Tuning of microstructure in engineered poly (trimethylene terephthalate) based blends with nano inclusion as multifunctional additive

Abstract

Immiscible blends and their composites are heterogeneous and have variable morphology due to variation in mesophase regions. Tuning, i.e. controlling the phase dimension is important, thereof we report a “super-combo” effect of multiwalled carbon nanotubes (MWCNTs) in poly (trimethylene terephthalate)/polypropylene (PTT/PP) blend system. MWCNTs act as a good reinforcing agent and compatibilizer in the otherwise immiscible PTT/PP blend. PTT/PP blends (with varying blend ratio and MWCNT loading) were melt mixed and later compression molded. The fabricated sheets were characterized for mechanical and morphological properties. Information regarding morphology was determined using scanning electron microscope (SEM) and transmission electron microscope (TEM). Dispersion of MWCNT in PTT was confirmed by the TEM images. Better understanding is in sighted by carrying out a correlation between mechanical properties with morphology, in-line with theoretical equations and selective dissolution experiments. Mechanical properties of all blend compositions were enhanced with the addition of 1 wt % MWCNTs, in which the blend having higher composition of PTT shows excellent mechanical properties. The addition of different MWCNTs loading in to the 90PTT/10PP composition shows a significant increase in Young's modulus and experimental values showed good alignment with theoretical values especially at lower filler loadings. Key findings from the morphology are in agreement with the mechanical properties and so we propose the super combo effect of MWCNTs as a compatibilizer and reinforcing agent for PTT/PP immiscible blend system. Through performed experiments and theoretical studies, we firmly believe that engineered composites with stabilized morphology will be a promising candidate for engineering materials with diverse applications.