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Previous issue date: 2017-10-16 / As t?cnicas de auto-reparo em resinas ep?xi v?m sendo desenvolvidas buscando aumentar a vida ?til e reduzir os custos associados ? manuten??o desses materiais durante o servi?o. A adi??o de termopl?sticos ? matriz termofixa produzindo resinas repar?veis aparece como t?cnica de reparo promissora. Neste trabalho, o termopl?stico poli (etileno-co-?cido-metacr?lico) (EMAA) foi adicionado no plano m?dio de laminados comp?sitos carbono-ep?xi para fabrica??o de um sistema de reparo. Foram fabricadas placas com 5%, 10% e 15% de EMAA em massa de resina do prepreg. Ensaios de resist?ncia ao cisalhamento interlaminar (ILSS), an?lise din?mico mec?nica (DMA), espectroscopia de infravermelho por transformada de Fourier (FTIR), microscopia eletr?nica de varredura (MEV) e microscopia eletr?nica de varredura com fonte de emiss?o de campo (MEV-FEG) foram conduzidos para avaliar o efeito da adi??o desse termopl?stico ao comp?sito e seu comportamento antes e ap?s o reparo. As amostras reparadas n?o apresentaram aumento na resist?ncia ao cisalhamento interlaminar (ILSS) ap?s o reparo. Entretanto, para maiores porcentagens de EMAA, houve redu??o dessa propriedade, al?m de redu??o de m?dulo de elasticidade e da temperatura de transi??o v?trea (Tg), em rela??o aos valores apresentados pelo comp?sito puro. Imagens de MEV confirmaram a forte ades?o entre o EMAA e a resina ep?xi, formando uma camada adesiva que impediu a forma??o de delamina??es no plano m?dio do laminado. / Self-healing techniques in epoxy resins have been developed to improve the durability and reduce costs associated with repairs of these materials during service. The addition of thermoplastics into the thermoset matrix producing mendable resins appears as a promising self-healing technique. In this study, poly(ethylene-co-methacrylic acid) (EMAA) was added in the mid-plane of carbon fiber-epoxy composites laminates to produce a self-healing system. Plates were manufactured with addition of 5%, 10% and 15% of EMAA as related to the resin weight of prepreg. Interlaminar shear strength test (ILSS), dynamic mechanical analysis (DMA), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and field-emission gun scanning electron microcopy (FEG-SEM) were employed in order to evaluate the effect of the addition of the thermoplastic to the composite and its behavior before and after a healing cycle. The healed samples did not show an increase in interlaminar shear strength (ILSS) after healing. However, for higher percentages of EMAA there was a reduction of this property, besides a reduction of Young?s modulus and glass transition temperature (Tg), in relation to the values presented by the unmodified composite. SEM images confirmed the strong adhesion between EMAA and epoxy resin, which produced an adhesive layer that prevented delamination in the mid-plane of the laminate.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/24726 |
| Date | 16 October 2017 |
| Creators | Nascimento, Allana Azevedo do |
| Contributors | 04561659676, Ferreira, Evans Paiva da Costa, 72074094434, Cioffi, Maria Odila Hil?rio, 09840732803, Melo, Jos? Daniel Diniz, Barbosa, Ana Paula Cysne |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, UFRN, Brasil |
| 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 UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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