Waterborne polyurethane nanocomposites based on vegetable oil and microfibrillated cellulose

Abstract

This work analyzes the differences in the final properties of two waterborne polyurethanes (WBPU) prepared with twomacrodiols of different chemical structure, but similar molecular weight, as well as the variations caused by incorporating low percentagesof microfibrillated cellulose nanocrystals. One of the polyurethanes was based on a synthetic but biodegradable precursor (polycaprolactonediol, PCL) and a second one based on a bio-based macrodiol derived from castor oil (CO1). The bio-based materialpresented higher mechanical properties at room temperature than the synthetic one, with the Young?s modulus (MPa) ranging from2.2360.09 to 84.8860.96 for the PCL and bio-based WBPUs, respectively. Additionally, the PCL-based WBPU showed to be moresensitive to the incorporation of cellulose than the bio-based WBPU, and it also suffered changes during time due to delayed crystallization.The behavior of the two systems were compared and related to the different structure of the macrodiols that led to differentinterfacial interactions.