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Development of polyurethane poymerization from renewable sources in an experimental unit

Author(s):
Evandro Stoffels Mallmann
Total Authors: 1
Document type: Doctoral Thesis
Institution: Universidade Estadual de Campinas. Faculdade de Engenharia Química
Defense date:
Examining board members:
Rodrigo Alvarenga Rezende; Cristiana Maria Pedroso Yoshida; Classius Ferreira da Silva; Cecilia Amelia de Carvalho Zavaglia
Advisor: Rubens Maciel Filho
Abstract

The malfunctioning or the loss of partial or total function of an organ or a tissue resulting from diseases or traumas is currently one of the most important and serious health problems in the world, reaching a very significant number of people. Thus, it is necessary to build new support devices and materials which contribute to enhance patient health quality. This research project, linked to the Thematic Project "National Institute of Science & Biomanufacturing Technology: Synthesis of Biomaterials, Simulation and Process - Biofabris"(FAPESP Process No. 2008/57860-3), aims the production of polyurethanes (PUs) at both benchtop scale and in an experimental polymerization unit from renewable sources (castor oil) with adequate characteristics as low toxicity, biocompatibility and/or biodegradability in order to be employed as biomaterials. In this study, PUs were synthesized with different proportions of isocyanates (HDB and HDT) and polyol (ricinoleic acid). The physical and chemical characterizations of the samples were carried out with the following techniques: differential scanning calorimetry; thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscope, X-ray microtomography and dynamic mechanical thermal analysis. With the differential scanning calorimetry analysis it was possible to determine the nature of reaction mechanisms and the kinetics involved in PUs synthesis. The results of the infrared spectroscopy showed the bond types in PUs and the thermogravimetric analysis pointed out the decomposition temperature of the materials. Through scanning electron microscopy the PUs structural morphology was verified and the X-ray microtomography determined porosity and average pore size of the samples, indicating that higher isocyanate quantities improve material rigidity. From dynamic mechanical analysis it was possible to define the glass transition temperature. The PUs, in shape of scaffolds, were submitted to in vitro cytotoxicity tests to assess the potential of these biomaterials being applied in the medical field. The direct toxicity evaluation of the produced biomaterials was positive, since only one sample presented cytotoxic behavior towards cells in the MTT assays. Computer simulations were also performed in software ANSYS CFX® where it was possible to investigate the distribution of heat in the synthesis of PUs generated by the incidence of CO2 laser. (AU)

FAPESP's process: 10/07034-0 - Development of Polyurethanes in the Experimental Polymerization from Renewable Sources
Grantee:Evandro Stoffels Mallmann
Support type: Scholarships in Brazil - Doctorate