Influence Of Processing Induced Morphology On The Performance Of PP Injected Intricate Pieces Modified With MWCNT As A Painting Aide

COSTANTINO, ALEJANDRA; LEANDRO RAMAJO; JULIO VIANA; CAREN ROSALES; ANTONIO PONTES; VALERIA PETTARIN

Advanced Materials Letters

IAAM-VBRI Press

Año: 2021 vol. 12 p. 21041618 - 21041618

0976-3961

Carbon nanotubes are currently added to polymers to avoid extra-stages in theelectrostatic painting process. However, the attained particle network after processing afinal part could affect the mechanical properties and thermal stability of nanocomposites.It is then important to evaluate not only the functional properties, but also the overallperformance of these pieces. In this work, boxes of polypropylene (PP) modified with multiwalledcarbon nanotubes (MWCNT) were injection molded. Morphology induced byprocessing was characterized at different locations of the moldings to correlate theinfluence of in-homogeneities and flow pattern with the overall performance of the moldedboxes. PP/MWCNT presented a better aesthetic quality and a markedly better thermalstability than pure PP. It was confirmed that the nanocomposite has high dielectricpermittivity, low dielectric losses and relatively good DC conductivity. Regardingmechanical properties, MWCNT induced a slight improvement in flexural elastic modulus.Although fracture initiated at practically the same loading levels for both materials, thepropagation energy was deteriorated by MWCNT presence. Differences in both electricaland mechanical behavior were found trough out the PP/MWCNT pieces as result of distinctMWCNT orientation and distribution. It was then concluded that processing has a greatinfluence on parts performance.