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Previous issue date: 2016 / Novos poli?steres a partir do ?cido isoft?lico e glicerol foram sintetizados por policondensa??o. As amostras foram sintetizadas em diferentes condi??es obtidas pela combina??o das vari?veis: propor??o molar ?cido isoft?lico:glicerol, temperatura, press?o e tempo de rea??o, denominadas AM1 (1,0:2,3; 195 ?C; 1,0 atm; 100 min), AM10 (1,0:1,5, 210 ?C; 0,29 atm; 30 min), AM11 (1:1,5, 203 ?C, 1,0 atm; 60 min), AM12 (1:1,5, 197 ?C; 1,0 atm; 110 min) e AM13 (1,0:2,3, aquecimento por micro-ondas; 1,0 atm; 3 mim). As amostras obtidas foram caracterizadas por espectroscopia na regi?o de infravermelho (FTIR), an?lise termogravim?trica (TGA) e
calorimetria diferencial explorat?ria (DSC) e difratometria de raios-x (DRX). Filmes dos poli?steres foram analisados por microscopia eletr?nica de varredura (MEV) e ?ngulo de contato. A partir dos espectros de FTIR foi poss?vel confirmar a esterifica??o para todos os materiais sintetizados pelo aparecimento da banda em ~1710 cm-1 , caracter?stica da liga??o C=O de ?ster. A an?lise das curvas de TGA e suas derivadas (DTG) demonstrou para o poli?ster AM1 duas etapas de degrada??o t?rmica predominantes: em 214 ?C e 393 ?C. O poli?ster AM10 apresentou dois principais picos de degrada??o t?rmica localizadas em 247 ?C e 373 ?C. Os
poli?steres AM11, AM12 e AM13 apresentaram picos de degrada??o bem pr?ximas entre si, em 415 ?C, 423 ?C e 413 ?C, respectivamente. A partir dos termogramas de DSC constatou-se a temperatura de transi??o v?trea de cada poli?ster em 47,31 ?C, 48,06 ?C, 39,62 ?C, 17,44 ?C, 56,44 ?C, para AM1, AM10, AM11, AM12 e AM13, respectivamente. Os picos das temperaturas de fus?o foram identificadas para a AM1 em 131,9 ?C, AM10 em 131,2 ?C, 148.0 ?C e 164,5 ?C, para a AM11 em 144,5 ?C e 160,7 ?C, para AM12 em 149,6 ?C, 163,5 ?C, 169,7 ?C e para a AM13 em 131,9 ?C e 149,2 ?C. Os difratogramas demonstraram que os materiais
sintetizados s?o semicristalinos. A micrografias de MEV revelaram uma morfologia homog?nia para as amostras AM12 e AM13, e heterog?nea com dom?nios escuros AM10 e AM11. Os valores da energia livre superficial foram 66, 59, 61 e 67 mN.m-1 para as amostras AM10, AM11, AM12 e AM13, respectivamente. Testes de for?a necess?ria para romper a ader?ncia foram realizados nos diferentes tipos de amostras que se comportaram de forma vari?vel nos cinco diferentes substratos utilizados. No substrato de vidro, a?o e cobre o poli?ster AM10 apresentou maior resist?ncia para a separa??o das placas com o valor de 4,18, 5,88 e 8,19
Kgf/mm?, respectivamente. No alum?nio a AM11 apresentou valor de 2,02 Kgf mm?. E, na madeira o poli?ster AM12 demonstrou press?o necess?ria para o rompimento de 4,40 Kgf/mm?. Esses resultados demonstram a possibilidade de aplica??o dos poliesteres sintetizados neste trabalho como adesivos hot melt. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Tecnologia, Sa?de e Sociedade, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / New polyester from isophthalic acid and glycerol were synthesized by polycondensation. The samples were synthesized at different conditions obtained by the combination of variable, namely isophthalic acid: glycerol molar ratio, temperature, pressure and reaction time. These different experimental conditions yielded samples called AM1 (1.0:2.3, 195 ?C; 1.0 atm; 100 min), AM10 (1.0:1.5, 210 ?C; 0.29 atm, 30 min), AM11 (1:1.5, 203 ?C, 1.0 atm, 60 min), AM12 (1:1.5; 197 ?C; 1.0 atm; 110 min) and AM13 (1.0:2.3, microwave heating; 1.0 atm, 3 min). Samples were characterized by infrared spectroscopy (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), X-ray diffractometry (XRD). Films of polyesters were analyzed by scanning electron microscopy (SEM) and contact angle. FTIR spectra confirmed that the esterification occurred for all materials synthesized by the appearance of the band at ~ 1710 cm-1, characteristic of the C=O stretching. TGA curve and its derivatives (DTG) demonstrated two main thermal degradation peaks at 214 ?C and 393 ?C for AM1 sample. The AM10 polyester presented two main thermal degradations peaks located at 247 ?C and 373 ?C. The thermal degradation peaks of AM11, AM12 and AM13 were very close and occurred at 415 ?C, 423 ?C, and 413 ?C, respectively. From the DSC thermograms, it was
found glass transition temperature of each polyester at 47.31 ?C, 48.06 ?C, 39.62 ?C, 17.44 ?C, 56.44 ?C, for AM1, AM10, AM11, AM12 and AM13, respectively. Melting temperature was founded for AM1 at 131.9 ?C, for AM10 at 131.2 ?C, 148.0 ?C and 164.5 ?C, for AM11 at 144.5 and 160.7 ?C, for AM12 at 149.6 ?C, 163.5 ?C and 169.7 ? C, and for AM13 at 131.9 ? C and 149.2 ?C. The XRD difratograms reveled that syntethized materials are semi-crystalline. MEV analisys revealed the existence of dark domains for AM10 and AM11 samples, and a homogeneous smooth surface for AM12 and AM13 samples. Surface free energy values were
of 66, 59, 61 and 67 mN.m-1 for AM10, AM11, AM12 and AM13, respectively. Single lap shear tests were carried out in five different types of substrates. For glass, steel and copper AM10 showed greater resistance, with shear strengh value of 4.18 Kgf mm? 5.88 Kgf mm? and 8.19 kgf mm?, respectively. For aluminum, AM11 showed a shear strengh value of 2.02 kgf mm?. And, for wood, AM12 showed shear strengh value of 4.40 kgf mm?. These results revealed technological applicability for polyesteres synthetized here, such as their use as hot melt adhesives.
| Identifer | oai:union.ndltd.org:IBICT/oai:acervo.ufvjm.edu.br/jspui:1/1670 |
| Date | 07 March 2016 |
| Creators | Vieira, Gledsa Alves |
| Contributors | Monteiro, Douglas Santos, Meireles, Carla da Silva, Barros, Aruana Rocha, Costa, Val?ria Cristina da, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Monteiro, Douglas Santos |
| Publisher | UFVJM |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFVJM, instname:Universidade Federal dos Vales do Jequitinhonha e Mucuri, instacron:UFVJM |
| Rights | A concess?o da licen?a deste item refere-se ao ? termo de autoriza??o impresso assinado pelo autor, assim como na licen?a Creative Commons, com as seguintes condi??es: Na qualidade de titular dos direitos de autor da publica??o, autorizo a Universidade Federal dos Vales do Jequitinhonha e Mucuri e o IBICT a disponibilizar por meio de seus reposit?rios, sem ressarcimento dos direitos autorais, de acordo com a Lei n? 9610/98, o texto integral da obra disponibilizada, conforme permiss?es assinaladas, para fins de leitura, impress?o e/ou download, a t?tulo de divulga??o da produ??o cient?fica brasileira, e preserva??o, a partir desta data., info:eu-repo/semantics/openAccess |
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