Effect of short wavelength UV-irradiation on ageing of polypropylene/cellulose compositions

Polypropylene compositions containing 5-30% cellulose were pre-irradiated (λ=254 nm) and then composted in garden soil in laboratory conditions. The effect of photochemical reactions on the course of further degradation during composting was investigated. Photo- and bio-induced changes in samples were studied using reflectance infrared spectroscopy (ATR-FTIR) and tensile tests. Destruction of surface morphology were also observed by scanning electron microscopy (SEM). It was found that photo- and bio-induced changes in PP/cellulose compositions are accelerated compared to these processes occurring in pure components. The mechanical properties of sample tested are lower than those for PP alone but the influence of cellulose amount on the mechanical strength of compositions is insignificant. ATR-FTIR spectroscopy combined with SEM is very useful for fast estimation of polymer surface changes during environmental degradation.