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Vegetable oils have been largely used as healing agents for self-healing coatings, which in turn, can recover their physical integrity upon damage due to oil film formation resulted of its oxidative polymerization process. Linseed oil (LO) and chia oil (CO) are able to form films because of their air-drying properties and high polyunsaturated fatty acids content. In this work, drying properties of CO and LO with and without cobalt (II) octoate, as a catalyst for the oxidative polymerization, were quantitatively estimated over time by Fourier-Transform Infrared Spectroscopy (FTIR). The CO drying property showed 47% higher than LO and the catalyst has successfully accelerated the oxidative polymerization of both oils in 95%. Microcapsules containing both pure and catalyzed oils were prepared, mixed into epoxy resin, and applied onto AISI 1020 steel samples. Their healing effect was evaluated through a simulated scratch and submitted to electrochemical tests and imaging.

The drying properties and the performance of the chia oil (CO) as a novel healing agent for self-healing coatings are reported in this work, in comparison with linseed oil (LO). The drying properties of both oils were estimated by their respective drying rates (D.R.) between 0 and 500 h by Fourier-transform infrared spectroscopy. The D.R. of CO at 216 h was 47% higher than LO, which was attributed to its higher polyunsaturated fatty acids content. CO and LO were encapsulated in poly(urea–formaldehyde) microcapsules by in situ polymerization in oil-in-water emulsion, showing mean diameters of 20 and 23 µm, respectively. Coatings loaded with 10 wt% of microcapsules were applied onto AISI 1020 steel surfaces. The effect of these drying oils as healing agents for self-healing coatings was evaluated by artificial scratches and measured by potentiodynamic polarization test (PPT) and electrochemical impedance spectroscopy (EIS) techniques. Scratched samples showed an increasing corrosion potential of only 4 h after the scratch simulation, according to the PPT. EIS results showed that coatings containing CO as a healing agent had lower double-layer capacitance (QPE2-Q), suggesting a slight improved self-healing effect compared to LO.

In the past two decades, self-healing coatings have emerged as a potential alternative approach to enhance the life span of structural metal components constantly exposed to aggressive environments. In this work, we aimed to obtain capsules smaller than 1 µm containing an appropriate amount of oil seeking to provide efficient self-healing. A modification in the route of synthesis of self-healing coating capsules is proposed. This modification of a typical synthesis route, which consisted of introducing an additional mechanical agitation step before adding a formaldehyde aqueous solution, was used to entrap linseed oil as a healing agent in poly(urea–formaldehyde). Hence, two synthesis routes were investigated: one involving mechanical agitation at high-speed rotation and another which combines mechanical and ultrasonic agitation. The capsules obtained by agitation had average sizes of 0.35 ± 0.13 and 0.37 ± 0.19 µm and an oil content of 80 ± 2.2 and 77 ± 1.7 wt%, respectively. Both were incorporated, separately, into an epoxy resin matrix, and the composite was applied onto ASTM A36 steel plates for evaluation of healing crack filling performance and accelerated corrosion testing. Scanning electron microscope images showed that the two coatings had a similar healing effect, mainly due to their similar estimated oil content.

Cornstarch was processed on an extruder with glycerol and different contents of urea giving rise to samples named as SGU-0, SGU-1, SGU-5, and SGU-10. The gelatinization enthalpy ΔHgel, calculated by DSC, indicated that the mixture of glycerol and urea seems to better plasticize the starch than glycerol alone. XRD was used to identify the changes in the crystal structure of native starch after extrusion processing. XRD diffractograms indicated the presence of both residual native crystallinity and processing-induced crystallinity. The morphology observed by SEM was compatible with the presence of residual crystals and recrystallization, as suggested by XRD analysis. SAXS experiments pointed out the minute amount of B-type crystallites in the samples with urea, probably due to the hydrophilic character of urea, which contributes to starch hydration.

Antistatic packagings are very important for proper transportation and storage of electronic components since these components can be damaged with electric overloads generated through rubbing. Therefore, the purpose of this study was to develop an innovative material for antistatic packaging with a sustainable character. For this, a blend of recycled poly(ethylene terephthalate) (PET), polycarbonate (PC), and polyaniline (PAni) was prepared by melt extrusion. Samples have a final content of 68 wt% of PET, 29 wt% of PC, and 3 wt% of PAni doped with cobalt (PAni-Co). The properties were determined by differential scanning calorimetry, thermogravimetric analysis, tensile testing, electrical resistivity analysis, and Fourier transform infrared spectroscopy. To the best of our knowledge, no previous work studied the incorporation of PAni-Co in PET/PC blend.

Nanocrystals cellulose (CNC) has been used in studies as biotemplate to improve the electronic properties of conjugated polymers (CP) increasing their molecular orientation. This study demonstrates the in situ grafting of the CNC surface esterified with 3-thiophenetic acid (3TAA) during the oxidative polymerization of 3-hexylthiophene. The surface modification of the CNC was evidenced by the presence of the band with an absorption peak at 1737 cm−1 in the infrared region and the chemical displacement at 157 ppm of the 13C NMR, assigned to ester group carbon. The influence of cellulose nanocrystals in the molecular organization of the CP was studied by Ultraviolet-visible Spectroscopy (UV–vis) and Cyclic Voltammetry (CV). The lower band gap energy and anodic peak potential observed for the nanocomposite elaborated with 10 wt% CNC3TAA suggest the influence of nanocrystals on the increase in planarity of P3HT macromolecular chains, decreasing the energy expenditure in the oxidative process of the conjugated polymer.

The present study describes the influence of the concentration of lignin when used as a filler in polyurethane foam for crude oil sorption. The foams (lignin 0-20wt%) were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis, contact angle and density. The FTIR analysis confirmed urethane linkage formation, showing that the chemical structure of the polymer was preserved, despite the addition of different lignin concentrations. Thermogravimetric analysis showed that the presence of lignin has altered the onset temperature (Tonset) of the foams, decreasing as the concentration of lignin is increased. The contact angle analysis showed a decrease in the hydrophobicity of the foams with increasing lignin concentration. All modified foams showed an improvement in the oil sorption capacity in a PUF/oil/water system, and the PUF-10 showed an improvement of about 35.5% compared to the PUF-blank. The Langmuir isotherm showed a better fit to the data and predicted a maximum oil adsorption of 28.9gg-1 by the PUF-10. The ΔG° value of -4.4kJmol-1 indicated that crude oil adsorption process by PUF-10 was spontaneous. The results of reuse of the PUF-10 showed that oil removal efficiency remained greater than 95% after five consecutive cycles.

The work demonstrates an easy and simple method for obtaining a TiO2 porous ceramic coated with a CeO2 thin film (COTF) on the surface. Replica technique used a 30 PPI polyurethane sponge and TiO2 ceramic suspension. Dip coating technique was used to coat the material surface and cerium polymeric resin synthesis was obtained by polymeric precursors method. Thermal analysis indicated a thermostable material from 500 °C. X-ray diffraction analysis of calcined CeO2, at 600 to 900 °C, resulted in monophasic and crystalline with a fluorite type cubic structure. Scanning electron microscopy made it possible to monitor COTF formation and growth from islands shape to a more homogenous form over 10 depositions.

Polyurethanes are polymers prepared from the reaction between polyfunctional isocyanates and polyols, containing intramolecular urethane bonds. The thermosetting polyurethane (PUR) is a non-biodegradable polymer, that cannot be reprocessed by melting, so that the waste generated becomes an environmental problem. The objective of this study was to produce and characterize thermoplastic polyurethane (TPU) composites incorporated with rigid polyurethane particles through the extrusion process, as an alternative for the reuse of the PUR and improvement of the TPU properties. Extruded composites with 10%, 20% and 30% in weight were thermopressed and had their morphological, thermal and mechanical properties analyzed. The composite with 20% of filler (TPU/PUR20%) presented the best results, with an increase of 117% in the elastic modulus and 79% in the yield stress when compared to the pure matrix (TPU/PUR0%). No additional increment of the mechanical properties was observed to the composite with 30% of PUR (TPU/PUR30%), probably because of the greater heterogeneity of this composite, related to the difficulty of dispersion and distribution of the high content of the PUR particles in the matrix. This study presented a viable alternative for the use and value aggregation of the thermoset polyurethane residue, contributing to minimize environmental impacts and to improve the properties of thermoplastic polyurethane.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Nesse trabalho, as principais variáveis reológicas que influenciam o processo de impressão 3D do tipo Modelagem por deposição de fundido (FDM) foram parametrizadas. Para isso foram produzidas blendas poliméricas com dois polímeros com propriedades reológicas distintas sendo um deles amplamente utilizado no processamento por impressão FDM, o poli(etilenoglicol-co-ciclohexano-1,4-dimetanol tereftalato) (PETG) e o Surlyn 8940® um poli(etileno-co-ácido metacrílico estabilizado com íons sódio) (PE-co-AMA), que demonstra propriedades de autorreparo. Foram preparadas blendas com composição 30%, 50% e 70% em massa de PE-co-AMA. Filamentos foram produzidos em larga escala e possibilitaram a impressão de peças de alta qualidade e com elevadas propriedades mecânicas. As blendas produzidas foram caracterizadas de forma térmica, mecânica, morfológica, reológica e autorreparo. Danos criados nas blendas por indentadores ligados a técnicas de microdureza foram reparados seja parcialmente ou totalmente. As blendas obtidas foram identificadas como blendas imiscíveis e compatíveis, tendo sido relatadas de forma pioneira na literatura, encaixando-se como um produto inovador que poderá, além da impressão 3D FDM, ser usado em diversas aplicações. In this work, the main rheological variables that influence the 3D printing process, Fused Deposition Modeling (FDM), were be parameterized. For this, polymeric blends with two polymers with distinct rheological properties were prepared, one of them being widely used in FDM printing processing, poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG) and the other Surlyn 8940® a poly(sodium ion stabilized methacrylic acid co-acid) (PE-co-AMA), which has self-healing properties. New polymeric blends PETG / PE-co-AMA containing 30%, 50% and 70% by weight of PE-co-AMA were prepared. Filaments were prepared in a large scale with the blends and enabled a successful printing of high quality parts with high mechanical properties. The prepared blends were characterized by thermal, mechanical, morphological, rheological and self-healing tests. Damages created in the blends by an indentation derived from a microhardness test were partially or totally repaired. The obtained novel blends were identified as immiscible and compatible, and can be considered an innovative product that can, in addition to FDM 3D printing, be used in many applications.

No presente trabalho foram preparados onze distintos supercapacitores (nas configurações simétrica e assimétrica) contendo diferentes materiais ativos de eletrodos e eletrólitos do tipo ionogel. O principal foco da pesquisa foi a construção de dispositivos flexíveis que fornecessem altas capacitância e densidades de energia (superiores a 10 Wh.Kg-1), sem comprometimento da ciclabilidade, isto é, que operassem por um grande número de ciclos. As escolhas dos ionogéis foram feitas de modo a possibilitar a construção de supercapacitores (SCs) flexíveis. Foram avaliados três diferentes ionogéis, os quais foram preparados a partir da adição de líquidos iônicos (LIs) a matrizes de poli (liquidos iônicos) -PLIs. Três matrizes de PLIs e três diferentes LIs foram selecionados por possuírem o mesmo ânion e cátions parecidos, a fim de melhorar a compatibilidade desses compostos. Os ionogéis de concentração de 50% (em massa) de LI foram escolhidos por fornecer boas condutividades iônicas e janelas de potencial (2,5V), sem comprometimento da estabilidade mecânica dos géis, permitindo com isso a construção de SCs na configuração tipo sanduíche (eletrodo ¿ ionogel ¿ eletrodo), sem a necessidade de uso de separadores. Para o preparo do ionogel 1 foi usado o PLI [EPIm][FSI] e o LI [EMIm][FSI]. Já para o ionogel tipo 2, usou-se o PIL [EPIm][TFSI] e o LI [EMIm][TFSI]. Por sua vez, no ionogel tipo3, foram empregados o PLI [A2M2Am][TFSI] e o LI [MPPy][TFSI]. O ionogel tipo 1 foi o que forneceu maiores valores de condutividade iônica. Os ionogeis 1 e 2 exibiram aspecto gelationoso, proporcionando boa aderência aos materiais dos eletrodos e assim, possibilitando o preparo de SCs flexíveis. Em contrapartida, o ionogel 3, um filme de aspecto ceroso, promoveu o descolamento dos materiais do eletrodo dos coletores correntes, sendo portanto, inadequado para a construção de dispositivos flexíveis. Os materiais ativos dos eletrodos foram: (i) nanotubos de carbono de paredes múltiplas funcionalizados (f-MWCNT), (ii) óxidos de grafeno reduzido (r-GO) e (ii) nanocompósitos (r-GO:f-MWCNT), sendo estes dois últimos sintetizados via redução com hidrazina. A composição dos nanocompósitos baseou-se em dados da literatura que indicava que nesta concentração, os CNT atuariam como espaçadores entre as folhas de r-GO, proporcionando uma maior área superficial para a formação da dupla camada elétrica na interface eletrodo/eletrólito. Os SCs foram preparados com esses eletrodos na configuração simétrica, isto é, ambos os eletrodos de mesmo material e também assimétrica com eletrodos distintos (um eletrodo de r-GO e outro de f-MWCNT). Os dados da caracterização eletroquímica mostraram que o supercapacitor assimétrico (r-GO ¿ Ionogel 1 ¿ f-MWCNT) apresentou o melhor desempenho eletroquímico fornecendo altos valores de capacitância, densidade de energia e de potência, com pouco variação desses parâmetros ao longo de 2000 ciclos de operação. Neste trabalho, destaca-se duas contribuições inéditas importantes ao estado da arte de supercapacitores: (i) desenvolvimento de eletrólitos géis do tipo PLI/LI (ionogéis tipo 1 e 2) de alta aderência aos materiais do eletrodo (contribuindo para diminuição da resistência de contato) e (ii) descrição completa do comportamento dos diferentes supercapacitores sólidos e flexíveis desenvolvidos com determinação simultânea da voltagem das células e dos potenciais de cada eletrodo. In the present work, eleven different supercapacitors (in the symmetric and asymmetric configurations) were prepared containing different active materials for the electrodes and ionogel type electrolytes. Themain focus of the research was the construction of flexible devices that provide high capacitances and energy densities (greater than 10 Wh Kg-1), without compromising the cyclability. The ionogels choicewas made in order to allows the construction of flexible supercapacitors (SCs). Three different ionogels were evaluated, which were prepared with the addition of ionic liquids (ILs) to poly (ionic liquids) matrices - PILs. Three matrices of PILs and three ILs were selected to have the same anion and similar cations in order to improve the compatibility between these compounds. The ionogels with 50wt% of IL were chosen once they provide good ionic conductivities and potential windows (2.5V), withoutcompromising the mechanical stability of the gels, thus allowing the construction of SCs in the sandwich configuration (electrode|ionogel|electrode) without the need of separators. For the preparation of ionogel 1 the PIL [EPIm] [FSI] and the IL [EMIm] [FSI] were used. For type 2 ionogel, the PIL [EPIm] [TFSI] and the IL [EMIm] [TFSI] were employed. In the type 3 ionogel, the PIL [A2M2Am] [TFSI] and the IL[MPPy] [TFSI] were chosen. The type I ionogel provided the highest values of ionic conductivity. The ionogels 1 and 2 exhibited gelationous appearance, providing good adhesion to the electrode materialsand thus, making possible the preparation of flexible supercapacitors. In contrast, ionogel 3, a waxy-like film, promoted detachment of electrode materials from current collectors, and it is therefore unsuitablefor the construction of flexible devices. The active materials of the electrodes were: (i) functionalized multi-walled carbon nanotubes (f-MWCNT), (ii) reduced graphene oxides (r-GO) and (ii) nanocomposites (r-GO: f-MWCNT). The composition of the nanocomposites was based on data from the literature that indicates that in this concentration the CNTs would act as spacers between the sheets of rGO, providing a larger surface area for the formation of the electrical double layer in theelectrode/electrolyte interface. The supercapacitors were prepared with these electrodes in the symmetrical configuration, ie both electrodes of the same material, and also in the asymmetric one with different electrodes (one electrode of r-GO and another electrode of f-MWCNT. The electrochemical characterization data showed that the asymmetric supercapacitor (r-GO|Ionogel 1|f-MWCNT) presented the best electrochemical performance providing high capacitance, energy and power densities, with little variation of these parameters over 2000 operating cycles. In this work, two important new contributionsto the state of the art of supercapacitors are highlighted: (i) the development of gel electrolytes of type PIL/IL (ionogels types 1 and 2) with high adhesion to the electrode materials (decreasing the contactresistances) and (ii) complete description of the behavior of the different solid and flexible supercapacitors with simultaneous determination of the voltage of the cells and the potentials of each electrode.