Thermo-oxidative degradation kinetics of renewable hybrid polyurethane–urea obtained from air-oxidized soybean oil
- 92 Downloads
This study explores the synthesis and kinetics of non-isothermal thermo-oxidative degradation of renewable hybrid polyurethane (PU)–urea obtained from air-oxidized soybean oil. Fourier transformed infrared spectroscopy (FTIR) and thermogravimetry (TG) analyses were performed, aiming to verify chemical changes and the kinetics parameters using different approaches for the samples obtained. FTIR confirmed that a polymerization process occurred as well and modification in the relative hydrogen bonds is due to the formed urea groups that formed in the hybrid materials. TG analysis showed a dependence of the activation energy (using the FWO and KAS model-free methods) on the degree of conversion for all samples studied in three different degradation steps. The most probable degradation mechanism was tested by using a multivariate nonlinear regression by using the F statistical test. For all samples, the autocatalytic model successfully described the thermo-oxidative degradation, which is in accordance with the chemical degradation process for polyurethanes. Finally, thermal degradation in the time function was estimated and more satisfactory results were obtained by comparing the literature data for similar systems. So, it was possible to obtain reliable and consistent results of the kinetic parameters, which are essential for academic and industrial purposes.
KeywordsRenewable hybrid materials Kinetics Thermo-oxidative Polyurethane–urea
The authors thank the “Mantova Industria de tubos flexíveis” for donating MDI and FAPERGS for a scholarship to Pedro A. Ourique. This work was supported by CNPq—National Council for Scientific and Technological Development, Brazil (Grant 473402/2013-0 and 308241/2015-0).
- 1.Ionescu M. Chemistry and technology of polyols for polyurethanes. Shrewsbury: iSmithers Rapra Publishing; 2005.Google Scholar
- 2.Oertel G, Abele L. Polyurethane handbook: chemistry, raw materials, processing, application, properties. Macmillan: Hanser Publishers. Distributed in USA by Scientific and Technical Books; 1985.Google Scholar
- 12.Ourique PA, Gril JML, Guillaume GW, Wanke CH, Echeverrigaray SG, Bianchi O. Synthesis and characterization of the polyols by air oxidation of soybean oil and its effect on the morphology and dynamic mechanical properties of poly(vinyl chloride) blends. J Appl Polym Sci. 2015. https://doi.org/10.1002/app.42102.Google Scholar
- 14.Hou CT. Microbial oxidation of unsaturated fatty acids. In: Saul LN, Allen IL, editors. Advances in applied microbiology. Cambridge: Academic Press; 1995. p. 1–23.Google Scholar
- 27.Brinker CJ, Scherer GW. Sol–gel science: the physics and chemistry of sol–gel processing. Amsterdam: Elsevier; 2013.Google Scholar
- 39.Akahira T, Sunose T. Method of determining activation deterioration constant of electrical insulating materials. Res Rep Chiba Inst Technol (Sci Technol). 1971;16:22–31.Google Scholar
- 44.Setyaningrum DL, Riyanto S, Rohman A. Analysis of corn and soybean oils in red fruit oil using FTIR spectroscopy in combination with partial least square. Int Food Res J. 2013;20:1977–81.Google Scholar
- 48.Luna-López JA, Carrillo-López J, Aceves-Mijares M, Morales-Sánchez A, Falcony C. FTIR and photoluminescence of annealed silicon rich oxide films. Superficies y vacío. 2009;22:11–4.Google Scholar