It is well known that either flow or nanoparticles can greatly increase the crystallization kinetics in thermoplastics, presumably by increasing the nucleation rate. Here we study the case of combined flow and nanoparticles to understand how these two effects interact. We utilize a recently developed rheo-Raman microscope to quantitatively correlate the elastic modulus and the crystalline structures associated with the conformational changes during crystallization subject to a combination of shear and nanoparticles in polycaprolactone (PCL) with cellulose nanocrystals (CNCs). First we demonstrate that PCL and cellulose nanocrystals CNCs can be well-compatibilized by replacing the Na+ of sulfated cellulose nanocrystals (Na-CNCs) with tetra-butyl ammonium cations and then melt mixing via twin-screw extrusion. Transmission electron microscope and high temperature melt rheology show that the modified CNCs were well dispersed in the polymer matrix. Combining rheo-Raman measurements we establish a correlation between mechanical, chemical and structural properties. For the present studies, we have used a kinetic parameter defined by Lichtenecker’s equation, a two phase composite model, to correlate the mechanical and Raman data, indicative of structural changes with addition of the filler particles.

Effect of nano-particles and flow on crystallization kinetics in polymer nanocomposites

254th National Meeting (2017)

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