title: Polyurethane nanocomposites incorporating biobased polyols and reinforced with a low fraction of cellulose nanocrystals.
abstract: High solids content polyurethane (PU) nanocomposites with enhanced thermal and mechanical properties were produced by incorporating of low fractions of cellulose nanocrystals (CNC) in a solvent-free process. This involved the use of a simple procedure to produce well dispersed and stable suspensions of CNC in biobased polyols, which were then used to produce PU-CNC nanocomposites. Transmission electron microscopy revealed that individual CNC particles were dispersed homogenously within the PU matrix. FTIR results suggested that CNC particles are covalently bonded to the PU molecular chains during polymerization. The thermal mechanical properties of the nanocomposites are significantly improved over pure PU as indicated by differential scanning calorimetry and dynamic mechanical analysis. Compared to pure PU, the PU nanocomposites made with the addition of only 0.5% of CNC had glass transition temperatures that were 6°C higher, their Young's moduli were about 10% higher and their abrasion resistance was higher by about 25%. The optimal composition contains only 0.5% CNC (w/w) which indicates that there is good potential for utilization of low levels of CNC for reinforcement of PU composites made using biobased polyols.
authors: Lipid Chemistry Group, Department of Agricultural Food and Nutritional Science, 4-10 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada. Electronic address: xkong@ualberta.ca.
authors: Xiaohua
authors: X
authors: Kong
authors: Processing Technologies, Alberta Innovates-Technology Futures, 250 Karl Clark Road, Edmonton, Alberta, T6N 1E4, Canada.
authors: Liyan
authors: L
authors: Zhao
authors: Lipid Chemistry Group, Department of Agricultural Food and Nutritional Science, 4-10 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada.
authors: Jonathan M
authors: JM
authors: Curtis
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*
chemical_list: D011108:Polymers; D011140:Polyurethanes; C024617:polyol; D002482:Cellulose
keywords: Abrasion resistance; Biobased polyurethane; Cellulose nanocrystals; Cross-linking density; Nanocomposites; Thermal stability