Estudo da influência do índice de fluidez na cinética de critalização de blendas de PP homopolímero com PP copolímero

• Autor(a) principal: Silva, Emanuela Santos
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: http://ri.ufs.br/jspui/handle/riufs/7654
• topic: Engenharia de materiais; Polipropileno; Cristalização; Heterofásico; Cinética; Método de Jeziorny; Polypropylene; Heterophasic; Crystallization; Kinetic; ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

The present work had as objective productions and images of homopolymer PP with heterophasic PP copolymer, seeking to investigate how the fluidity index influenced as the good of the blends. As Blends PPh11 / CP and PPh1.5 / CP were produced by varying the copolymer content (CP) by 25, 50 and 75%. The melt flow indexes of homopolymer PP and PP copolymer were: 11g / 10min (PPh11), 1.5g / 10min (PPh1,5) and 0,8g / 10min (CP). As the legends were prepared in a monorail extruder. The oscillatory dynamic rheological properties were evaluated in an oscillatory shear rheometer. Through the tensile test an evaluation of the mechanical properties was made. A determination of the crystalline phases of the compositions at the exit of the X-ray Diffraction. An analysis of the thermal properties and the study of the non-isothermal crystallization kinetics was performed from Differential Exploratory Calorimetry (DSC). There is no non-isothermal study, as samples were warmed from room temperature to 200 ° C and cooled using 10, 15 and 20 ° C / min cooling rates. A non-isothermal crystallization kinetics for the study of Ozawa, Jeziorny and Kissinger Methods. The results showed that the heterophasic copolymer acted as a nucleant in the more viscous compositions, prepared with PPh1.5. And as crystallization (Ti) and peak crystallization (Tc) temperatures were shifted to higher values. The kinetic parameters, n and kc, behaved in the same manner for all compositions, indicating the growth geometry of the crystal was not affected. Rheological and mechanical characterizations indicate that all systems studied are miscible.