sterilization method was chosen. The incorporation in a thermosetting matrix was, then, carried out through mixing the sterilized and finely ground organic waste into a water soluble urea formaldehyde (UF) based resin, with a formaldehyde content less than 1% wt, followed by a thermal treatment for UF-resin crosslinking (inertization phase). An alternative cheaper and easier process, called one step, was also proposed and investigated, by combining the sterilization with the curing thermal process (at higher temperature) of the thermosetting matrix. The preliminary experimental results reported in this paper suggest that both the proposed methods could be considered suitable for the production of high valorized innovative OFMSW-derived panels or bricks that could find application in several fields, such as building or construction materials. Finally, a brief description of the prototype machinery, properly designed for implementing OFMSW stabilization and valorization processes, is reported.

This work is aimed at studying the suitability of polylactic acid (PLA) plasticized by two cardanol derivatives, i.e., cardanol and epoxidized cardanol acetate, in rotational molding, for the production of hollow items. For this purpose, plasticized PLA samples were obtained by melt mixing and then processed by a lab-scale rotational molding equipment. For comparison, poly(ethylene glycole), PEG, and plasticized PLA samples were also produced. Despite the very low cooling rates attained in rotational molding, completely amorphous samples were obtained with neat PLA and PLA plasticized by cardanol derivatives. In contrast, PEG plasticized PLA showed a very high degree of crystallinity, as highlighted by DSC and XRD analysis, which made the extraction of the rotomolded box-shaped specimens impossible. The plasticizing effectiveness of cardanol derivatives was proven by tensile testing of rotational molded prototypes, which highlighted the reduced modulus and strength and improved strain to break, compared to neat PLA. Therefore, efficient toughening of PLA can be attained by the use of the two cardanol derived plasticizers, which involves a significant reduction of the polymer glass transition, as well as a reduced increase of the crystallization kinetic. On the other hand, the reduction of the glass transition temperature due to the addition of plasticizer is responsible for significant crystallization effects even during ageing at room temperature, which involves significant embrittlement of the material.

This work is aimed at studying the suitability of ultra-high molecular weight polyethylene (UHMWPE) fibers for the production of polyethylene homo-composites processed by rotational molding. Initially pre-impregnated bars were produced by co-extrusion and compression molding of UHMWPE fibers and linear low-density polyethylene (LLDPE). A preliminary screening of different processing routes for the production of homo-composite reinforcing bars was performed, highlighting the relevance of fiber impregnation and crystalline structure on the mechanical properties. A combination of co-extrusion and compression molding was found to optimize the mechanical properties of the reinforcing bars, which were incorporated in the LLDPE matrix during a standard rotational molding process. Apart from fiber placement and an increase in processing time, processing of homo-composites did not require any modification of the existing production procedures. Plate bending tests performed on rotational molded homo-composites showed a modulus increase to a value three times higher than that of neat LLDPE. This increase was obtained by the addition of 4% of UHWMPE fibers and a negligible increase of the weight of the component. Dart impact tests also showed an increased toughness compared to neat LLPDE.

The aim of this work is the analysis of the suitability of cardanol derivatives as primary plasticizer for polyvinyl chloride (PVC). Cardanol derived plasticizers (CDP) were obtained by acetylation of cardanol, followed by epoxidation of the side chain double bonds. The developed procedures allowed to achieve high yields of acetylated cardanol, whereas plasticizers characterized by different yields of epoxidation were obtained, according to the used synthesis procedure. Rheological analysis was used in order to study the gelation process of PVC plastisols with CDP. A comparison of commercial phthalate and natural derived plasticizers showed that the CDP are characterized by adequate gelation properties, involving a complete absorption of the plasticizers at relatively low temperatures. The gelation properties showed a strong dependence on the yield of the epoxidation. In particular, lower gelation temperatures, higher plasticizer absorption and faster gelation were observed for higher epoxy content in the plasticizer. Finally, ageing tests were performed on soft PVC produced by the CDP. The weight loss of soft PVC with CDP is comparable to that of commercial plasticizers, particularly at high yields of epoxidation.