(362a) Characterizing Interfacial Thermal Transitions In Polymer Nanocomposites

Heated Tip atomic force microscopy (HT-AFM) allows for thermomechanical transitions to be locally determined, with nanoscale resolution. Here, HT-AFM is used in a scanning mode to activate a local transition at the polymer particle interface in a Poly(trimethylsilyl propyne) - Silica nanocomposite. Heated scanning ultimately resulted in debonding of the particle from the matrix. Consideration of the mechanism for debonding revealed both adhesive and deformative barriers. The existence of a significant deformative barrier suggests the technique is highly sensitive to the interfacial thermomechanical properties of the matrix. It was found that the impact force of the probe on the particle exhibits a stark transition at a temperature below that observed in the bulk material. The transition is attributed to enhanced mobility at the interface, which helps explain the enhanced properties of the resultant nanocomposite.