Biobased Composites Obtained by Using Organic Solvents

1 Biobased Composites Obtained by Using Organic Solvents 

Wik et al. [26] reported the reaction of a natural polyol derived from castor oil and polymeric 4,4 -diphenylmethane diisocyanate (pMDl) used to prepare solid materials reinforced with nanocellulose. The polyol was obtained by the reaction of castor oil with triethanolamine. The reaction between the castor oil-based polyol and the isocyanate started almost immediately after mixing these main components, even without the addition of a catalyst. This fact forced the use of an organic solvent to reduce the initial reaction rate, which was evaporated during the curing process. Nanocellulose obtained by acid hydrolysis of commercial microcrystalline cellulose was added to the polyol (0.5, 1, and 3 wt%) and dispersed by sonication. It was found that the addition 

Sample Tensile Modulus, (MPa) Stress at break,o (MPa) Deformation at break. 

Floras et al. [63] dispersed nanocellulose in different concentrations (0.1, 0.5, 1.0, 1.5, 2.0 and 2.5% by weight) into a completely biobased thermoplastic polyurethane (TPU) derived entirely from oleic acid, using l,18-octadec-9-endiol (ODEDO), 1,7-heptamethylene diisocyanate (HPMDI), and 1,9-nonanediol (NDO), each synthesized entirely from vegetable oil [64-66]. In this case, the cellulose was extracted from 

Regarding mechanical properties, the nanocomposites demonstrated enhanced stress and elongation at break compared to the neat TPU. The best results were obtained with 0.5 wt% of NC in the TPU the elongation at break of this sample was improved from 178% to 269%, and its stress at break increased from 29.3 to 40.5 MPa. Moreover, in all of the reinforced samples, the glass transition temperature, melting temperature. 

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