CARACTERIZAÇÃO REOLÓGICA E TÉRMICA DE BLENDAS POLIMÉRICAS DE PEBD/ m-PELBD PROCESSADAS EM EXTRUSORAS MONO E DUPLA ROSCA

• Autor(a) principal: Patel, Volnei
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UEPG
• Texto Completo: http://tede2.uepg.br/jspui/handle/prefix/1445
• topic: blendas poliméricas; PEBD, m-PELBD; análises térmicas; análises reológicas; polymer blends; PEBD; m-PELBD; thermal analysis; rheological analyzes; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

In this work, blends of PEBD/m-PELBD with typical applications in the area of packaging films were studied. Thermal and rheological properties of blends of PEBD/m-PELBD were analyzed in the proportions of 80/20; 75/25; 70/30; 65/35;60/40, as well as the pure polymers. The samples were processed in single and twin screw extruders, thus allowing the evaluation of the influence of homogenization on the thermal and rheological properties. The effect of variations of the compositions of the blends on thermal properties was analyzed using the Differential Scanning Calorimetry technique (DSC), and the effect of variation in the rheology of the blends was analyzed in parallel plate and capillary rheometer for the various compositions and at different temperatures. The results obtained from the thermal analysis showed no variations in the melting and crystallization temperatures with variation of the composition, and the pure m-PELBD presented a melting temperature of 108ºC and PEBD 105ºC. The rheological analysis showed the high influence of PEBD in viscosity at low shear rates, presenting high viscosity. However, as of 100 1/s the reversal of the viscosity curves is observed,where m-PELBD has more influence. By means of rheological analysis, the phase behavior of the blends was investigated, which proved insoluble in all compositions in the molten state. However, due to the close proximity of the values of the melting temperature of the pure components, it was not possible to identify the expected second melting peak in the thermal analysis. Comparing the thermal and rheological results of the processed blends in the extruders of single and twin screws, no significant variations were observed. The thermal and rheological results obtained in this study show that possible small variations in composition during the feed dispensing process in the extruder would not generate significant instabilities in the process.