Photothermal characterization of low density polyethylene food packages

• Main Authors: Poley Luiz H., Siqueira Ana P. L., Silva Marcelo G. da, Vargas Helion, Sanchez Rubén
• Format: Article
• Language: English
• Published: Associação Brasileira de Polímeros 2004-01-01
• Series: Polímeros
• Subjects: Photoacoustic spectroscopy; LDPE; diffusion coefficients
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282004000100007

The present work discuss the applicability of photothermal techniques for determining diffusion coefficients of oxygen and carbon dioxide of commercial low-density polyethylene (LDPE). The methodology involves the monitoring of diffused gas by a photoacoustic analyzer. Diffusion coefficients measured for CO2 and O2 were 2.77 x 10-8 cm²/s and 1.68 x 10-7 cm²/s, respectively. To support the gas diffusion results, thermal properties were studied using photoacoustic spectroscopy and crystallinity was determined using X-ray diffraction. Values obtained for thermal diffusivity and specific heat capacity were 1.65 x 10-3cm²/s and 2.33 J.cm-3K-1, which are in good agreement with values available in the literature for pure LDPE and thus assure reliability of diffusion coefficients values.