Nanomechanics and Origin of Rubber Elasticity of Novel Nanostructured Thermoplastic Elastomeric Blends Using Atomic Force Microscopy

Abstract

PeakForce quantitative nanomechanical mapping is an advanced atomic force microscopy (AFM) technique for measuring the mechanics of a sample surface by probing at the nanoscale. This nanomechanical mapping is performed in novel nanostructured thermoplastic elastomer (TPE) and thermoplastic vulcanizate (TPV) consisting of nanolevel dispersion of fluoroelastomer phase (60-80 nm) in the continuous polyamide matrix. Both in the case of TPE and TPV, elastic modulus and adhesion force (between the tip and sample surface) from the continuous matrix phase to the dispersed rubber particle through the nanometric interface (4-5 nm) are analyzed. The effect of dynamic vulcanization on the nanomechanical properties of the interface and the dispersed rubber phase of the blends is discussed. The origin of rubber elasticity in thermoplastic elastomeric blends in spite of the plastic as the continuous phase is proposed. It was shown for the first time that the interconnected dispersed rubber phase through the thin rubber ligament of 4-12 nm width in the thermoplastic matrix significantly contribute to the rubber elasticity in TPE and TPV. The PeakForce atomic force microscopy technique was performed on novel nanostructured thermoplastic elastomeric blends to quantify elastic modulus and adhesion force of rubber, plastics and their interfaces. It is observed for the first time that a network-like distribution of nanometric rubber ligaments within the plastic matrix is responsible for the origin of rubber elasticity of these blends.