Environmentally friendly films combining bacterial cellulose, chitosan, and polyvinyl alcohol

effect of water activity on barrier, mechanical, and optical properties

Patricia Cazón (Avtor), Manuel Vázquez (Avtor), Gonzalo Velazquez (Avtor)

Povzetek

The interest in developing new materials intended for food packaging based on bacterial cellulose is growing in the recent years. Flexible and transparent films from bacterial cellulose-chitosan-polyvinyl alcohol have shown excellent UV-barrier properties. However, this composite material interacts with ambient moisture modifying its water activity due to its hydrophilic nature. In this work, an extensive study was carried out to evaluate the changes in the properties of these films as a function of water activity. Moisture adsorption isotherm were described by the GAB method. Results showed the plasticizing effect of water molecules increasing the water vapour permeability of the samples from 1.86·10-12 to 1.17·10-11 g/m·s·Pa, the percentage of elongation from 3.25 to 36.55% and the distance to burst from 0.64 to 5.12 mm. The increase of the water activity dropped the tensile strength values from 74.76 to 38.56 MPa, Young’s modulus values from 3133.46 to 30.71 MPa and burst strength to 703.87 g. The values of the UV-barrier were maintained at the wide range of water activity. Consequently, water molecules do not affect the UV-barrier properties of the films.

Ključne besede

GAB model;moisture adsorption isotherms;bacterial cellulose;mechanical properties;UV-barrier properties;moisture content;

Podatki

Jezik:	Angleški jezik
Leto izida:	2020
Tipologija:	1.01 - Izvirni znanstveni članek
Organizacija:	UNG - Univerza v Novi Gorici
UDK:	54
COBISS:	41886723
ISSN:	1525-7797
Št. ogledov:	1739
Št. prenosov:	0
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

URN:	URN:SI:UNG
Vrsta dela (COBISS):	Delo ni kategorizirano
Strani:	str. 753-760
Letnik:	ǂVol. ǂ21
Zvezek:	ǂiss. ǂ2
Čas izdaje:	2020
DOI:	10.1021/acs.biomac.9b01457
ID:	12238549