Made available in DSpace on 2014-12-17T14:07:11Z (GMT). No. of bitstreams: 1 QueremAFA_DISSERT.pdf: 6927049 bytes, checksum: 5fbf755901320194b71aa9dc0dc0b657 (MD5) Previous issue date: 2013-06-07 / Studies indicate that a variation in the degree of crystallinity of the components of a polymer blend influences the mechanical properties. This variation can be obtained by subjecting the blend to heat treatments that lead to changes in the spherulitic structure. The aim of this work is to analyze the influence of different heat treatments on the variation of the degree of crystallinity and to establish a relationship between this variation and the mechanical behavior of poly(methyl methacrylate)/poly(ethylene terephthalate) recycled (PMMA / PETrec) with and without the use of compatibilizer agent poly(methyl methacrylate-al-glycidyl methacrylate-al-ethyl acrylate) (MMAGMA- EA). All compositions were subjected to two heat treatments. T1 heat treatment the samples were treated at 130 ? C for 30 minutes and cooled in air. In T2, the samples were treated at 230 ? C for 5 minutes and cooled to approximately -10 ? C. The variation of the degree of crystallinity was determined by the proportional relationship between crystallinity and density, with the density measured by pycnometry. The mechanical behavior was verified by tensile tests with and without the presence of notches and pre-cracks, and by method of fracture toughness in plane strain (KIC). We used the scanning electron microscopy (SEM) to analyze the fracture surface of the samples. The compositions subjected to heat treatment T1, in general, showed an increase in the degree of crystallinity in tensile strength and a tendency to decrease in toughness, while compositions undergoing treatment T2 showed that the opposite behavior. Therefore, this work showed that heat treatment can give a polymer blend further diversity of its properties, this being caused by changes in the crystal structure / Estudos apontam que uma varia??o no grau de cristalinidade dos componentes de uma blenda polim?rica influencia nas suas propriedades mec?nicas. Essa varia??o pode ser obtida pela submiss?o da blenda a tratamentos t?rmicos que levam a modifica??es da estrutura esferul?tica. O objetivo desse trabalho ? analisar a influ?ncia de diferentes tratamentos t?rmicos na varia??o do grau de cristalinidade e estabelecer uma rela??o entre essa varia??o e o comportamento mec?nico da blenda poli(metacrilato de metila)/poli(tereftalato de etileno) reciclado (PMMA/PETrec) com e sem o uso do agente compatibilizante interfacial poli(metacrilato de metila-almetacrilato de glicidila-al-acrilato de etila) (MMA-GMA-EA). Todas as composi??es foram submetidas a dois tratamentos t?rmicos. No tratamento t?rmico T1 as amostras foram tratadas a 130 ?C por 30 minutos e resfriadas ao ar. No tratamento T2 as amostras foram tratadas a 230 ?C por 5 minutos e resfriadas a aproximadamente 10 ?C. A varia??o do grau de cristalinidade foi verificada pela rela??o de proporcionalidade existente entre cristalinidade e densidade, sendo a densidade medida por picnometria. O comportamento mec?nico foi verificado por ensaios de tra??o, com e sem a presen?a de entalhes e pr?-trincas, e pelo m?todo da tenacidade ? fratura em estado plano de deforma??o (KIC). Utilizou-se a microscopia eletr?nica de varredura (MEV) para analisar a superf?cie de fratura das amostras. As composi??es submetidas ao tratamento t?rmico T1, de uma forma geral, mostraram aumento no grau de cristalinidade, na resist?ncia ? tra??o e uma tend?ncia ? redu??o na tenacidade ? fratura, enquanto que as composi??es submetidas ao tratamento T2 mostraram um comportamento oposto a esse. Portanto, este trabalho mostrou que um tratamento t?rmico pode conferir a uma blenda polim?rica uma diversidade ainda maior de suas propriedades, sendo essa ocasionada pelas mudan?as na estrutura cristalina

Graduation thesis is specialized on dilemma of the integrated circuits with ball grid array. Chapter two describes several types of packages and confrontation of their characteristics. Chapter three considers possibilities of corrections these boards bedded with packages, mounting and demounting of these packages, method of camera control and also inspection of the soldering process. Chapter four attend to practical measuring of thermal profiles and their optimalization.