Resina ep?xi aplicada a capacitores : influ?ncia de diferentes agentes de cura

Autor: Silva, Rafael Bitello
Jazyk: portugalština
Rok vydání: 2018
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da PUC_RSPontifícia Universidade Católica do Rio Grande do SulPUC_RS.
Druh dokumentu: masterThesis
Popis: Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-10-11T17:16:47Z No. of bitstreams: 1 Disserta??o Rafael Bitello Silva.pdf: 3894988 bytes, checksum: cf3a5e12050e0f5509ae1930f1b89181 (MD5)
Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-10-17T12:16:39Z (GMT) No. of bitstreams: 1 Disserta??o Rafael Bitello Silva.pdf: 3894988 bytes, checksum: cf3a5e12050e0f5509ae1930f1b89181 (MD5)
Made available in DSpace on 2018-10-17T12:23:40Z (GMT). No. of bitstreams: 1 Disserta??o Rafael Bitello Silva.pdf: 3894988 bytes, checksum: cf3a5e12050e0f5509ae1930f1b89181 (MD5) Previous issue date: 2018-07-16
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
In this study the influence of different commercial curing agents of epoxy resin on film capacitors encapsulation was evaluated. A formulation with DGEBA epoxy resin was used with three different curing agent types: anhydride base, aliphatic amine base and polyamidoamine base. The curing reaction kinetic analysis of each epoxy system was performed by Osawa dynamic method by DSC according ASTM E968. The thermal properties of the epoxy systems were checked by TGA and DSC while the mechanical properties were measured by Shore D hardness and IZOD impact strength, also the a characterization by SEM was performed. The epoxy systems performance in capacitor was verified by qualification tests for film capacitors for automotive application based in AEC-Q200 D, as: exposure to the maximum capacitor operating temperture, exposure to thermal cycles and exposure to humidity. The capacitors were characterized by the capacitance variation while the effects in the epoxy systems were checked by their thermal and mechanical properties change. The systems based on aliphatic amine and polyamidoamine had lower activation energy and higher reaction velocity than the anhydride system. The performance of the capacitor against humidity was similar between the evaluated systems showing low loss of capacitance after the test, whereas against thermal cycles, even the aliphatic amine and polyamidoamine base systems were not affected by reduction of mechanical properties, they had their performance affected by cracks arising. Regarding the performance under exposure to the maximum operating temperature, the anhydride system presented the lowest capacitance loss in the capacitor, followed by the samples with polyamidoamine and aliphatic amine, respectively, which showed a significant reduction of the mechanical properties after prolonged exposure to the temperature of the test.
Neste estudo avaliou-se a influ?ncia de diferentes agentes de cura comerciais de resina ep?xi no encapsulamento de capacitores de filme. Foi utilizado uma formula??o de resina ep?xi DGEBA (diglicidil ?ter de bisfenol-A) com tr?s tipos diferentes de agente de cura: base anidrido, base amina alif?tica e base poliamidoamina. A an?lise da cin?tica da rea??o de cura de cada sistema ep?xi foi realizada pelo m?todo din?mico de Osawa, por DSC conforme ASTM E968. As propriedades t?rmicas dos sistemas ep?xi foram determinadas por TGA e DSC enquanto que as propriedades mec?nicas foram medidas atrav?s de dureza Shore D e resist?ncia ao impacto IZOD, al?m disto foi realizado caracteriza??o por MEV. O desempenho dos sistemas ep?xi no capacitor foi verificado pelos ensaios de qualifica??o de capacitores de filme para aplica??o automotiva baseados na norma AEC-Q200 D, sendo estes: exposi??o a temperatura m?xima do capacitor, exposi??o a ciclos t?rmicos e exposi??o a umidade. Os capacitores foram caracterizados pela varia??o de capacit?ncia enquanto que os efeitos nos sistemas ep?xi foram acompanhados pela altera??o em suas propriedades t?rmicas e mec?nicas. Os sistemas a base de amina alif?tica e poliamidoamina apresentaram menor energia de ativa??o e maior velocidade de rea??o que o sistema anidrido. O desempenho do capacitor frente a umidade foi similar entre os sistemas avaliados com baixa perda de capacit?ncia ap?s o ensaio, enquanto que frente aos ciclos t?rmicos, mesmo n?o apresentando redu??o de propriedades mec?nicas os sistemas base amina alif?tica e poliamidoamina tiveram seu desempenho afetado pelo aparecimento de trincas. Em rela??o ao desempenho sob exposi??o ? temperatura m?xima o sistema anidrido foi o que apresentou menor perda de capacit?ncia no capacitor, seguido das amostras com poliamidoamina e amina alif?tica, respectivamente, sendo que estas apresentaram redu??o significativa das propriedades mec?nicas ap?s exposi??o prolongada a temperatura do ensaio.
Databáze: Networked Digital Library of Theses & Dissertations
Externí odkaz: