INVESTIGADORES
ROSALES Caren Soledad
congresos y reuniones científicas
Título:
Modification of PP with CNT as painting agent: influence on performanceof injected pieces
Autor/es:
A. CONSTANINO; C. ROSALES; L. RAMAJO; V. PETTARIN; A. PONTES
Lugar:
Guimarães
Reunión:
Conferencia; International Conference on Polymers and Mould Innovations; 2019
Resumen:
From an industrial point of view, final plastic products should meet both certain structural requirements and adequate aesthetic quality. Manufactured pieces are commonly subjected to different surface finishing tech-niques to achieve desired aesthetic requirements, being the electrostatic painting the most efficient procedure. It offers great economic, environmental and cosmetic advantages, among the great reduction of used paint and volatile emissions as the most relevant. However, this technique cannot be directly applied in polymers due to their insulating properties. Plastic pieces need to be previously prepared by painting them with a primer, adding a further stage to the production cycle. To avoid this extra step, a painting agent could be added to the polymer to modify its electrical properties and make it suitable to be directly electrostatic painted. Carbon nanotubes (CNT) were proposed in this work as an electrostatic painting assistant for polypropylene (PP) in-jected pieces. The present work aims to evaluate how CNTs ? added to increase the panting transfer efficien-cy ? influence the mechanical performance of intricate PP injected moldings. Then a complete characteriza-tion, including morphological, electrical and mechanical characterization ? and their relationship ? of double gated injection molded PP/CNT parts is presented. Differences in CNT orientation were found along the piec-es: while a CNT orientation profile was observed along the thickness of the injected part induced by the mold-ing thermo-mechanical field, CNT were seen randomly distributed in the weld line zone. These dissimilar ori-entations induce a difference of an order of magnitude in the electrical properties of the part that would result in distinct paint transfer efficiency in the same piece. Moreover, mechanical performance of pieces was de-graded by the addition of only 3% of CNT, especially in the weld line zone.