Impact of Natural Oil-Based Recycled Polyols on Properties of Cast Polyurethanes

Hynek Beneš, Aleksandra Paruzel, Jiří Hodan and Olga Trhlíková
2018 Journal of Renewable Materials  
In this study, castor oil, rapeseed oil and medium chain triglycerides of coconut oil, were transesterified by means of 2-ethyl-2-hydroxymethyl-1,3-propanediol (trimethylolpropane) and consequently used to convert polycarbonate waste from end-of-life vehicles into liquid polyols. The prepared recycled polyols, composed uniquely of renewable and recycled components, had a hydroxyl number of ca. 250 mg KOH• g −1 . They were successfully applied as 100% replacement of a virgin polyol for
more » ... n of solid crosslinked polyurethanes (PU) by solvent-free casting. The produced rigid cast PU exhibited the main transition temperature ranging from 44°C to 53°C, the hardness value from 46 to 61 Shore D and the beneficial low water absorption (0.4-0.5 wt.%). The PU network structure was highly influenced by the presence of aromatic structures of polycarbonate-units and fatty acid compositions. A suitable selection of natural oil thus enabled to adjust thermo-mechanical properties and promote excellent optical transparency of the produced PU. KEYWORDS: Natural oil, cast polyurethane, bio-based, polycarbonate waste, recycling EXPERIMENTAL Synthesis of Transesterified Oils Castor oil (CO, puriss, Sigma-Aldrich), rapeseed oil (RO, Glencore Agriculture Czech Ltd, Czech Republic), and medium chain triglycerides of coconut oil (CCO, Environ Ltd., Czech Republic)-the byproduct from soap industry, were used as received and analyzed (Table 1 ).
doi:10.32604/jrm.2018.00011 fatcat:jbl7ylpzu5brxg23z5mabo5xtu