Carmen Maria Olivera Müller
Universidade Estadual de Londrina
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Featured researches published by Carmen Maria Olivera Müller.
Carbohydrate Polymers | 2013
Marianne Ayumi Shirai; Maria Victória Eiras Grossmann; Suzana Mali; Fabio Yamashita; Patrícia Salomão Garcia; Carmen Maria Olivera Müller
Biodegradable films were produced from blends contained a high amount of thermoplastic starch (TPS) and poly(lactic acid) (PLA) plasticized with different adipate or citrate esters. It was not possible to obtain pellets for the production of films using only glycerol as a plasticizer. The plasticization of the PLA with the esters and mixture stages added through extrusion was critical to achieve a blend capable of producing films by blow extrusion. Adipate esters were the most effective plasticizers because they interacted best with the PLA and yielded films with appropriate mechanical properties.
Carbohydrate Polymers | 2013
Juliana Bonametti Olivato; Marcelo Medre Nobrega; Carmen Maria Olivera Müller; Marianne Ayumi Shirai; Fabio Yamashita; Maria Victória Eiras Grossmann
Tartaric acid (TA), a dicarboxylic acid, can act as a compatibiliser in starch/polyester blends. A mixture design was proposed to evaluate the effect of TA on the properties of starch/poly (butylene adipate co-terephthalate) (PBAT) blown films plasticised with glycerol. The interaction between the starch/PBAT and the TA has a positive effect on the tensile strength and puncture force. Additionally, greater proportions of TA increased Youngs modulus. The starch+PBAT/TA and Gly/TA interactions contributed to a reduction in the water vapour permeability of the films. The inclusion of TA did not change the crystallinity of the samples. Formulations with intermediate proportions of TA (0.8 g/100 g) were shown to produce the best compatibilising effect. This was observed by DMA analysis as a consequence of the perfect equilibrium between the contributions of TA as a compatibiliser and in the acidolysis of starch, resulting in films with a tensile strength of 5.93 MPa, a possible alternative to non-biodegradable packaging.
Materials Science and Engineering: C | 2013
Marianne Ayumi Shirai; Juliana Bonametti Olivato; Patrícia Salomão Garcia; Carmen Maria Olivera Müller; Maria Victória Eiras Grossmann; Fabio Yamashita
Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used.
Journal of Polymers and The Environment | 2015
Marianne Ayumi Shirai; Carmen Maria Olivera Müller; Maria Victória Eiras Grossmann; Fabio Yamashita
Poly(lactic acid) (PLA) and thermoplastic starch (TPS) sheets plasticized with different adipate and citrate esters were produced by a calendering-extrusion process. The incorporation of plasticizers significantly reduced the glass transition temperature and increased the PLA chain mobility thus improving the mechanical properties. Among the plasticizers employed, diethyl adipate significantly increased the elongation of the sheets and slightly increased the water vapor permeability. Micrographs revealed the incompatibility between starch and PLA, and there was no plasticizer phase separation, suggesting that the plasticizer concentration was adequate. The incorporation of adipate or citrate esters improves the mechanical properties and processability of PLA/TPS sheets produced by calendering extrusion at a pilot scale.
Materials Science and Engineering: C | 2014
Juliana Bonametti Olivato; Carmen Maria Olivera Müller; Gizilene M. Carvalho; Fabio Yamashita; Maria Victória Eiras Grossmann
Starch/PBAT blends were produced by reactive extrusion with tartaric acid (TA) as an additive. The effects of TA, glycerol and starch+PBAT on the mechanical, optical and structural properties of the films were evaluated, with formulations based in a constrained mixture design. Tartaric acid acts as a compatibiliser and promotes the acid hydrolysis of starch chains. These two functions explain the observed film resistance and opacity. TA reduced the weight loss in water. Scanning electron microscopy (SEM) images showed that TA reduces the interfacial tension between the polymeric phases, resulting in more homogeneous films. Nuclear magnetic resonance ((13)C CPMAS) and Fourier transform infrared spectroscopy (FT-IR) suggest that tartaric acid is able to react with the hydroxyl groups of the starch by esterification/transesterification reactions, confirming its role as a compatibiliser. The addition of TA results in materials with better properties that are suitable for use in food packaging.
Química Nova | 2014
Rodrigo A. L. Santos; Carmen Maria Olivera Müller; Maria Victória Eiras Grossmann; Suzana Mali; Fabio Yamashita
This study aims to prepare biodegradable films from cassava starch, poly (butylene adipate–co-terephthalate) (PBAT), and montmorillonite (MMT) using blow-extrusion process and analyze the effects of different types and concentrations of MMT on the microstructure, physicochemical, and mechanical properties of the resulting films. The films were produced by blending 30% of PBAT with glycerol (17.5%), starch (49.0–52.5%), and four different types of montmorillonite (Cloisite® Na+, 10A, 15A, and 30B) at two different concentrations (1.75% and 3.5%). All the films prepared in this study showed an increase in the basal spacing of MMT layers. In particular, the films with 10A and 30B showed the highest increase in intercalation basal spacing, suggesting the formation of intercalated composites. The addition of nanoclays decreased the elongation of films. The addition of Cloisite® 10A resulted in films with the lowest WVP values and the highest stability to water adsorption under different RH conditions.
Polimeros-ciencia E Tecnologia | 2015
Ana Paula Bilck; Carmen Maria Olivera Müller; Juliana Bonametti Olivato; Suzana Mali; Maria Victória Eiras Grossmann; Fabio Yamashita
The demand for renewably sourced biodegradable materials has increased the need to produce materials that combine appropriate functional properties at competitive costs. Thermoplastic starch and polyester blends are an interesting alternative to current materials due to the low cost of starch and the functional properties and processability of the resulting blends. Producing thermoplastic starch (TPS) requires using a plasticiser at concentrations between 20 and 30%wt (in relation to starch). Glycerol is the most common plasticiser due to its high plasticising capacity and thermal stability at processing temperatures. The objective of this study was to evaluate glycerol waste from the biodiesel industry, with different degrees of purification, as plasticisers for TPS / poly (butylene adipate-co-terephthalate) (PBAT) blends. Different purities of glycerol produced films with similar mechanical, optical and barrier properties to those made with purified glycerol (99.7%). Therefore, crude glycerol is a renewable alternative plasticiser that reduces the cost of plasticisation by 6-fold.
Polimeros-ciencia E Tecnologia | 2016
Mauro Vestena; Idejan P. Gross; Carmen Maria Olivera Müller; A.T.N. Pires
Whiskers have been used as a nanomaterial dispersed in polymer matrices to modify the microscopic and macroscopic properties of the polymer. These nanomaterials can be isolated from cellulose, one of the most abundant natural renewable sources of biodegradable polymer. In this study, whiskers were isolated from sugarcane bagasse and corn cob straw fibers. Initially, the cellulose fiber was treated through an alkaline/oxidative process followed by acid hydrolysis. Dimethylformamide and dimethyl sulfoxide were used to replace the aqueous medium for the dispersion of the whiskers. For the solvent exchange, dimethylformamide or dimethyl sulfoxide was added to the aqueous dispersion and the water was then removed by fractional distillation. FTIR, TGA, XRD, TEM, Zeta and DLS techniques were used to evaluate the efficiency of the isolation process as well as the morphology and dimensions of the whiskers. The dimensions of the whiskers are comparable with values reported in the literature, maintaining the uniformity and homogeneity in both aqueous and non-aqueous solvents.
Carbohydrate Polymers | 2008
Carmen Maria Olivera Müller; Fabio Yamashita; João Borges Laurindo
International Journal of Food Science and Technology | 2013
Igor F. E. Silva; Fabio Yamashita; Carmen Maria Olivera Müller; Suzana Mali; Juliana Bonametti Olivato; Ana Paula Bilck; Maria Victória Eiras Grossmann