WEATHERING AND BIODEGRADABILITY OF POLYAMIDE 4,10 AND POLYLACTIDE COMPOSITES WITH MICROFIBRILLATED CELLULOSE (MFC) – THE EFFECT OF SURFACE MODIFICATION OF FILLER WEATHERING AND BIODEGRADABILITY OF POLYAMIDE 4,10 AND POLYLACTIDE COMPOSITES WITH MICROFIBRILLATED CELLULOSE (MFC) – THE EFFECT OF SURFACE MODIFICATION OF FILLER Joanna Pagacz , Agnieszka Leszczyńska * , Krzysztof Pielichowski, Justyna Talanda, Krzysztof Stafin Department of Chemistry and Technology of Polymers, Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, 31-155 Kraków * corresponding author: aleszczynska@indy.chemia.pk.edu.pl Abstract Polymer (polyamide 4,10 and polylactide) composites with unmodified and surface- modified microfibrillated cellulose were prepared by melt homogenization method. Biodegradability and UV weathering of neat engineering polymers and their composites were estimated by recording the changes in chemical composition and morphological features. Application of crystalline cellulose as a nanofiller may result both in acceleration or deceleration of biodegradation depending on the nature of polymer used. Keywords Microfibrillated cellulose, polylactide, polyamide 4,10, weathering, morphology Introduction Cellulose crystal nanoparticles (CCN) can be received from plants’ cell walls, some bacteria and bodies of tunicates. These nanoparticles are characterized by abundance, good structural features controlled by biosynthesis and biodegradability. However, the cellulose nanostructures are positioned in a matrix composed of other carbohydrates, such as lignin, hemicelluloses and pectin, what brings the problem of isolation of