Tung Oil Based-Polyurethanes Reinforced with Wood Flour

U. CASADO; N. E. MARCOVICH; M. I. ARANGUEN; M. A. MOSIEWICKI

Rio de Janeiro, Brasil

Conferencia; Internacional Conference on Science and Technology of Composite Materials, COMAT2007; 2007

A liquid polymer precursor was synthesized from tung oil, and used in the preparation of polyurethanes (PU) and their wood flour (WF) composites. The synthesis of the precursor was carried out by hydroxylation of the unsaturations of the triglycerides that form the vegetable oil, followed by alcoholysis with triethanolamine. In this way, the original tung oil was converted into a highly hydroxylated branched polyol. The tung oil derived polyol resulted in a high viscosity liquid, thus to obtain a crosslinked polyurethanes, the polyol was reacted with a polymeric isocyanate (p-MDI) in tetrahydrofurane (THF) solution. To prepare wood flour –PU composites, the reinforcement was first mixed with the polyol in THF solution and then, reacted with the isocyanate component. A ratio NCO to OH = 1.1 was used in all the formulations. SEM micrographs of the interfacial region showed good adhesion between reinforcement and matrix. Taking into account that polymer and WF are polar materials, a strong interaction of the components affecting their structures and properties may be expected The addition of the rigid fillers increased both, tensile and storage modulus of the composite and, as anticipated, the increase was more important at temperatures above the glass-rubber transitions. The glass-rubber transition region for the neat polyurethane was very broad due to the large molar mass distribution of vegetable oil based polymers, which leads to a large amount of relaxation modes. curves became broader and shifted toward higher temperatures for theäThe tan composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. synthesized from tung oil, and used in the preparation of polyurethanes (PU) and their wood flour (WF) composites. The synthesis of the precursor was carried out by hydroxylation of the unsaturations of the triglycerides that form the vegetable oil, followed by alcoholysis with triethanolamine. In this way, the original tung oil was converted into a highly hydroxylated branched polyol. The tung oil derived polyol resulted in a high viscosity liquid, thus to obtain a crosslinked polyurethanes, the polyol was reacted with a polymeric isocyanate (p-MDI) in tetrahydrofurane (THF) solution. To prepare wood flour –PU composites, the reinforcement was first mixed with the polyol in THF solution and then, reacted with the isocyanate component. A ratio NCO to OH = 1.1 was used in all the formulations. SEM micrographs of the interfacial region showed good adhesion between reinforcement and matrix. Taking into account that polymer and WF are polar materials, a strong interaction of the components affecting their structures and properties may be expected The addition of the rigid fillers increased both, tensile and storage modulus of the composite and, as anticipated, the increase was more important at temperatures above the glass-rubber transitions. The glass-rubber transition region for the neat polyurethane was very broad due to the large molar mass distribution of vegetable oil based polymers, which leads to a large amount of relaxation modes. curves became broader and shifted toward higher temperatures for theäThe tan composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. A liquid polymer precursor was synthesized from tung oil, and used in the preparation of polyurethanes (PU) and their wood flour (WF) composites. The synthesis of the precursor was carried out by hydroxylation of the unsaturations of the triglycerides that form the vegetable oil, followed by alcoholysis with triethanolamine. In this way, the original tung oil was converted into a highly hydroxylated branched polyol. The tung oil derived polyol resulted in a high viscosity liquid, thus to obtain a crosslinked polyurethanes, the polyol was reacted with a polymeric isocyanate (p-MDI) in tetrahydrofurane (THF) solution. To prepare wood flour –PU composites, the reinforcement was first mixed with the polyol in THF solution and then, reacted with the isocyanate component. A ratio NCO to OH = 1.1 was used in all the formulations. SEM micrographs of the interfacial region showed good adhesion between reinforcement and matrix. Taking into account that polymer and WF are polar materials, a strong interaction of the components affecting their structures and properties may be expected The addition of the rigid fillers increased both, tensile and storage modulus of the composite and, as anticipated, the increase was more important at temperatures above the glass-rubber transitions. The glass-rubber transition region for the neat polyurethane was very broad due to the large molar mass distribution of vegetable oil based polymers, which leads to a large amount of relaxation modes. curves became broader and shifted toward higher temperatures for theäThe tan composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied. äThe tan composites, suggesting a strong interaction between the reinforcement and the PU matrix. WF has free hydroxyl groups able to interact chemically with the pMDI and to originate new bonds which gave higher thermal stability to reinforced polyurethanes. The microbiological degradation of PU matrix and composites is being studied.