| Autor: |
Coelho, Caroline Correa de Souza, Cerqueira, Miguel Ângelo Parente Ribeiro, Albuquerque, Priscilla B. S., Silva, Otniel Freitas, Vicente, A. A., Cabral, Lourdes Maria Corrêa, Teixeira, J. A. |
| Přispěvatelé: |
Universidade do Minho |
| Jazyk: |
angličtina |
| Rok vydání: |
2016 |
| Předmět: |
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| Popis: |
Cellulose microcrystals (CMC) can be used as reinforcing material in the preparation of composite films. This study aimed to evaluate the effect of CMC in starch and chitosan-based films properties. Starch/CMC and Chitosan/CMC composite films were formulated with 1% (w/v) of biopolymer, 0.25% (w/wbiopolymer) glycerol and 0.1% or 0.2% of CMC. The solutions were prepared at 70◦C during 30 min under stirring and submitted to 45 min of ultrasonication. Afterwards were dried in an air-circulating oven at 30◦C for 24 h. The effect of CMC incorporation was evaluated in respect to the surface morphology on a scanning electron microscope (SEM). Solubility was expressed as percentage of the film dry matter solubilized after 24 h immersion in distilled water, and mechanical properties were measured using a texture analyzer following the guidelines of ASTM D 882-10. X-ray diffraction analyses (XRD) were used to evaluate the crystallinity of the samples. SEM micrographs of films with the incorporation of CMC revealed an irregular structure with high heterogeneity and that the roughness of the surface of the films increased for higher concentrations of CMC. Nevertheless, the surface of starch and chitosan films in the absence of CMC are smooth. Regarding to XRD patterns, it was observed that the addition of CMC leads to the presence of reflection peaks at 2θ=22.5° which are related to the cellulose crystalline structure. The values of solubility in water for films with 0.1% and 0.2% of MCM are statistically lower (p |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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