Artículos de revistas
On the effects of hydroxyl substitution degree and molecular weight on mechanical and water barrier properties of hydroxypropyl methylcellulose films
Fecha
2018-04-01Registro en:
Carbohydrate Polymers. Oxford: Elsevier Sci Ltd, v. 185, p. 105-111, 2018.
0144-8617
10.1016/j.carbpol.2018.01.016
WOS:000424264100012
WOS000424264100012.pdf
Autor
Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Universidade Federal de São Carlos (UFSCar)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
In line with the increasing demand for sustainable packaging materials, this contribution aimed to investigate the film-forming properties of hydroxypropyl methylcellulose (HPMC) to correlate its chemical structure with film properties. The roles played by substitution degree (SD) and molecular weight (M-w) on the mechanical and water barrier properties of HPMC films were elucidated. Rheological, thermal, and structural experiments supported such correlations. SD was shown to markedly affect film affinity and barrier to moisture, glass transition, resistance, and extensibility, as hydroxyl substitution lessens the occurrence of polar groups. M-w affected mostly the rheological and mechanical properties of HPMC-based materials. Methocel (R) E4 M led to films featuring the greatest tensile strength (ca., 67 MPa), stiffness (ca., 1.8 GPa), and extensibility (ca., 17%) and the lowest permeability to water vapor (ca., 0.9 g mm kPa(-1) h(-1) m(-2)). These properties, which arise from its longer and less polar chains, are desirable for food packaging materials.