Changes induced by UV radiation in the presence of sodium benzoate in films formulated with polyvinyl alcohol and carboxymethyl cellulose

VILLARRUEL, SABRINA; GIANUZZI LEDA; RIVERO SANDRA; PINOTTI ADRIANA

MATERIALS SCIENCE & ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS

ELSEVIER SCIENCE BV

Año: 2015 vol. 56 p. 545 - 554

0928-4931

This work was focused on: i) developing single and blend films based on carboxymethylcellulose (CMC) and polyvinyl alcohol (PVOH) studying their properties, ii) analyzing theinteractions between CMC and PVOH and their modifications UV-induced in the presence ofsodium benzoate (SB), iii) evaluating the antimicrobial capacity of blend films containing SBwith and without UV treatment.Once the blend films with SB were exposed to UV radiation, they exhibited lower moisturecontent as well as and a greater elongation at break and rougher surfaces compared to thosewithout treatment. Considering oxygen barrier properties, the low values obtained wouldallow their application as packaging with selective oxygen permeability. Moreover, thecharacteristics of the amorphous phase of the matrix prevailed with a rearrangement of thestructure of the polymer chain, causing a decrease of the crystallinity degree. These resultswere supported by X-rays and DSC analysis. FT-IR spectra reflected some degree ofinteraction polymer-polymer at molecular level in the amorphous regions. The incorporationof sodium benzoate combined with UV treatment in blend films was positive from themicrobial point of view because of the growth inhibition of a wide spectrum of microorganisms. From a physicochemical perspective, the UV treatment of films alsochanged their morphology rendering them more insoluble in water, turning the functionalized blend films into a potential material to be applied as food packaging