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This article belongs to the Special Issue Advanced Polymer Nanocomposites II. To prepare nonwoven mats constituted by submicrometric fibers of thermally responsive biopolyurethanes (TPU) modified with multiwalled carbon nanotubes (MWCNT), solution blow spinning (SBS) was used. The TPU was the product of synthesis using poly(butylene sebacate)diol, PBSD, ethyl ester L-lysine diisocyanate (LDI), and 1,3-propanediol (PD) (PBSe:LDI:PD) as reactants. TPU was modified by adding different amounts of MWCNT (0, 0.5, 1, 2, and 3 wt.%). The effect of the presence and amount of MWCNT on the morphology and structure of the materials was studied using field-emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR), respectively, while their influence on the thermal and electric behaviors was studied using differential scanning calorimetry (DSC) and capacitance measurements, respectively. The addition of MWCNT by SBS induced morphological changes in the fibrous materials, affecting the relative amount and size of submicrometric fibers and, therefore, the porosity. As the MWCNT content increased, the diameter of the fibers increased and their relative amount with respect to all morphological microfeatures increased, leading to a more compact microstructure with lower porosity. The highly porous fibrous morphology of TPU-based materials achieved by SBS allowed turning a hydrophilic material to a highly hydrophobic one. Percolation of MWCNT was attained between 2 and 3 wt.%, affecting not only the electric properties of the materials but also their thermal behavior. This research was funded by the Fondos de Investigación de Fco. Javier González Benito, política de reinversión de costes generales, Universidad Carlos III de Madrid [2012/00130/004], the Acción Estratégica en Acción Estratégica en Materiales nanocompuestos multifuncionales, Universidad Carlos III de Madrid [2011/00287/003], and the Project PID2020-112713RB-C22-C21 supported by AEI [Ministerio de Ciencia e Innovación of Spain], the University of the Basque Country (UPV/EHU) and (GIU18/216 Research Group).

Cellulose nanocrystals (CNC) have been studied as rheological modulator in order to improve the printing performance of a novel polycaprolactone-polyethylene glycol (PCL-PEG) waterborne polyurethane urea (WBPUU) based ink for direct ink writing 3D-printing technology. The cellulose nanocrystals are chemically bonded to the WBPU, since they were added during the synthesis of a WBPUU, in order to tune the rheological properties of the ink and thus, improve the printing performances. The WBPUU-CNC inks have been extensively characterized from the rheological viewpoint and have been subsequently used to print different pieces. To determine the capacity of the CNC to improve the printing performance of this type of inks, we establish the relationship between the rheological properties of the inks and their printing viability by an optimal window of compositions of the inks. Additionally, we have measured the mechanical and thermomechanical properties of printed WBPUU-CNC pieces to evaluate the effective reinforcement of in situ incorporated CNC in the WBPUU-CNC inks. The results showed that the addition of CNC accentuates the shear-thinning behaviour, presenting lower tan δ, especially at the lowest CNC contents compared with the matrix, which resulted in inks with excellent printable properties. Moreover, the shape fidelity is increased by the solid-like behavior due to the filler effect of CNC and confirmed by SEM images. Finally, a large increase in Young’s modulus and thermal and thermomechanical stability were observed on the printed pieces that contained only 0.5 wt% CNC compared to the matrix, suggesting the formation of effective interactions between CNC and WBPUU, as corroborated by FTIR, that lead to a greater reinforcement.

The aim of this work was to obtain two biopolyols from the liquid residue resulting from the precipitation of lignin contained in two different black liquors, Eucalyptus globulus organosolv black l...

Bio-based cyclic carbonates are of significant research interest as monomers for non-isocyanate polyurethane (NIPU) synthesis. This research describes the synthesis of a series of five-membered bis(cyclic carbonate)s using bio-based polyether polyols (PO3G) with different molecular weights (250, 650 and 1000 g mol−1) and carbon dioxide as green feedstocks. The utilization of CO2 as a source of carbon in the chemical reaction is in agreement with the sustainable chemical industry. Furthermore, in order to support the green and sustainable polymer chemistry approach, the syntheses were attempted under solvent-free conditions. The implemented synthetic methods are focused on the design of processes and final products that minimize negative environmental impact. Detailed chemical structure analysis of synthesized products was performed using a combination of spectroscopy techniques (ATR-FTIR as well as 1D and 2D NMR techniques), mass spectrometry (MALDI-TOF MS) and chromatography analysis (SEC). The formation of the main product with two terminal cyclic carbonates was confirmed and the formed side products were also identified, characterized and quantified. Finally, as a proof of concept, the synthesized bis(cyclic carbonate)s were successfully used for the preparation of NIPU thermosets. Chemical and mechanical properties of the produced materials suggest their high potential for future applications, e.g. as sound absorbing materials.

In this work, shape-customized scaffolds based on waterborne polyurethane-urea (WBPUU) were prepared via the combination of direct ink writing 3D-printing and freeze-drying techniques. To improve the printing performance of the ink and guarantee a good shape fidelity of the scaffold, cellulose nanocrystals (CNC) were added during the synthesis of the WBPUU and some of the printed constructs were immersed in CaCl2 prior to the freeze-drying process to promote ionic crosslinking between calcium ions and the polyurethane. The results showed that apart from allowing the ink to be successfully printed, obtaining scaffolds with good shape fidelity, the addition of the CNC resulted in a greater homogeneity of the porous structure as well as an increase of the swelling capacity of the scaffolds. Additionally, the CNC has a reinforcement effect in the printed systems, presenting a higher compression modulus as the CNC content increases. In the case of samples crosslinked by calcium ions, a rigid shell was observed by scanning electron microscopy, which resulted in stiffer scaffolds that presented a lower water absorption capacity as well as an enhancement of the thermal stability. These results showed the potential of this type of post-printing process to tune the mechanical properties of the scaffold, thus widening the potential of this type of material. The financial support of the Basque Government within the framework of Grupos Consolidados (IT-1690-22) and the Spanish Ministry of Science and Innovation (MINCIN)—State Investigation Agency (AEI) (PID2019-105090RB-I00/AEI/10.13039/501100011033) is acknowledged.

In order to continue the development of inks valid for cold extrusion 3D printing, waterborne, polyurethane–urea (WBPUU) based inks with cellulose nanofibers (CNF), as a rheological modulator, were prepared by two incorporation methods, ex situ and in situ, in which the CNF were added after and during the synthesis process, respectively. Moreover, in order to improve the affinity of the reinforcement with the matrix, modified CNF was also employed. In the ex situ preparation, interactions between CNFs and water prevail over interactions between CNFs and WBPUU nanoparticles, resulting in strong gel-like structures. On the other hand, in situ addition allows the proximity of WBPUU particles and CNF, favoring interactions between both components and allowing the formation of chemical bonds. The fewer amount of CNF/water interactions present in the in situ formulations translates into weaker gel-like structures, with poorer rheological behavior for inks for 3D printing. Stronger gel-like behavior translated into 3D-printed parts with higher precision. However, the direct interactions present between the cellulose and the polyurethane–urea molecules in the in situ preparations, and more so in materials reinforced with carboxylated CNF, result in stronger mechanical properties of the final 3D parts. Financial support from the Basque Government (Grupos Consolidados (IT-1690-22), Elkartek (KK19-00048)) is acknowledged.

Curcumin and chloramphenicol are drugs with different solubility properties in physiological conditions due to their hydrophobic and hydrophilic structure, respectively. In this work, sodium alginate-cellulose nanofibers (SA-CNF) based inks loaded with curcumin and/or chloramphenicol have been developed for syringe extrusion 3D printing technology. Printability and shape fidelity of the drug-loaded inks were analyzed through rheological characterization. Suitable drug-loaded inks were 3D printed showing shape fidelity, and samples were either freeze-dried or crosslinked with Ca2+ and air-dried to achieve functional pharmaceutical forms with different morphological characteristics. In vitro drug delivery tests were carried out from the resulted forms and it was observed that the release performed faster in freeze-dried than in Ca2+ crosslinked/air-dried ones for all cases, resulting in two different methods for controlling drug delivery over time. The differences in aqueous solubility of the drugs, the different CNF content of the inks and the surface area of the samples also played an important role during drug delivery, involving strategies to control the release over an extended duration.

In this work, polycaprolactone–polyethylene glycol (PCL–PEG) based waterborne polyurethane–urea (WBPUU) inks have been developed for an extrusion-based 3D printing technology. The WBPUU, synthesized from an optimized ratio of hydrophobic polycaprolactone diol and hydrophilic polyethylene glycol (0.2:0.8) in the soft segment, is able to form a physical gel at low solid contents. WBPUU inks with different solid contents have been synthesized. The rheology of the prepared systems was studied and the WBPUUs were subsequently used in the printing of different pieces to demonstrate the relationship between their rheological properties and their printing viability, establishing an optimal window of compositions for the developed WBPUU based inks. The results showed that the increase in solid content results in more structured inks, presenting a higher storage modulus as well as lower tan δ values, allowing for the improvement of the ink’s shape fidelity. However, an increase in solid content also leads to an increase in the yield point and viscosity, leading to printability limitations. From among all printable systems, the WBPUU with a solid content of 32 wt% is proposed to be the more suitable ink for a successful printing performance, presenting both adequate printability and good shape fidelity, which leads to the realization of a recognizable and accurate 3D construct and an understanding of its relationship with rheological parameters. Financial support from the University of the Basque Country (UPV/EHU) (GIU18-216), Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2016-76294R and PID2019-105090RB-I00) and the Basque Government (KK-2019/00048) are gratefully acknowledged. Julen Vadillo wishes to acknowledge both the University of Pau and Pays de l’Adour and the UPV/EHU for his PhD grant.

International audience; This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY; 3D printing has exponentially grown in popularity due to the personalization of each printed part it offers, making it extremely beneficial for the very demanding biomedical industry. This technique has been extensively developed and optimized and the advances that now reside in the development of new materials suitable for 3D printing, which may open the door to new applications. Fused deposition modeling (FDM) is the most commonly used 3D printing technique. However, filaments suitable for FDM must meet certain criteria for a successful printing process and thus the optimization of their properties in often necessary. The aim of this work was to prepare a flexible and printable polyurethane filament parting from a biocompatible waterborne polyurethane, which shows potential for biomedical applications. In order to improve filament properties and printability, cellulose nanofibers and graphene were employed to prepare polyurethane based nanocomposites. Prepared nanocomposite filaments showed altered properties which directly impacted their printability. Graphene containing nanocomposites presented sound enough thermal and mechanical properties for a good printing process. Moreover, these filaments were employed in FDM to obtained 3D printed parts, which showed good shape fidelity. Properties exhibited by polyurethane and graphene filaments show potential to be used in biomedical applications.

Hybrid biobased polyurethane flexible foam composites containing a residue from surf industry (polyurethane powder) as filler and graphite or graphene residue were synthe-sized. It was observed that the addition of the powder at low contents did not modify the final properties considerably, since the cell structure was not compromised. Moreover, the powder increased the capacity of the foams to retain the carbonaceous fillers. The compressive properties of the hybrid foams were not altered with the addition of the graphite and graphene. Finally, hybrid composites showed selective absorption capacity since the presence of the carbonaceous fillers provided the foams oil absorption capacity without modifying the hydrophobic nature of the matrix foams. (C) 2021 The Author(s). Published by Elsevier B.V. Authors thank the University of the Basque Country (UPV/EHU) (GIU18/216 Research Group), the Basque Government (PIBA19-0044 project) and the Provincial Country of Gipuzkoa (DG 19/28 Support Program for the Guipuzcoan Science, Technology and Innovation Network 2019) for the financial support. We also acknowledge the "Macrobehavior-Mesostructure-Nanotechnology " SGIker unit from the UPV/EHU, for their technical support and Olatu S.A. (Gipuzkoa) for providing the PUP. T.C-C. thanks the Provincial Country of Gipuzkoa (2017-BE01-000002-01) and the UPV/EHU (ESPDOC19/41).

Hybrid bionanocomposites with shape-memory behavior are reported. The materials were accessed by combining a polyurethane matrix with a highly renewable carbon content, cellulose nanocrystals (CNCs), and magnetite nanoparticles (MNPs). The integration of the two nanoparticle types resulted in tough materials that display a higher stiffness and storage modulus in the glassy and rubbery state, thus contributing to the structural reinforcement, as well as magnetic properties, reflecting a synergistic effect of this combination. A quantitative characterization of the thermoactivated shape-memory effect made evident that the addition of CNCs increases the shape fixity, due to the higher glass transition temperature (

This paper aims at the utilisation of glycerolysate (Gly) obtained in polyurethane recycling process by means of crude glycerine, which has in its structure hydroxyl end groups that allow for further processing. Polyurethanes (PUs) were synthesised using prepolymer method with the mixture of neat polyol and glycerolysate, in different ratios, with 4,4-diphenylmethane diisocyanate (MDI). The prepolymer was subsequently extended using 1,4-butanediol (BD). The incorporation of glycerolysate caused the crosslinking of obtained polyurethane materials. The crosslink density was calculated from swelling measurements by means of Flory and Rehner equation. The effect of recycled component content on the structure, thermal and mechanical properties were investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and mechanical tests, respectively. Morphology was also analysed by atomic force microscopy (AFM). As the content of recycled component increased, the swelling ratio decreased and simultaneously crosslink density increased, resulting in the increase of glass transition and storage modulus at room temperature. Thermomechanical stability, tensile strength, elastic modulus and hardness of PUs also increased with the incorporation of glycerolysate. Although elongation at break decreased, the recoverable deformation increased with the content of glycerolysate. Morphology reveals the transition from a microphase-separated microstructure to an interconnected hard segments domain structure with the incorporation of glycerolysate. These materials can be applied as protective coatings.

Correction for ‘Synthesis and structural characterization of bio-based bis(cyclic carbonate)s for the preparation of non-isocyanate polyurethanes’ by Kamila Błażek et al., Polym. Chem., 2021, DOI: 10.1039/d0py01576h.

The polyol is a major component in polyurethane formulations and therefore introducing to the formulation recycled polyol (obtained during decomposition process) allows decreasing the usage of pure petrochemical components. In this work, thermoplastic polyurethanes were prepared using various mixtures of a petrochemical macrodiol poly(ethylene-butylene adipate)diol (PEBA) and a recycled glycolysate intermediate, called glycolysate polyol, in a two-step synthesis procedure with 4,4-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD). The glycolysate polyol was obtained during glycolysis process of polyurethane elastomer using ethylene glycol as a decomposing agent. Glycolysate polyol showed a higher hydroxyl value (199 mg KOH g−1) and glass transition temperature (Tg, −50.1 °C) than pure macrodiol (PEBA). The maximum concentration of glycolysate polyol was 25 wt% over the total polyol. Synthesized polyurethanes had similar chemical structure compared to the polyurethane synthesized without glycolysate polyol, confirmed by Fourier transform infrared spectroscopy. On the one hand, higher contents of glycolysate polyol resulted in higher Tg and a slightly lower thermal stability analyzed by thermogravimetric analysis. On the other hand, improved thermomechanical and mechanical properties were obtained in polyurethanes with partial replacement of pure macrodiol.

A mat of fibers with shape memory effect is obtained using commercially available components and a simple electrospinning process. For obtaining this goal, a blend of diglycidyl ether of bisphenol A (DGEBA) and Polycaprolactone (PCL) is electrospun and the obtained mats are cured by UV radiation, avoiding the melting of the PCL component. The cationic photoinitiator based on iodonium salts, used for the first time in the electrospinning process, increases the solution conductivity and consequently the spinnability of the blend. The obtained mats show shape memory properties through several cycles, with shape fixity ratios that range from 95 to 99% and shape recovery ratios of between 88 and 100% respectively.

A commercial kraft lignin (k-lignin) was successfully functionalized by means of the reaction of an isocyanate group from isophorone diisocyanate (IPDI) with hydroxyl groups present in lignin (k-IPDI), for their further incorporation in a flexible polyurethane foam (PUF) formulation. The functionalization was confirmed by FTIR and 13 C NMR, as well as by the OH number determination. It was observed that approximately half of the hydroxyl groups present in k-lignin were functionalized. Afterwards, two series of PUF containing 3, 5 and 10% of k-lignin and k-IPDI were prepared by one-shot free rise polymerization. It was observed that the presence of unmodified lignin decreased the reactivity of the system, yielding to longer foaming stages that required the addition of more catalyst to the system. Apart from that, more rigid foams were obtained with k-lignin than with k-IPDI, as it was observed by DSC and compression force deflection (CFD), which values reflected that the presence of k-IPDI contributed to the formation of more flexible foams. It was also found that the functionalization of lignin contributed to a higher chemical attachment of the lignin to the polyurethane matrix as it was observed by lignin extraction experiments. This chemical attachment was reflected on the stress-strain curves which showed that k-lignin containing foams had higher elastic modulus and higher ability to absorb energy than k-IPDI containing ones, which resulted to be more soft and flexible.

In this work polyurethane elastomers were synthesised by using different mixtures of a petrochemical and glycerolysate polyols and 4,4-diphenylmethane diisocyanate (MDI). Glycerolysate polyol was produced from polyurethane foam decomposition using crude glycerine as a decomposition agent. The structure and thermal properties of obtained semi-product were similar to the polyol used in the synthesis of original foam. Glycerolysate polyol was incorporated into polyurethane formulation as soft segment (SS). Since polyol is one of the major component in polyurethane system (>70%) introducing recycled components leads to lowering of consumption of petrochemicals and valorisation of recycled products. Polyurethane elastomers containing up to 16.4 wt.% of glycerolysate polyol were synthesised, soluble in dimethylformamide (DMF) up to ca. 12 wt.%. The effect of glycerolysate polyol content on the structure and properties was analysed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and mechanical tests. Thermal properties did not worsen after using glycerolysate into polyurethane formulation. A slight increase in glass transition temperature is observed with the incorporation of glycerolysate polyol. Elastic modulus, tensile strength and hardness of polyurethane elastomers increased with recycled polyol content. Moreover they showed high elongation at break values.

Thermoplastic and cross-linked biobased polyurethanes with a renewable carbon content ranging from 78 to 98% were synthesized and characterized. The macrodiol and the diisocyanate used were derived from renewable source, the first from castor oil and the second from fatty acid. Moreover, the chain extenders employed were derived from corn sugar and polysaccharides. The effect of component molar ratios and chain extender and cross-linker structure on the final properties was analyzed. Thermal analysis revealed that polyurethanes are formed by amorphous and crystalline domains. It was also observed that the crystallinity of the material is related to the molar ratio of the components and also their structure. Besides, mechanical properties and morphology were tightly dependent on the overall crystallinity, allowing the synthesis of biobased polyurethanes with tailored properties and high renewable carbon content.

Biobased crosslinked polyurethanes were synthesized and characterized as shape-memory polymers. Both the macrodiol and the diisocyanate were derived from renewable sources; the first one from castor oil, and the second one from l -lysine amino acid. The influence of component molar ratios, crosslink density and maximum elongation on the shape-memory properties was analyzed. The thermal analysis showed that polyurethanes were microphase separated. Though the study of the shape-memory properties, it was seen that shape-memory was influenced by crosslink density. A higher crosslink density led to a greater shape recovery, since crosslinks are the responsible for memorizing the shape of the material. With the increase of maximum elongation, both shape fixity and recovery decreased due to higher amount of crosslink net points were broken. Moreover, the synthesized polyurethanes showed its potential to be used in biomedical applications, according to the preliminary in vitro cytotoxicity assays.

As a consequence of the high production and simultaneous consumption of polyurethanes (PU) a great volume of PU waste is landfilled. In this scenario, suitable and efficient routes for PU waste recycling have been searched for many years. In this work two series of PUs using different recycled PU sources were synthesized: a thermoplastic PU series using a glycolysated polyol obtained from the glycolysis of elastomeric PU waste (chemical recycling) and a PU flexible foam series loaded with PU dust waste created in the shaping of PU surf tables (mechanical recycling). Results showed that the incorporation of recycled components in the formulation improved mechanical properties both in the case of thermoplastic polyurethanes and polyurethane foams. The optimum glycolysated polyol was fixed in 15% over the total polyol weight for thermoplastic PUs. In the case of foams, a maximum of 20% PU dust over the polyol weight was incorporated. We thank the Basque Government (IT-776-13) for the financial support. We also thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF), and Olatu S.A (Gipuzkoa) for providing the PU dust. T.C.-C. thanks the University of the Basque Country (DOCREC17/13) and Provincial Country of Gipuzkoa (2017-BE01-000002-01).

Thermo- and magneto-responsive shape-memory bionanocomposites based on a bio-based polyurethane and magnetite nanoparticles were prepared. Due to the structure of the reactants, the behavior of the polyurethane matrix differs from common polyurethanes, since the soft segment was formed by a diisocyanate and a chain extender, whereas the macrodiol served as hard segment. The influence of the magnetite nanoparticles on the thermal and mechanical properties and the shape-memory behavior was studied. It was observed that magnetite nanoparticles interacted with macrodiol-rich domains and decreased the overall crystallinity of the material, although their presence did not affect the mechanical properties to a great extent. At the same time, the magnetite nanoparticles increased the shape fixity and contributed to shape recovery. The bionanocomposites exhibited magnetic behavior and could be easily heated in an alternating magnetic field, allowing fast and almost complete shape recovery. Preliminary cytotoxicity, hemocompatibility, and cell adhesion analysis suggest that the new materials are benign and potentially useful for biomedical applications.

In this work, segmented biopolyurethanes with thermally-activated shape-memory properties were synthesized and characterized. All the employed starting materials were derived from renewable sources. The macrodiol, which forms the hard segment, was derived from castor oil, while the soft segment was composed of a diisocyanate from the amino acid lysine, as well as a chain extender from corn sugar. The effect of component molar ratios and switching temperature on the shape-memory behavior was analyzed. Thermal analysis of the biopolyurethanes shows a phase separated structure. Programming at different temperatures resulted in shape-memory effects, in which shape fixation and recovery could be attributed to different phases of the physical networks. Increasing the switching temperature, shape fixity values improve, however, it has no significant effect on shape recovery values. In addition, preliminary in vitro cytotoxicity evaluation shows that the synthesized fully biobased biopolyurethane has a non-toxic behavior, showing its potential to be used in biomedical applications.

Rigid polyurethane foams were synthesized by using a vegetable oil-based polyol and 4,4-diphenylmethane diisocyanate prepolymer as the majority of reactives,. The polyol was produced by hydroxylation of crude linseed oil with performic acid generated in situ by the reaction of hydrogen peroxide and formic acid. The characterization by FTIR, H1NMR, iodine and hydroxyl values of the polyol and its comparison with the original linseed oil supports the success of the reaction. The reference foam was subsequently modifi ed by substituting part of the linseed oil polyol with glycerol, diethylene glycol, and a polyethylene glycol (all of them of lower molecular weight than the natural polyol). As was expected, glycerol acts as a crosslinker, increasing density and compression properties of the foams. The analysis of the compression results highlighted the importance of the concentration of the polymeric isocyanate (pMDI) in the initial formulation. The pMDI concentration also played a role in the char formation of the foams according to thermogravimetric analysis. The higher crosslinking density of the glycerol-modifi ed foam resulted in better thermal stability among the different foams. Fil: Calvo Correas, Tamara. University of the Basque Country (UPV/EHU). Department of Chemical and Environmental Engineering, Polytechnic School; España Fil: Mosiewicki, Mirna Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina Fil: Corcuera, M. A.. University of the Basque Country (UPV/EHU). Department of Chemical and Environmental Engineering, Polytechnic School; España Fil: Eceiza, Arantxa. University of the Basque Country (UPV/EHU). Department of Chemical and Environmental Engineering, Polytechnic School; España Fil: Aranguren, Mirta Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina

Fil: Meiorin, Cintia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales; Argentina