Alternative plasticizers for the production of thermo-compressed agar films.
Int J Biol Macromol
; 76: 138-45, 2015 May.
Article
en En
| MEDLINE
| ID: mdl-25727746
ABSTRACT
Agar films were produced by thermo-compression using choline chloride (ChCl) as a plasticizer with urea. The three solid components were mixed together with the salt and urea (minor components) added to agar (main component) according to a fixed mass ratio of, respectively, 1.1615. A central composite rotatable design (CCRD) with three parameters, 2(3), was used to evaluate the effects of temperature (X1; °C), time (X2; min) and applied load (X3; kN) of heat-pressing on the maximum tensile strength (TS) of the films (Y; MPa). Mixtures of urea and agar prepared at a mass ratio of 15 did not form homogeneous films suggesting the important plasticizing role of the salt. Heat-pressing the mixtures at more draconian conditions led to much darker and opaque films, with better mechanical resistance (higher values of TS). The most resistant film (â¼ 15 MPa) was obtained at 140°C, 20 min and 176 kN. Selected films, including the optimal, showed similar water sorption profiles and close values of water vapor permeability (â¼ 2.5-3.7 × 10(-9)gm(-1)s(-1)Pa(-1)). The fracture behavior and mechanical properties of the films were greatly affected by additional water plasticization when the films were stored at different conditions of relative humidity.
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Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Plastificantes
/
Temperatura
/
Agar
/
Fenómenos Mecánicos
Idioma:
En
Revista:
Int J Biol Macromol
Año:
2015
Tipo del documento:
Article