Polypropylene based bio-composites for packaging materials: Physico-mechanical impacts of prepared hyper-branched polyamidoamine and gamma-irradiation

Abstract

In an attempt to produce bio-composites that possess good physico-mechanical properties, polyamidoamine (PAMAM) was synthesized and characterized as a multi-nitrogen terminal biocompatible and nontoxic polymeric species. It was mixed at various ratios of 1.0, 2.0, and 3.0% with polypropylene (PP) via Brabender-like apparatus. The prepared bio-composites were exposed to 20 kGy of gamma-irradiation to investigate the influence of ionizing radiation on the fabricated specimens. Parameters of mechanical for instance tensile strength (TS), modulus of elasticity (EM), elongation at break (%), and hardness (Shore D), of bio-composites, were considered. Moreover, the stress-strain curves of the fabricated samples were investigated. Furthermore, FTIR and thermal analysis including TGA and DSC have been investigated. The crystallinity % of all investigated samples was calculated on the basis of DSC measurements. Overall migration of prepared samples has been performed as an applicable study of food packaging. FTIR results revealed the disappearance of the absorption peak at 1730 cm−l of the carbonyl group of polyamidoamine after the formation of PP/PAMAM bio-composites, indicating a successful combination of the PP matrix with polyamidoamine. The incorporation of PAMAM resulted in a steady improvement of the melting temperature (Tm) of the native PP. The thermal stability of PP/PAMAM composition increases with increasing PAMAM and after being exposed to 20 kGy irradiation. Mechanical data revealed that TS of PP increased with PAMAM content up to 3.0%. The development in TS increased from 20 MPa of native PP to 45 MPa of PP/2% PAMAM bio-composites suggesting the superior interaction between the synthetic PAMAM and PP texture. Furthermore, the prepared bio-composite films displayed highly acceptable migration limits.