Insights into Compatibilization of Poly(ε-caprolactone)-based Biocomposites with Diisocyanates as Modifiers of Cellulose Fillers
This study aimed to analyze the impact of cellulose fillers’ modification with diisocyanates on the performance of composites based on the poly(ε-caprolactone) (PCL) matrix. Four most commonly used diisocyantes (isophorone, hexamethylene, toluene, and methylene diphenyl) were applied as modifiers of cellulose fillers (5 and 15 wt% per mass of filler). Modified fillers were introduced in the amount of 30 wt% into the PCL matrix. Chemical structure, thermal, static and dynamic mechanical properties of composites were investigated using Fourier transform infrared spectroscopy, differential scanning calorimetry, tensile, hardness and rebound resilience tests, and dynamic mechanical analysis, respectively. Modifications of cellulosic fillers resulted in the decrease of matrix crystallinity and enhancement of interfacial interactions, causing even a two-fold increase of tensile strength and a 25% rise of modulus. These results indicate that through proper adjustment of type and content of diisocyanate modifier, composites’ properties may be engineered.