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Biodegradable and potentially biobased polyesteramide oligomers (PEA-Pro), obtained from melt condensation of sebacic acid and 3-amino-1-propanol, were characterized by nuclear magnetic resonance (NMR), matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrometry/mass spectrometry (MALDI-TOF/TOF-MS/MS), thermogravimetric analysis (TGA), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). NMR analysis showed the presence of hydroxyl and amino terminal groups as well as carboxylic groups of the sebacate moiety. Hydroxyl and carboxyl termination had the same abundance, while the amine termination was 2.7-times less frequent. Information regarding the fragmentation pathways and ester/amide bond sequences was obtained by MALDI-TOF/TOF-MS/MS analysis performed on sodiated adducts of cyclic species and linear oligomers. Different end groups did not influence the observed fragmentation. Three fragmentation pathways were recognized. The β-hydrogen-transfer rearrangement, which leads to the selective scission of the –O–CH2– bonds, was the main mechanism. Abundant product ions originating from –CH2–CH2– (β–γ) bond cleavage in the sebacate moiety and less abundant ions formed by –O–CO– cleavages were also detected. TGA showed a major weight loss (74%) at 381 °C and a second degradation step (22% weight loss) at 447 °C. Py-GC/MS performed in the temperature range of 350–400 °C displayed partial similarity between the degradation products and the main fragments detected in the MALDI-TOF/TOF-MS/MS experiments. Degradation products derived from amide bonds were related to the formation of CN groups, in agreement with the literature.

In this work, the amount of PE contained in complex biodegradable polymer blends and in carrier bags claimed to be compostable was determined by thermogravimetry analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Since February 2016, the method has been regularly applied and further extended to check the presence of PE in more than 60 carrier bags certified as compostable and has contributed to reveal the incidence of illegal carrier bags on the market. Analyses were commissioned by Legambiente, private companies and laboratories.

In this paper, the amount of polyethylene (PE) contained in complex biodegradable polymer blends and in carrier bags claimed to be compostable was determined by thermogravimetry analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). To validate the method, polymer blends based on polylactide (PLA), poly(butylene adipate-co-butylene terephthalate) 53/47 (PBAT), native starch (NS), and calcium carbonate, with known amount of PE ranging from 0 to 10%, were prepared by melt mixing. Py-GC/MS parameters were optimized. In the first step at 400 °C, pyrolysis products originated from thermal cracking of PLA, NS and PBAT were detected. In the second step carried out at 500 °C, triplet peaks characteristic for PE, consisting of α,ω-dienes, α-alkenes and n-alkanes, were revealed together with some signals related to PBAT. TGA under nitrogen atmosphere was used to determine the amount of PE in the blends. An overestimation of about 1.2%, constant for all the blends, was revealed. The overestimation was attributed to the partial overlapping of one of the steps of degradation of the commercial PBAT and that of PE. Additionally, the analytical approach was applied in the characterization of carrier bags claimed to be compostable, recovered directly from the market. The correct determination of the composition of these biodegradable blends is important and crucial to comply with the compostability standard EN 13432-2000. According to this standard, each significant organic constituent of the packaging material must be biodegradable. “Significant” means any constituent present in more than 1% of dry weight of that material. This implies that maximum allowed PE concentration that can be detected in a compostable blend is 1%. In two commercial carrier bags, TGA revealed a component with a degradation temperature of about 455 °C corresponding to that of PE. The relative weight loss percentages of these two carrier bags have been estimated 7.6 and 14%. Optimization of the Py-GC/MS conditions allowed identifying its chemical structure. In fact, the Py-GC/MS at 500 °C provided a pyrogram that was a fingerprint for PE with triplets corresponding to linear chains of α,ω-dienes, α-alkenes and n-alkanes with chain lengths in the range of 9–36 C atoms. Overall, the results show that the combination of TGA and Py-GC/MS can be applied with practical implications.

A new test has been developed to determine gel strength and, at the same time, fracture and compression parameters. By using an especially designed probe and standard gelatin gels, we have set up a method to assess gel strength, the cut resistance, simulating a teaspoon, as well as food consistency and chewiness, just in one experiment. In particular, hydrogels of different Bloom degrees, ranging from 90 to 300, were prepared. Gel strength, fracture and compression properties of gelatins were evaluated by a new 3D printed device. A cylindrical-shaped tool and a concentric piston were obtained by means of 3D-printing technology and combined for a fracture/compression test. A device for the classical Bloom test was 3D printed and used for gel strength measurements to find a correlation parameter. The cylindrical-shaped tool has been designed in order to expose to the gelatin surface the same contact area of the classical Bloom probe. Additionally, the optimized test was applied to commercial edible gelatins. The influence of temperature and flavors on gelatin properties was investigated.

The laser-induced degradation on a poly(lactide) (PLA) for medical device applications was studied. PLA films were cut by ultrashort-laser pulses (ULP), a manufacturing process advantageous for medical applications. In fact, heat transmission to the region surrounding the cuts is limited, so that the cuts are precise and the effects on the regions around the cuts are small. However, degradation induced by ULP can occur and compromise the properties of the polymer samples. As a consequence, PLA films, before and after the ULP cuts, were analyzed by NMR, MALDI, ESI MS and SEC. NMR spectra revealed the presence of olefin end groups due to a ?-H abstraction mechanism. Several signal related to different degradation pathways were highlighted by ESI MS.

In this study, we carried out the structural and thermal characterization of a medical-grade poly (lactide) (PLA) by SEC, TGA, DSC, NMR, ICP-MS and Py-GC/MS. Moreover, we investigated the laser-induced degradation occurring when ultrashort laser pulses (ULP) were employed to cut extremely thin polymer films prepared by solvent-casting. ULP polymer cutting technology is an interesting manufacturing process for its advantages in potential medical applications. In fact, heat transmission to the region surrounding the cuts is limited, so that the incisions are precise and the effects on the regions around them are small. In this way, the need for post-processing is reduced and ULP cutting becomes interesting for industrial applications. However, degradation induced by ULP may occur and compromise the properties of the polymer samples. To investigate this possibility, portions of PLA films, ultrashort laser cut (ULC) and uncut, were analysed by SEC, DSC, NMR and FTIR. Furthermore, PLA oligomers were studied by ESI-MS. Both SEC and NMR showed a decrease in the molecular weight. FTIR, ESI-MS and NMR spectra revealed the presence of olefin end groups originated from a β-H transfer mechanism, induced by heat and/or light (Norrish II mechanism). Additionally, the inspection of the ESI mass spectra highlighted the cleavage of ester bonds related to the Norrish I type mechanism, undetected by the other techniques.

During last decades, implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their release in a specific site. Acrylic polymers have obtained growing interest in biomedical applications for their biocompatibility and chemical properties that make them extremely versatile. In this work, we focused on the realization of polymeric systems for controlled and sustained release of betamethasone 17,21-dipropionate (BDP), a corticosteroid drug, in the treatment of the posterior eye diseases (PED). The investigated DDS were made of opportunely designed methacrylic block copolymers. Different series of methylmethacrylate/2-hydroxyethylmethacrylate (MMA/HEMA) block copolymers, with various monomeric compositions (20-60 mol% HEMA), were synthetized by Atom Transfer Radical Polymerization to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymers were characterized by nuclear magnectic resonance, size exclusion chromatography, and differential scanning calorimetry. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. In particular, PMMA-b-PHEMA with 47 mol% of HEMA showed the best release profile to achieve the therapeutic reference dose, used in the treatment of PED (1-3 mu g/day), up to four months. Additionally, intraocular inserts with different shapes were prepared using silicon molds made by means of a 3D printer. POLYM. ENG. SCI., 57:570-578, 2017. (c) 2017 Society of Plastics Engineers

For food packaging, plastic materials display large appeal, mostly due to their versatility, mechanical, optical and barrier properties. However, polymeric materials play an important role in many environmental concerns and in the waste management issue. Compostable bioplastics represent today alternative materials designed for a lower environmental impact. In this work, a biobased compostable packaging, constituted by PLA Ingeo container and NatureFlex film, was evaluated for fresh-cut cherry tomato. A comparative analysis was accomplished using traditional packaging materials, i.e. PET container and PP film. Structural stability under food contact conditions, mechanical and physical-chemical properties were investigated before and after sterilization treatment by UV irradiation. In particular, mechanical properties, oxygen permeability, wettability, overall chemical migration test, with ethanol 50 % simulation liquid, were determined. Additionally, biological oxygen demand (BOD) at 20°C and disintegrability tests at 58°C were carried out to establish the influence of UV sterilization on biodegradability. A low effect of UV treatment on mechanical properties and on BOD was revealed. Oxygen barrier property of NatureFlex film, higher than that of PP, was increased by UV irradiation. Overall, data showed that the biobased compostable packaging for a prolonged shelf-life of fresh-cut cherry tomato has better properties that are enhanced by UV treatment.

Report finale (Prot CNR-IPCB n° 0000457 del 17/02/2016) sull'attività "Sviluppo di matrici polimeriche non-biodegradabili per il rilascio controllato di farmaci cortisonici" svolta, dal 15/9/2011 al 31/12/2015, nell'ambito del progetto PON01_00074 "Dispositivi ad alto contenuto tecnologico per il settore biomedicale" (DIATEME)

Rapporto tecnico (Prot. CNR-IPCB N° 1543 del 20/05/2016) relativo alla determinazione di polietilene in manufatti dichiarati biodegradabili e compostabili, secondo metodica pubblicata in P. Rizzarelli et al. / Journal of Analytical and Applied Pyrolysis 117 (2016) 72-81, nell'ambito del Contratto di Prestazione di Servizi Stipulato con LEGAMBIENTE O.N.L.U.S., via Salaria 403, 01990 Roma (Prot. CNR-IPCB N° 0000577 del 26/02/2016)

Report finale (Prot CNR-IPCB n° 0000955 del 04/04/2016) sull'attività 3.3.1 "Ricerca e sviluppo di packaging a permeabilità controllata per il confezionamento di prodotti di IV gamma" svolta, dal 01/10/2012 al 31/12/2015, nell'ambito del progetto PON02_00451_3361909 "Utilizzo integrato di approcci tecnologici innovativi per migliorare la shelf-life e preservare le proprietà nutrizionali di prodotti agroalimentari" (SHELF-LIFE). Sono state testate le performance di film microforati e film biodegradabili e compostabili, a base di cellulosa (Natureflex E946) per il confezionamento di prodotti di IV gamma (patate, carciofi e pomodori). L'attività ha dato avvio a collaborazioni con il Dipartimento d'Agraria dell'università di Catania e con colleghe del CNR IVALSA. I dati sono stati oggetto di quattro pubblicazioni su riviste scientifiche e di comunicazioni a convegni internazionali. I risultati più significativi raggiunti, in collaborazione con la Dott.ssa Patané (IVALSA), hanno riguardato il confezionamento dei pomodorini da serbo di IV gamma con un packaging biodegradabile e compostabile. Per il confezionamento dei pomodorini da serbo di IV gamma è stato selezionato e testato il film (spessore 30 µm), biodegradabile e compostabile, NatureFlex(TM) E946 che è stato fornito ai partner e messo a confronto con un materiale tradizionale a base di polipropilene (PPCoex, spessore 20 µm). Le proprietà meccaniche dei film selezionati sono state determinate in accordo con le normative ISO 527-1:1996 e ISO 527-3:1997. I test sono stati condotti e eseguiti sui provini orientati sia parallelamente sia ortogonalmente alla direzione di estrusione. I dati ottenuti hanno evidenziato come il NatureFlex(TM) E946 abbia proprietà meccaniche competitive con quelle del PPCoex e idonee per il confezionamento dei pomodorini di IV gamma. Al film compostabile sono state abbinate delle vaschette in PLA Ingeo a sezione circolare, anch'esse biodegradabili e compostabili. I pomodorini confezionati con il film tradizionale, PPCoex, sono stati posizionati in vaschette in PET, riciclabile. Sia i film che le vaschette, prima del confezionamento, sono stati sottoposti a cicli di sterilizzazione sotto cappa UV per 24 h. I pomodorini sono stati sottoposti a trattamento con ipoclorito di sodio o con ipoclorito di sodio e cloruro di calcio. Le prove di SHELF-LIFE sono state effettuate a 4°C e a tempi differenti (0, 5, 12 e 18 giorni) sono stati monitorati il calo ponderale, il residuo secco, il residuo ottico (°Brix), i fenoli, il PH, le proprietà antiossidanti, le condizioni igenico-sanitarie e gli scambi gassosi. Le proprietà barriera del NatureflexTM E946 all'ossigeno (OTR 55 ml ?m/m2 24h - 8°C 70% RH) e all'anidride carbonica (95 ml ?m/m2 24h - 8°C 70% RH) hanno garantito una migliore conservazione del prodotto fino a 18 giorni, mantenendo le proprietà nutrizionali e limitando lo sviluppo microbico. La maggiore permeabilità al vapore acqueo del materiale biodegradabile (200 g/m2 24h - 25°C 75% RH), sebbene abbia comportato un maggiore calo ponderale, ha evitato la formazione di condensa di goccioline di acqua sulla superficie (effetto antifog), che è auspicabile per una buona conservazione del prodotto. La condensa dell'umidità sulla superficie interna della confezione comporta, oltre a un decadimento visivo poco gradito al consumatore, la formazione di gocce che possono costituire il sito di crescita microbica. Infatti, dopo 18 giorni di conservazione a 4°C, sui pomodorini confezionati con un packaging tradizionale si osserva la comparsa di muffe mentre il prodotto imballato nel sistema biocompostabile risulta inalterato dal punto di vista microbico e nutrizionale.

Report finale (Prot CNR-IPCB n° 0000954 del 04/04/2016) sull'attività 3.2.1 "Ricerca e messa a punto di film polimerici biodegradabili multistrato ad effetto barriera" svolta, dal 01/10/2012 al 31/12/2015, nell'ambito del progetto PON02_00451_3361909 "Utilizzo integrato di approcci tecnologici innovativi per migliorare la shelf-life e preservare le proprietà nutrizionali di prodotti agroalimentari" (SHELF-LIFE). Le performance di tre film a base di cellulosa, commercializzati con il nome di NatureFlex(TM) (Innovia), denominati N948, NK e NVR, metallizzati e non, tutti certificati come biodegradabili e compostabili in accordo con la normativa EN 13432, ad elevate proprietà barriera verso i gas e all'umidità, e di due film a base di acido polilattico (PLA), il Nativia(TM) NTSS e il PLA09 Oxaqua®, sono state conforntate con quelle di materiali da imballaggio tradizionali impiegati dall'azienda siciliana Dolfin, per il confezionamento, primario e secondario, di prodotti a base di frutta (puree). Sono state valutate la stabilità termica, le proprietà meccaniche e la resistenza delle saldature. Sono state effettuate delle prove di confezionamento su impianto presso l'azienda Dolfin ed è stata valutata la shelf life dei prodotti.

Mediante MALDI-TOF/TOF-MS/MS (matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry) sono stati studiati i meccanismi di frammentazione di una poli(estere ammide) ottenuta, per condensazione allo stato fuso, da acido sebacico e 3-ammino-1-propanolo. L'analisi è stata eseguita selezionando gli addotti sodiati di catene cicliche e lineari con diversi gruppi terminali. Sono stati individuati tre meccanismi di frammentazione (?-hydrogen-transfer, scissione dei legami -CH2-CH2- (?-?) nell'unità sebacica e dei legami -O-CH2), che non sono influenzati dalla natura dei gruppi terminali dello ione precursore. La concomitante presenza negli spettri MS/MS, degli oligomeri amino-alcool terminati da entrambe le parti, di frammenti originati da sequenze estere/estere, ammide/ammide e estere/ammide, ha permesso di escludere una distribuzione alternata di legami esterei e ammidici in catena.

Sono state effettuate prove di disintegrabilità nel suolo (Soil burial test) a differenti temperature su campioni, foto-ossidati e non, a base di polimeri biodegradabili forniti dal contraente (Irritec SpA).