Influence of the compatibilizing agent on permeability and contact angle of composites based on polylactide

The aim of the work was to determine the impact the quality and quantity of nanofillers and the presence of a compatibilizing agent have on the surface‐free energy (SFE) and barrier properties of the polylactide (PLA)‐based nanocomposites. The PLA nanocomposites were prepared by extrusion using a twin‐screw extruder. Two types of nanoclays, Nanofil2 (N) and Montmorillonit K10 (S), were used as nanofillers. Poly(ε‐caprolactone) (K), acting as the compatibilizing agent, was introduced into the PLA‐nanofiller system in order to improve the nanoclay dispersion in the PLA matrix. The SFE was monitored by measurement of contact angle of the composites with water and methylene iodide. The barrier properties were investigated by analyzing of diffusion water vapor and oxygen. It has been established that introduction of nanofillers and a compatibilizing agent into PLA matrix improves barrier properties of new materials. The elongation of diffusion tortuosity path occurred with the increase in nanofiller content. The conducted research indicates that the most significant reduction in permeability was observed in the case of systems containing Nanofil2 and poly(ε‐caprolactone). Based on this observation, it can be deduced that the compatibilizing agent improves the dispersion of Nanofil2 in polymer matrix, and beneficially affects the diffusion tortuosity path. POLYM. COMPOS., 36:17–25, 2015. © 2014 Society of Plastics Engineers