Gamma irradiation assisted fungal degradation of the polypropylene/biomass composites

• PP/biomass composites biodegradability under Bjerkandera adusta fungus was investigated.
• γ-irradiation was applied to initiate the degradation of relatively inert PP matrix.
• Young modulus and hardness increased for γ-irradiated/fungal exposed PP biocomposites.
• Melt structure and dynamic viscosity of composites changed after biodegradation exposure.
• Bjerkandera adusta fungus acts on biomass component of composites.

White-rot fungus Bjerkandera adusta has been tested for its ability to degrade some biocomposites materials based on polypropylene and biomass (Eucalyptus globulus, pine cones, and Brassica rapa). γ-irradiation was applied to initiate the degradation of relatively inert polypropylene matrix. The degradation process has been studied by scanning electron microscopy, atomic force microscopy, infrared spectroscopy, contact angle measurements, rheological and chemiluminescence tests. These analyses showed that the polypropylene/biomass composites properties are worsen under the action of the selected microorganism. The formation of cracks and scrap particles over the entire matrix surface and the decrease of the complex viscosity values, as well as the dynamic moduli of gamma irradiated PP/biomass composite and exposed to Bjerkandera adusta fungus, indicate fungal efficiency in composite degradation.