TEHRAN (INIC)- Iranian researchers have come up with an effective method in food (particularly for beverages) and pharmaceutical packaging which lengthens preservation time greatly.

Researchers from Sharif University of Technology and University of Tehran in collaboration with their colleagues at Iranian Petrochemical Research & Technology Co. applied nanoclays to synthesize a PET-based nanocomposite which is proved to be capable of reducing gas diffusion rates. As a result, when used in packaging, the compound would show better preservations.

“A PET compatible nanocomposite made of two organoclays, namely nanoline DK2 and Cloisite 15A was synthesized by melt mixing in a same-directional parallel two-screw extruder. Afterwards, some samples were prepared for tensile strength, impact and TEM tests. To examine diffusivity, thin polymer films of 0.1 mm thickness and diameter of 15 cm were prepared by press molding," Alireza Dourbash, one of the researchers, said to the news service of INIC.

The results revealed that the prepared sample were more suitable, compared to pure PET samples, in terms of diffusion. Among the samples, the one containing 1 weight percent of organoclay DK2 exhibited the least diffusivity while the one containing 2 weight percent of organoclay A15 demonstrated more desirable mechanical properties.

Moreover, a slight increase in melting point of the nanocomposites, compared to that of in pure PET samples, was observed.

On the other hand, samples containing less nanoclay (1 and 2 percents) had layered structures and their resistance against impact increased as their nanoclay contents increased.

A detailed report on this scientific research work is available at the Journal of Macromolecular Materials and Engineering, volume 294, pages 68 to 74, 2009.