Made available in DSpace on 2014-12-17T15:01:46Z (GMT). No. of bitstreams: 1
JuceliaMER.pdf: 2171315 bytes, checksum: 6d1b358ee82a3e95a8b3fb30782bdf76 (MD5)
Previous issue date: 2005-12-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Polyurethanes are very versatile macromolecular materials that can be used in the form of powders, adhesives and elastomers. As a consequence, they constitute important subject for research as well as outstanding materials used in several manufacturing processes. In addition to the search for new polyurethanes, the kinetics control during its preparation is a very important topic, mainly if the polyurethane is obtained via bulk polymerization. The work in thesis was directed towards this subject, particularly the synthesis of polyurethanes based castor oil and isophorone diisocianate. As a first step castor oil characterized using the following analytical methods: iodine index, saponification index, refraction index, humidity content and infrared absorption spectroscopy (FTIR). As a second step, test specimens of these polyurethanes were obtained via bulk polymerization and were submitted to swelling experiments with different solvents. From these experiments, the Hildebrand parameter was determined for this material. Finally, bulk polymerization was carried out in a differential scanning calorimetry (DSC) equipment, using different heating rates, at two conditions: without catalyst and with dibutyltin dilaurate (DBTDL) as catalyst. The DSC curves were adjusted to a kinetic model, using the isoconversional method, indicating the autocatalytic effect characteristic of this class of polymerization reaction / Poliuretanas s?o pol?meros de grande versatilidade, podendo ser usadas na forma de p?s, adesivos ou elast?meros. Por este motivo, as poliuretanas s?o amplamente pesquisadas e utilizadas nas ind?strias. Paralelamente ? busca por novas poliuretanas, ? importante o controle cin?tico durante sua obten??o, principalmente se estas s?o obtidas via polimeriza??o em massa. O trabalho desta tese aborda este problema, especificamente no caso da obten??o de poliuretanas derivadas do ?leo de mamona e diisocianato de isoforona. Para isto, primeiramente o ?leo de mamona foi caracterizado atrav?s dos seguintes m?todos anal?ticos: ?ndice de iodo, ?ndice de saponifica??o, ?ndice de refra??o, ?ndice de hidroxila, teor de umidade e espectroscopia de absor??o na regi?o do infravermelho (FTIR). Como segundo passo, os corpos de prova dessas poliuretanas foram obtidos atrav?s de polimeriza??o em massa e submetidos a ensaios de inchamento com diferentes solventes. A partir destes ensaios o par?metro de Hildebrand foi determinado para este material. Finalmente, a polimeriza??o em massa desse material foi executada em equipamento de calorimetria explorat?ria diferencial (DSC) a diferentes taxas de aquecimento sob duas condi??es: sem catalisador e com o catalisador, dibutil-dilaurato de estanho (DBTDL). As curvas de DSC foram ajustadas a modelos cin?ticos, usando o m?todo isoconversional, caracterizando o car?ter autocatal?tico da forma??o de poliuretanas
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15883 |
| Date | 15 December 2005 |
| Creators | Rodrigues, Juc?lia Maria Emerenciano |
| Contributors | CPF:07286937391, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=null, Barbosa Sobrinho, Ariosvaldo Alves, CPF:23702338420, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4703687T7, Pereira, M?rcia Rodrigues, CPF:83115951787, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788568T8, Fonseca, Jos? Luis Cardozo, Dantas, Tereza Neuma de Castro |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Qu?mica, UFRN, BR, Pesquisa e Desenvolvimento de Tecnologias Regionais |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0025 seconds