scholarly journals Poly(Alkylene 2,5-Thiophenedicarboxylate) Polyesters: A New Class of Bio-Based High-Performance Polymers for Sustainable Packaging

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2460
Author(s):  
Giulia Guidotti ◽  
Michelina Soccio ◽  
Massimo Gazzano ◽  
Valentina Siracusa ◽  
Nadia Lotti

In the present study, 100% bio-based polyesters of 2,5-thiophenedicarboxylic acid were synthesized via two-stage melt polycondensation using glycols containing 3 to 6 methylene groups. The so-prepared samples were characterised from the molecular point of view and processed into free-standing thin films. Afterward, both the purified powders and the films were subjected to structural and thermal characterisation. In the case of thin films, mechanical response and barrier properties to O2 and CO2 were also evaluated. From the results obtained, it emerged that the length of glycolic sub-units is an effective tool to modulate the chain mobility and, in turn, the kind and amount of ordered phases developed in the samples. In addition to the usual amorphous and 3D crystalline phases, in all the samples investigated it was possible to evidence a further phase characterised by a lower degree of order (mesophase) than the crystalline one, whose amount is strictly related to the glycol sub-unit length. The relative fraction of all these phases is responsible for the different mechanical and barrier performances. Last, but not least, a comparison between thiophene-based homopolymers and their furan-based homologues was carried out.

2021 ◽  
Author(s):  
Fuyao Zhong ◽  
Mingyu Ma ◽  
Zhuoran Zhong ◽  
Xinrong Lin ◽  
Mao Chen

A covalently cross-linked polyaniline network is synthesized via interfacial Buchwald-Hartwig polymerization/deprotection, enabling the generation of additive/binder-free and high-performance conducting thin-films for energy storage.


2016 ◽  
Vol 2 (2) ◽  
pp. 40
Author(s):  
Concepción Río Vega ◽  
Ana Ribas Sangüesa

ResumenLa fachada autoportante de ladrillo cara vista es el resultado de una profunda reflexión sobre las diferentes soluciones de fachada de ladrillo que se han utilizado a lo largo de la historia. Ha sido promovida por Hispalyt en estrecha colaboración con el Departamento Técnico de Geohidrol S.A., empresa líder en la investigación, fabricación y comercialización de sistemas para cerramientos de fábrica. Cuando se analizan las diferentes soluciones de las fachadas de ladrillo, bajo la óptica de los requisitos del Código Técnico de la Edificación, la fachada autoportante 'STRUCTURA' se manifiesta como la solución óptima por su simplicidad, sus elevadas prestaciones y el bajo coste en recursos auxiliares. La fachada autoportante 'STRUCTURA' se caracteriza porque la hoja exterior del cerramiento se construye totalmente separada del edificio, gravitando sobre sí misma, lo cual permite la disposición de una cámara de aire (ventilada o no) con aislamiento térmico continuo. De esta forma se elimina el puente térmico en el encuentro con los frentes de pilares y forjados, mejorando notablemente el rendimiento higrotérmico del edificio con el fin de cumplir el Documento Básico de Ahorro de Energía (DB HE), cuyos requisitos en la nueva versión aprobada en Septiembre de 2013 han experimentado un sustancial incremento respecto de los contenidos en la versión anterior. Desde el punto de vista de la respuesta mecánica, la fachada autoportante se fundamenta en el aprovechamiento del potencial que tienen los muros de ladrillo cuando se utilizan como soportes de sí mismos. A diferencia de las soluciones convencionales o de las que requieren elementos auxiliares de sostén dispuestos planta a planta, con la solución 'STRUCTURA' el muro de ladrillo se analiza como un elemento activo en el comportamiento estructural, de manera que su propio peso contribuye beneficiosamente en la resistencia frente a las acciones horizontales.AbstractThe self-supporting face brick façade is the result of a profound reflection on the different solutions for the brick façades that have been used throughout history. It has been promoted by Hispalyt in close collaboration with the Technical Department of Geohidrol S.A., leader company in the research, manufacture and marketing of systems for masonry closings. When analyzing different solutions of face brick façade, under the perspective of the technical building code requirements, the self-supporting façade 'STRUCTURA' appears as the optimal solution for its simplicity, high performance and low cost in auxiliary resources. The self-supporting façade 'STRUCTURA' is characterised by the outer leaf of the enclosure being built fully separately from the building, supported on itself, and thus enabling the provision of an air chamber (ventilated or not) with continuous thermal insulation. In this manner thermal bridges on the fronts of pillars and floors are eliminated, noticeably improving the hygrothermal performance of the building in order to comply with the technical building code basic document for energy saving (DB HE), whose requirements in the new version approved in September 2013 have substantially increased with respect to the requirements of the previous version. From the point of view of the mechanical response, the self-supporting façade is based on exploiting the potential that brick walls have when used as a load-bearing structural element themselves. Unlike conventional solutions or those that require additional support devices arranged floor-to-floor, with the 'STRUCTURA' solution the brick wall is analyzed as an active element in the structural behaviour, so that its own weight contributes beneficially to the resistance against horizontal actions.


Author(s):  
Beatriz Robles-Hernández ◽  
Michelina Soccio ◽  
Iker Castrillo ◽  
Giulia Guidotti ◽  
Nadia Lotti ◽  
...  

Poly(alkylene 2,5-furanoate)s are considered as the most attractive and interesting alternatives to replace oil-based terephthalic polymers. These furan-based polyesters can be synthesized using fully bio-based synthetic strategies, allowing to reduce the environmental impact of plastics. At the same time, these polymers have shown outstanding thermal, mechanical and gas-barrier properties. All these results envisage their industrial use in the near future. Now, considering the downscaling of the products’ size towards the nanometer scale, we present a study of the morphology and nanomechanical properties of poly(alkylene 2,5-furanoate) thin films. Using Atomic Force Microscopy, we report the development of nanostructures upon crystallization, following different thermal treatments, for thin films with thicknesses below 200 nm. Moreover, we studied the impact of crystal growth in the nanomechanical properties of these materials. We found that the polymer thin films preserve their excellent mechanical response even in the confined geometry, as proved by the Young’s moduli values close to the GPa, accompanied by high surface stiffness, and low indentation depths. The poly(alkylene 2,5-furanoate) thin films were found to have nanomechanical properties comparable to those of the oil-based poly(ethylene terephthalate), a further evidence that in the future they could replace traditional polymers in several applications.


1999 ◽  
Vol 594 ◽  
Author(s):  
Yinmin Wang ◽  
Richard L. Edwards ◽  
Kevin J. Hemker

AbstractFree-standing rectangular Al thin films have been fabricated using sputter deposition and standard micromachining techniques. Mechanical properties and residual stresses of both asdeposited and annealed Al films were measured by bulge testing. The films were loaded into the plastic deformation regime, and then unloaded and reloaded several times. The pressure and deflection of the thin films were recorded and used to generate stress-strain curves. The planestrain elastic modulus, flow stress and plastic behavior of the Al thin films were used to characterize the mechanical response of these films. The Al films were measured to have a plane-strain modulus that is slightly lower than the literature values for a {111} textured film. The Von-Mises equivalent yield stress was measured to be higher in the annealed films but much more significant strain hardening was observed in the as-deposited films. A plastic hysteresis was observed on unloading and reloading stress-strain curves of the as-deposited Al films but not the annealed films.


2020 ◽  
Author(s):  
Beatriz Robles-Hernández ◽  
Michelina Soccio ◽  
Iker Castrillo ◽  
Giulia Guidotti ◽  
Nadia Lotti ◽  
...  

Poly(alkylene 2,5-furanoate)s are considered as the most attractive and interesting alternatives to replace oil-based terephthalic polymers. These furan-based polyesters can be synthesized using fully bio-based synthetic strategies, allowing to reduce the environmental impact of plastics. At the same time, these polymers have shown outstanding thermal, mechanical and gas-barrier properties. All these results envisage their industrial use in the near future. Now, considering the downscaling of the products’ size towards the nanometer scale, we present a study of the morphology and nanomechanical properties of poly(alkylene 2,5-furanoate) thin films. Using Atomic Force Microscopy, we report the development of nanostructures upon crystallization, following different thermal treatments, for thin films with thicknesses below 200 nm. Moreover, we studied the impact of crystal growth in the nanomechanical properties of these materials. We found that the polymer thin films preserve their excellent mechanical response even in the confined geometry, as proved by the Young’s moduli values close to the GPa, accompanied by high surface stiffness, and low indentation depths. The poly(alkylene 2,5-furanoate) thin films were found to have nanomechanical properties comparable to those of the oil-based poly(ethylene terephthalate), a further evidence that in the future they could replace traditional polymers in several applications.


Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 866 ◽  
Author(s):  
Giulia Guidotti ◽  
Michelina Soccio ◽  
Valentina Siracusa ◽  
Massimo Gazzano ◽  
Andrea Munari ◽  
...  

The present paper describes the synthesis of novel bio-based poly(butylene 1,4-cyclohexane dicarboxylate)-containing random copolymers for sustainable and flexible packaging applications. On one side, the linear butylene moiety has been substituted by glycol subunits with alkyl pendant groups of different length. On the other side, copolymers with different cis/trans isomer ratio of cyclohexane rings have been synthesized. The prepared samples were subjected to molecular, thermal, diffractometric, and mechanical characterization. The barrier performances to O2, CO2, and N2 gases were also evaluated. The presence of side alkyl groups did not alter the thermal stability, whereas it significantly influences the formation of ordered phases that deeply affect the functional properties, mainly in terms of mechanical response and barrier performance. In particular, the final materials present higher flexibility and significantly improved barrier properties with respect to the homopolymer and most polymers widely employed for flexible packaging. The improvement due to copolymerization was more pronounced in the case of higher co-unit-containing copolymers and for the samples with cyclohexane rings in the trans conformation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luke A. Galuska ◽  
Eric S. Muckley ◽  
Zhiqiang Cao ◽  
Dakota F. Ehlenberg ◽  
Zhiyuan Qian ◽  
...  

AbstractIntrinsic mechanical properties of sub-100 nm thin films are markedly difficult to obtain, yet an ever-growing necessity for emerging fields such as soft organic electronics. To complicate matters, the interfacial contribution plays a major role in such thin films and is often unexplored despite supporting substrates being a main component in current metrologies. Here we present the shear motion assisted robust transfer technique for fabricating free-standing sub-100 nm films and measuring their inherent structural–mechanical properties. We compare these results to water-supported measurements, exploring two phenomena: 1) The influence of confinement on mechanics and 2) the role of water on the mechanical properties of hydrophobic films. Upon confinement, polystyrene films exhibit increased strain at failure, and reduced yield stress, while modulus is reduced only for the thinnest 19 nm film. Water measurements demonstrate subtle differences in mechanics which we elucidate using quartz crystal microbalance and neutron reflectometry.


2002 ◽  
Vol 67 (11) ◽  
pp. 1596-1608 ◽  
Author(s):  
Josef Janča

The effect of miniaturization of the separation channel on the performance of thermal field-flow fractionation (TFFF) is substantiated theoretically. The experiments carried out under carefully chosen experimental conditions proved the high performance of the separation of polymers within an extended range of molar masses from relatively low up to ultrahigh-molar-mass (UHMM) samples. The new micro-TFFF allows to achieve high resolution when applying constant field force operation, it makes easy the programming of the temperature drop which is an advantageous operational mode from the point of view of the time of analysis, and it extends considerably the range of perfectly controlled temperature of the cold wall due to a substantial decrease in the heat energy flux compared with standard size channels.


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