Modification of polymers using multilayered “smart pellet” additives: Part I

A multilayer “smart pellet” additive composed of layered polymers, and capable of exfoliating in a manner similar to that of smectite clays, was demonstrated to be an effective reinforcing agent for bulk polymers processed in the melt. Polysulfone (PSF) and Ethylene-octene (PEOC-1) copolymer were chosen as one of the model systems. PSF/PEOC-1 smart pellets were added to PEOC-1 as masterbatches during injection-molding. This methodology allowed for high glass transition temperature PSF to function as a reinforcing agent during injection-molding of matrix polymers processed below their glass transition temperature. Mechanical properties of the composites were studied by performing tensile and flexural tests. Tensile modulus was fitted to the Halpin-Tsai model, and this model was used to predict the optimum tensile modulus that PSF/PEOC-1 smart pellets could achieve. The morphology of smart pellet and polymer composites were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical microscopy (OM). The PSF layers were observed to resemble clay platelet morphology in PEOC-1 matrix.