Introduction Nowadays, coastal pollution monitoring consists in study environmental media, such as sediments, water or/and biological samples, as mussels. A new challenge started in 2009 with the International Pellet Watch (IPW), proposing the use of resin pellet as no-living passive samplers, in order to avoid long and high-cost preparation samples of coastal environmental media. Positive correlation (Fig. 1) between POPs concentration in mussels and in resin pellet has been proved during IPW [1]. Fig. 1. Correlation between of ?PCBs in mussels (ng/g-lipid) and in plastic pellets (ng/g-pellet) [1]. Resin pellets are the small virgin plastic particles of different polymeric types from which all plastic objects are made. During plastic production processes, industries and factories disperse resin pellets in the environment and most of them arrive in the ocean standing there for a lot of time. Due to their specific weight almost the same of salt water, many of types of pellets floats in the marine microlayer, and many of them and many of them end up on the beaches. As the main POPs (persistent organic pollutants) and linear hydrocarbons absorption takes place in the microlayer where pollutants are most concentrated than in the water column. In this way pellets can sorb hydrophobic substance [2], [3]. The environmental pollution mapping methods proposed within the IPW is based on Endo et al. (2005) observation regarding a correlation between the degradation state of resin pellets (especially the PE ones) and their POPs content. They sustain that a more pronounced coloring (yellowing) of the pellet should indicate a longer residence time in the sea of such particles, and therefore a greater degradation of their polymeric matrix; the longer time spent in the sea also means a greater probability of having absorbed pollutants dissolved there, from which should follow a correlation between more intense coloration and POPs penetrated. This means that, by selecting the darkest pellets present at different sites, it is possible to get an idea of the degree of pollution in that particular area [4], [5]. As Endo et al. (2005) considerations are supported by a very small number of sampled pellets, we decided to undertake an "Italian pellets survey" in order to investigate, with a greater sample number and so a major statistical accuracy, the structural characteristics of beached pellets, trying to understand if exists a correlation between physical/chemical degradation state, their color (yellowing) and the organic pollutant concentrations. Fig 2. On the left: Discoloration of different polymeric matrix of pellets over time [3]. On the right: Digital photos of the raw pellets of standard of bio-plastic (in black), 6 months-aged in seawater (in blue) and 6-months-aged in sandbox reproducing beach conditions (in orange) [5]. Materials and methods We sampled pellets distributed in all the Italian peninsula during spring/summer of 2019, thanks to the contribution of volunteers of Italian NGO Legambiente. At the moment we have analysed pellets collected from Le Grazie Beach, which is located inside La Spezia Gulf, as shown in Fig.3.

Experimental studies in recent years highlight the presence of an increasingly high quantity of microplastics worldwide [1]. The "resin pellets" represent a significant share among the first generation microplastics in the millimeter range (from 1 to 5 mm). They disperse in the environment, even unintentionally, during transport, storage and processing and recent studies show that their content varies from 3% to about 30% of all microplastics surveyed on beaches [2]. A three-years experiment was carried out on a simulated beach and in marine water in Santa Teresa Bay (Gulf of La Spezia, Italy). In detail, special cages have been installed on the underwater observatory, LabMARE coastal station [3], placed at ten meters deep. The submarine station is equipped with a sensor for monitoring environmental parameters, recording data every 10 min. The experiment, aimed at investigating the behavior of plastic items and HDPE, PP, PLA and PBAT pellets, began on March 3, 2020 and is still ongoing. Here, the comparison between the properties of the raw pellets and those placed in the two different environments after six months, is discussed. Through chemical, spectroscopic and thermal analyses (GPC, SEM, FTIR-ATR, DSC, TGA) of granules, variations in color, surface morphology, chemical composition, thermal properties and molecular weight, and polydispersity of materials are analysed to show the different influences of environmental conditions. Acknowledgement: The authors thank the Italian Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta for some of the materials useful for the setup of the experiment, DLTM for the availability of LabMARE coastal underwater platform, Dr. Andrea Bordone and Dr. Giancarlo Raiteri (ENEA) for the temperature data of the seawater, and Dipartimento Polizia di Stato--Centro Nautico Sommozzatori of La Spezia (Italy) for the precious support in sampling activities. The authors also thank the Win on Waste group at Area della Ricerca CNR of Pisa (WoW, https://wow.area.pi.cnr.it/). References: [1] L. Peng, D. Fu, Sci. Total Environ, 698, 134254, 2020. [2] S. Merlino, M. Locritani, G. Bernardi, C. Como, S. Legnaioli, V. Palleschi, M. Abbate, Water, 12, 3389, 2020. [3] https://www.dltm.it/it/news/685-alla-spezia-un-laboratorio-sottomarino-costiero-per-testare-nuove-tecnologie-4.html

Choosing renewable energy from wind, solar, hydro, and biomass sources plays an essential role in reducing emissions and moving the global energy transition forward, as also requested by the European Community. Many national and international projects have been funded and now research activities PNRR-funded are starting to develop materials, components and equipment for the conversion and accumulation, the interoperability of sources, the flexibility and the integration of energy systems. In this direction, various groups belonging to the Institute for Chemical and Physical Processes (IPCF), have based their research activity on both an experimental [1-8] and theoretical [9-10] approach in: synthesis and functionalization of nanostructured materials for electrodes and sensitizers realization of dye-sensitized solar cells development of innovative materials, processes and technologies for the production of hydrogen improvement of reliability, efficiency, flexibility and resilience of the national energy system through a multi-scale computational modeling approach development of machine-learning algorithms and of networks for the construction of smart grids for energy management.

One of the pillars of the circular economy and green chemistry is the recovery and enhancement of waste materials. In the circular economy, a system is established where the products are designed in such a way that the generation of waste is minimal or totally eliminated, implementing a culture in which the product is designed to give it a second useful life, with added value and also the reduction of energy and raw material consumption is maximized [1]. Food industry, in particular, produces huge quantities of these materials that, without a valid reuse process, are destined for waste management with considerable economic and environmental costs. Conversely, reversing the traditional perspective, bio-based waste can become a source of many valuable substances with various applications. The driving force of this type of study is to find more and more uses for those that are basically scraps of industry, the disposal of which would be a considerable expense that would burden production processes. In recent years interest is moving from disposal to waste-valorisation with many advantages, both at the level of innovative products than at the level of waste treatment that at this point become an investment, a potential secondary resource instead of an expense. The valorisation of "the low value residues" for the development of new materials from agri-food waste is one of the many ways to take into consideration. The final stage of a production process becomes the beginning of a new cycle, different and often with unusual outcomes. Here we will show a way to breathe new life into these wastes. Thanks to the fibres and the protein fraction of legumes [2,3], to the cutin extracted from tomatoes [4,5], new materials have been achieved, firstly on a laboratory scale up to the scale-up to make the process industrial. Acknowledgement Marta Project. Sviluppo di una Innovativa MultipiattAforma SmaRt DrifTer - UMV- SAPR Per Indagini MArine. Programma POR CREO FESR TOSCANA 2014-2020. References [1] L. L. del Rio Osorio, E. Flórez-López, C. D. Grande-Tovar, Molecules, 26(2), 515, 2021. [2] L. Ricci, E. Umiltà, M.C. Righetti, T. Messina, C. Zurlini, A. Montanari, S. Bronco, M. Bertoldo, J. Sci. Food Agric., 98, 5368, 2018. [3] S. Bronco, M. C. Righetti, C. De Monte, M. Bertoldo, L. Ricci, P. Cinelli, A. Lazzeri Contributo al "10th Society And Materials International Conference SAM 10", 9-10 Maggio 2016, Roma, con poster dal titolo "Investigation of interfaces polymer/fiber and amorphous/crystal in biocomposite obtained from the valorization of agricultural co-products and by-products". [4] C. De Monte, L. Ricci, Oral communication in Science Colloquia, 11st March 2022 "A new life to industrial biobased wastes: from biopolymers to bioplastics". https://ipcfseminar.wordpress.com/a-new-life-to-industrial-biobased-wastes-from-biopolymers-to-bioplastics/ [5] L. Arrighetti, S. Bronco, C. De Monte, L. Ricci. "È possibile ottenere una bioplastica a partire da scarti agroalimentari?". https://wow.area.pi.cnr.it/bright-2021/

In this paper, we present two novel experimental setups specifically designed to perform in situ long-term monitoring of the aging behaviour of commercial plastic granules (HDPE, PP, PLA and PBAT). The results of the first six months of a three year monitoring campaign are presented. The two experimental setups consist of: (i) special cages positioned close to the sea floor at a depth of about 10 m, and (ii) a box containing sand exposed to atmospheric agents to simulate the surface of a beach. Starting from March 2020, plastic granules were put into the cages and plunged in seawater and in a sandboxe. Chemical spectroscopic and thermal analyses (GPC, SEM, FTIR-ATR, DSC, TGA) were performed on the granules before and after exposure to natural elements for six months, in order to identify the physical-chemical modifications occurring in marine environmental conditions (both in seawater and in sandy coastal conditions). Changes in colour, surface morphology, chemical composition, thermal properties, molecular weight and polydispersity, showed the different influences of the environmental conditions. Photooxidative reaction pathways were prevalent in the sandbox. Abrasive phenomena acted specially in the sea environment. PLA and PBAT did not show significant degradation after six months, making the possible reduction of marine pollution due to this process negligible.

Nell'ambito dell'accordo di collaborazione tra CNR e Scapigliato S.r.l. sulla ottimizzazione del processo di trattamento del sottovaglio del TMB e del digestato mediante sistemi di lombricoltura, a inizio 2022 è stata intrapresa una sperimentazione a livello di laboratorio sul vermicompostaggio di sottovaglio da trattamento meccanico dei rifiuti solidi urbani (RSU) e di digestato anaerobico (D) e loro miscele, anche con altri materiali quali scarto verde e letame. Il processo di vermicompostaggio è stato monitorato dal 22 marzo al 26 luglio 2022.

The process of the development of a citizen science platform on Ocean Literacy designed and implemented during the lock down period of 2020 is described. As restrictions due to the COVID-19 health emergency did not allow researchers to organise public events and field data collection activities related to Ocean Literacy, it was decided to take advantage of this situation by building an online platform to bring Ocean Literacy issues directly into citizens' homes. The massive use of digital tools by all civic communities during this time has enabled both the implementation of this idea and rendering it effective. The pandemic control measures then provided a unique opportunity to focus citizen attention on the collection of household data and information and to highlight the more or less direct connections between citizens' lifestyles and the eco-marine system. Short questionnaires were used to ascertain and highlight citizens' household behaviours and daily attitudes during the lockdown towards water use, seafood consumption and plastic material use and disposal. Data and information were also proposed, collected and analyzed in terms of: general environmental awareness of the respondents, perception regarding their purchasing choices during this particular period, as well as any changes in lifestyles and habits during the lockdown with respect to previous periods. The collected data enabled the improvement of our knowledge on some aspects of people's domestic habits as well as their perception vs. real knowledge about the proposed environmental issues. We also realized that it is increasingly crucial for scientists to directly and extensively involve people and schools in educational and outreach activities and events as a good practice of science-society interaction. But to achieve good results there is a need to develop appropriate communication tools and effective involvement strategies to promote their widespread participation in citizen science projects.

Nella preparazione della matrice organica da avviare al vermicompostaggio, vengono, di solito, considerate tre componenti: il substrato principale, l'eventuale correttivo o additivo per il bilanciamento dei parametri edafici (es. nutrienti, reazione, salinità) e l'agente di supporto (bulking agent). I materiali appropriati per la miscela iniziale vengono determinati sulla base delle caratteristiche del substrato principale da trattare. È considerato correttivo un qualsiasi materiale che, aggiunto in quantità modeste rispetto al substrato principale, serve ad integrare elementi nutrienti (soprattutto azoto) scarsi o addirittura assenti ovvero a condizionare la reazione (pH) della matrice organica. Per raggiungere i requisiti richiesti alla miscela iniziale, è possibile ricorrere a più di un additivo. L'agente di supporto è invece, normalmente, un materiale ligno-cellulosico, da moderatamente resistente a refrattario alla 46 biodegradazione, la cui funzione principale è quella di fornire struttura e porosità? alla miscela di partenza. Spesso l'agente di supporto assolve anche il compito di mitigare l'eccesso di umidità ovvero l'elevata concentrazione (quantità di sostanza organica prontamente degradabile/unità di peso) del substrato principale. In quest'ultimo caso l'agente di supporto funziona anche da correttivo. Nella preparazione della miscela di partenza da sottoporre a vermicompostaggio, è necessario quindi, prima di tutto, considerare il fattore più critico: l'umidità. Una volta calcolato il corretto contenuto di umidità della miscela da avviarsi al compostaggio, l'altro importante calcolo da impostare è quello relativo al rapporto C/N. Carbonio (C), azoto (N), fosforo (P) e potassio (K) sono gli elementi nutritivi principali richiesti da microorganismi e lombrichi coinvolti nel processo di vermicompostaggio. Azoto, fosforo e potassio sono inoltre i principali nutrienti delle piante e, per questo, la loro concentrazione finisce per influenzare anche il valore agronomico del vermicompost. È però soprattutto la quantità di carbonio e di azoto in rapporto bilanciato della matrice iniziale che può? influenzare l'andamento ottimale del processo di vermicompostaggio. In generale, i microorganismi utilizzano, per le reazioni energetiche e la crescita, una quantità? di carbonio circa venti volte superiore a quella di azoto. Ne consegue che è importante la disponibilità? di C ed N in appropriate proporzioni. Le matrici organiche da avviare al vermicompostaggio dovrebbero avere un rapporto C/N compreso tra 20:1 e 30:1 per garantire un andamento ottimale del processo. Il sottovaglio ha un valore del rapporto C/N di 14,4 mentre il digestato di 8,4. Questi valori estremamente bassi possono essere modificati miscelando le matrici iniziali con altri materiali. In particolare, il sottovaglio può essere miscelato con letame che solitamente ha un C/N>30-50. Per quanto riguarda il digestato, invece, un materiale idoneo per apportare carbonio e allo stesso tempo fornire struttura e porosità? alla miscela di partenza può essere la paglia (C/N>80). Anche il biochar può rappresentare un materiale idoneo a migliorare porosità e apportare carbonio al digestato (C/N>50-70). Il biochar è un materiale ligno-cellulosico, da moderatamente resistente a refrattario alla biodegradazione, la cui funzione principale è quella di fornire struttura e porosità alla miscela di partenza. Nel caso del digestato inoltre, l'aggiunta di un materiale ligno-cellulosico è necessaria in quanto, dall'indice di respirazione così come confermato anche dall'indice di germinazione, il digestato presenta condizioni limitanti per lo sviluppo dei microrganismi aerobi.

Waste recycling is a key issue in the European policy for the transition to a sustainable economic system. In this context, the recycling of organic wastes is becoming of great relevance considering that global waste is expected to grow to 3.40 billion tonnes by 2050, approximately 45% of which is organic waste. Given the high proportion of organic matter and nutrient rich profile in organic wastes, these seem suitable for recycling in agricultural applications. Vermicomposting is one of the processes that can be applied to transform organic materials in nutrient-rich compost. Indeed, vermicomposting of organic waste has received increasing worldwide research attention, as demonstrated by the bibliometric analysis reported in Appendix A. On the basis of the scientific results obtained (see Appendix B), vermicomposting is now considered a promising and sustainable technology for the recycling of the organic fraction of municipal solid waste and anaerobic digestate from agricultural and industrial wastes. Some large-scale facilities have already been installed. For example, in January 2021, a state-of-the-art vermicompost facility that can convert 90 tonnes of solid waste into about 24 tonnes of compost was inaugurated on the Mangalore Refinery and Petrochemicals (MRPL) campus in India. Thanks to its properties, vermicomposting could permit to achieve three important societal goals: 1.reduction of waste that ends up in landfills; 2.recycling of waste through the production of a rich "humus; 3.reduction of the use of inorganic fertilizers which are known to furnish readily available nutrients but, at the same time, have negative effects on the soil's physico-chemical and microbial properties and on the environment. Furthermore, the production of vermicompost in a waste management facility allows it to expand its commercial offer with the marketing of the compost and worms exploiting their high reproduction capacity.

Polyvinyl butyral (PVB) is an amorphous polymer employed in many technological applications. In order to highlight the relationships between macroscopic properties and dynamics at a microscopic level, motions of the main-chain and of the propyl side-chains were investigated between Tg - 288o C and Tg + 55o C, with Tg indicating the glass transition temperature. To this aim, a combination of solid state Nuclear Magnetic Resonance (NMR) methods was applied to two purposely synthesized PVB isotopomers: one fully protonated and the other perdeuterated on the side-chains.1 H time domain NMR and1 H field cycling NMR relaxometry experiments, performed across and above Tg, revealed that the dynamics of the main-chain corresponds to the ?-relaxation associated to the glass transition, which was previously characterized by dielectric spectroscopy. A faster secondary relaxation was observed for the first time and ascribed to side-chains. The geometry and rate of motions of the different groups in the side-chains were characterized below Tg by2 H NMR spectroscopy.

Films made of poly(vinyl butyral) (PVB) and antimony-doped tin oxide (ATO) nanoparticles (NPs), both uncoated and surface-modified with an alkoxysilane, were prepared by solution casting at filler volume fractions ranging from 0.08% to 4.5%. The films were characterized by standard techniques including transmission electron microscopy, thermogravimetric analysis and differential scanning calorimetry (DSC). In the polymeric matrix, the primary NPs (diameter ~10 nm) aggregate exhibiting different morphologies depending on the presence of the surface coating. Coated ATO NPs form spherical particles (with a diameter of 300-500 nm), whereas more elongated fractal structures (with a thickness of ~250 nm and length of tens of micrometers) are formed by uncoated NPs. The fraction of the polymer interacting with the NPs is always negligible. In agreement with this finding, DSC data did not reveal any rigid interface and 1H time domain nuclear magnetic resonance (NMR) and fast field-cycling NMR did not show significant differences in polymer dynamics among the different samples. The ultraviolet-visible-near infrared (UV-Vis-NIR) transmittance of the films decreased compared to pure PVB, especially in the NIR range. The solar direct transmittance and the light transmittance were extracted from the spectra according to CEN EN 410/2011 in order to test the performance of our films as plastic layers in laminated glass for glazing.

The book describes the development and commercialization of materials with viscoelastic properties, placing particular emphasis on the scientific and technological differences between plastics and bioplastics. The authors explain how to handle each of the two types of materials and determine the comparative environmental impact of the material life-cycle. The practical values of the overlapping aspects of the two types of materials from technical properties to eco-compatibility are also discussed.

Background and Objective: The use of biopolyesters and natural fibres or fillers for production of biobased composites has attracted interest of various application sectors ranging from packaging to automotive components and other high value applications in agreement with a bioeconomy approach. In the present paper biobased composites were produced by using compostable polymers degradable even in soil and marine water such as polyhydroxyalkanoates with natural fibres or fillers derived by food wastes (legumes by-products) and by wood industry.

The thermal, mechanical, and rheological properties of biocomposites of poly(lactic acid) (PLA) with potato pulp powder were investigated in order to (1) quantify how the addition of this filler modifies the structure of the polymeric material and (2) to obtain information on the possible miscibility and compatibility between PLA and the potato pulp. The potato pulp powder utilized is a residue of the processing for the production and extraction of starch. The study was conducted by analyzing the effect of the potato pulp concentration on the thermal, mechanical, and rheological properties of the biocomposites. The results showed that the potato pulp powder does not act as reinforcement but as filler for the PLA polymeric matrix. A progressive decrease in elastic modulus, tensile strength, and elongation at break was observed with increasing the potato pulp percentage. This moderate loss of mechanical properties, however, still meets the technical requirements indicated for the production of rigid packaging items. The incorporation of potato pulp powder to PLA offers the possibility to reduce the cost of the final products and promotes a circular economy approach for the valorization of agro-food waste biomass.

A linear non-ionic hard-soft segmented polyurethane (PU0) was prepared by the prepolymer synthesis method. The isocyanate terminated prepolymer, formed by a short and rigid aromatic diisocyanate and a long flexible poly(tetramethylene oxide) (PTMO), was chain extended with a piperazine (PIP) diol derivative. The non-ionic polyurethane was then ionized by a post-modification method, i.e. alkylation of the piperazine nitrogen atoms, thus obtaining cationomers with three different ionization degrees, named PU10, PU50, PU80. The polymers were characterized by means of FT-IR spectroscopy, solution and solid state Nuclear Magnetic Resonance (NMR) spectroscopies, Differential Scanning Calorimetry (DSC) and ThermoGravimetric Analysis (TGA). The chemical structure of the obtained polymers and their cationic content was confirmed by solution state 1H NMR. It was found that the methylation occurs quantitatively up to 50% of the PIP nitrogen atoms and that, even if a large excess of methylating agent is used, in our operating conditions a maximum of 80% of the PIP nitrogen atoms are ionized. All the characterization techniques used suggested that an increasing ionization degree induces a better phase separation between hard and soft domains, with a lower amount of diisocyanate units dispersed in the soft phase. In particular, FT-IR showed that the introduction of ionic sites modifies the hydrogen bond network and induces a better aggregation of the rigid units. In addition, DSC showed that (i) the glass transition temperature values of the polymers decrease and tend to that measured for pure PTMO upon increasing ionization; (ii) a crystalline phase due to PTMO packing in ordered structures appears at the highest ionization degrees, similarly to pure PTMO. 1H Time-Domain NMR and 13C solid state NMR revealed an increase in PTMO mobility with increasing ionic content, in agreement with DSC results. The measurements of proton spin lattice relaxation times in both the laboratory (T1) and rotating (T1?) frames allowed limits on the size of the hard domains to be estimated. T1? data hint at a phase demixing effect upon increasing the ionization degree.

BACKGROUNDPea, lentil, faba bean, chickpea and bean proteins are potentially renewable raw materials for bioplastic production that can be obtained from agricultural waste. Plastics are usually processed under heating, and thus thermal stability is a mandatory requirement for the application. In this study, the thermal behavior of several legume protein isolates at different purity degrees was investigated.

Dielectric Spectroscopy (DS) and 1H Fast Field-Cycling (FFC) NMR relaxometry were applied for understanding the dynamic behavior of the amorphous ter-polymer poly(vinyl butyral) (PVB) across the glass transition temperature (Tg = 70C by Differential Scanning Calorimetry). Above Tg, main chain segmental motions (a relaxation) were detected and characterized using both DS and FFC NMR relaxometry. The correlation times extracted by the analysis of DS and FFC NMR relaxometry data agreed within a factor of three and showed a Vogel Fulcher Tammann temperature dependence, with an associated Tg of 69C and a fragility of 155 for PVB glass. Below Tg, a secondary process (b relaxation) was revealed by DS, and was ascribed to reorientations of the vinyl alcohol dipoles due to local twisting motions with an associated activation barrier of 11 kcal mol^-1. The b process was also found to contribute to 1H NMR relaxation above Tg.

The combined use of Dielectric Spectroscopy (DS) and 1H Fast Field-Cycling (FFC) NMR relaxometry allowed a detailed understanding of the dynamic behavior of the amorphous ter-polymer poly(vinyl butyral) (PVB) to be achieved across the glass transition temperature (Tg=70 °C by Differential Scanning Calorimetry). Above Tg, main chain segmental motions (alpha relaxation) were detected and characterized by both DS and FFC NMR relaxometry. The alpha process showed a Vogel Fulcher Tammann temperature dependence, with an associated Tg of 69 °C and a fragility of 155 for PVB glass. Below Tg, DS revealed a beta relaxation ascribed to reorientations of the vinyl alcohol dipoles due to local twisting motions and allowed an activation barrier of 11 kcal/mol to be determined. NMR relaxometry data supported the occurrence of this motion, although 1H relaxation could also be affected by reorientations of propyl side chains.

Bionancomposites frombioplastics and nanoclays are of great interest for packaging, agricultural and other large-volume and niche applications due to their enhanced physical, thermal, mechanical and processing characteristics compared to the parent polymer. In this study, the biodegradable polyester poly(butylene adipate) (PBA) was synthesized by in situ polycondensation catalysed by titanium tetrabutoxide in the presence of the natural Moroccan clay beidellite (BDT). Optimization of the nanoclay exfoliation in the bionanocompositewas achieved by cation exchange of BDTwith cetyltrimethylammonium bromide (CTA) and by selecting the most effective among a range of organically modified xCTA-BDT (x = CTA/BDT equivalent feed ratio). Fourier transform infrared and H-1 NMR spectral and size exclusion chromatographic analyses confirmed the effectiveness of the in situ polymerization, yielding structurally regular PBA with narrow molecular weight dispersity and 7750 < <(M)over bar>(n) < 30 360 gmol(-1), depending on the organoclay load. X-ray diffraction and transmission electron microscopy analyses showed best clay dispersion and homogeneous distribution at 2 wt% 3CTA-BDT. From thermogravimetric analysis and differential scanning calorimetry results the thermal stability of PBA is greatly improved even at 1 wt% 3CTA-BDT, its glass transition temperature is nearly unaffected while crystallinity is increased by the organoclay nucleating action. These results, along with a bionanocomposite hydrophilicity only moderately higher than that of PBA, make this preparation approach particularly promising. (C) 2017 Society of Chemical Industry

Emulsion blending as a new method to combine a water-soluble biopolymer, gelatin, with a synthetic biodegradable elastomer, poly(butylene succinate-co-adipate) (PBSA), was investigated. Blending by wet processing a hydrophilic biopolymer with a hydrophobic synthetic polymer aimed at evaluating the potential for improving the mechanical properties of the biopolymer without affecting its biodegradability. The effect of the variation of blend composition, and of the experimental procedure for the emulsification and the subsequent preparation of cast films from the resulting oil-in-water emulsions was analyzed. In particular, processing temperature, concentration of the precursor solutions (aqueous gelatin and PBSA in dichloromethane, respectively), blending method and post treatment conditions (T, P) affect the quality and stability of the aqueous gelatin emulsion containing PBSA in dichloromethane as the dispersed phase. Control of the aqueous phase viscosity is a key parameter for both the emulsion stability and the morphology of the final heterophasic cast films. In fact, viscosity must be sufficiently low to allow high shear emulsification, but high enough to prevent coalescence among the organic phase droplets. The process conditions optimized for a 80/20 blend were extended to the preparation of blends with 5-30 wt % PBSA. It was found that evaporation of the organic phase must be nearly quantitative before casting to allow the formation of uniform films at any investigated composition of the immiscible polymer blend. In fact, when the films are produced by casting, the presence of residual organic solvent along with too high a viscosity of the aqueous gelatin phase promotes the formation of cavities opening up at the lower film surface as a result of the higher density of CH2Cl2. However, such cavities, internally sheathed with PBSA microbeads precipitated upon evaporation of the organic phase, if smaller than 100 mu m turned out to improve the flexibility of the films.