pps proceeding - Abstract Preview
pps proceeding
Symposium: S02 - Polymer Blends and Alloys
Poster Presentation
 
 

Morphology, Crystallization Kinetics in Ternary Polymer Blends: Evaluating the Influence of Surface Functionalized Carbon Nanotubes

Kar Goutam Prasanna (1)*, Bose Suryasarathi (1)

(1) Indian Institute of Science, Bangalore - Karnataka - India

Structural properties, evolution of morphology and crystallization kinetics in immiscible polymer blends filled with multiwall carbon nanotubes (MWNTs) in the droplet phase were systematically investigated in this study. By grafting suitable macromolecules, that can drive the MWNTs to the droplet phase, allowed the understanding of the rate of nucleation and growth of the semicrystalline matrix in droplet-filled blends in contrast to matrix-filled blends. By blending 90 wt% of PVDF with 10 wt% ABS, matrix-droplet morphologies were generated and by grafting (styrene acrylonitrile) SAN onto MWNTs, the localization of the nanotubes was tuned to fill the droplet phase which otherwise prefers the matrix phase (here PVDF); driven by thermodynamics. The evolution of morphology under quiescent annealing conditions was assessed by SEM. The blends with SAN-g-MWNTs also coarsened as a function of time similar to neat blends however, to a lesser extent. Although, droplet laden MWNTs did not suppress coarsening in the blends but it still improved the tensile properties when compared with the neat blends. The fold surface free energy (as evaluated from isothermal crystallization kinetics) was estimated to be less in case of blends with SAN-g-MWNTs in contrast to blends with only MWNTs. This was attributed to the fact that matrix (here PVDF) filled with MWNTs experiences faster crystallization rate due to heterogeneous dispersion of nucleating agents (here MWNTs) in the matrix. However, when the nanotubes were mostly localized in the amorphous dispersed phase (here ABS), PVDF experienced similar crystallization behavior like the neat PVDF/ABS blends. Taken together, our study demonstrates that lower amount of energy is required for the arrangement of PVDF chains into the crystal lattice upon cooling from the melt state and accelerate the crystallization process when the heteronucleating agents are localized in the matrix phase than when they are localized in the amorphous phase.