Thermophysical property characterization of novel polymer and composite systems

Process temperature profiles of a two-component rigid poly(urethane-isocyanurate) foam system are studied and compared with the predictions of a one-dimensional numerical simulation. The model is based on experimentally determined thermophysical properties including thermal diffusivity, enthalpy of reaction and rate of reaction. Temperature dependent heat capacity, reaction kinetics and heat of reaction are evaluated using temperature scanning DSC. The simulations accurately predict experimental results. The simulations allow the determination of demold time on process conditions including feed temperature, mold temperature and sample thickness. Transport behavior is investigated. The heat and momentum transfer behaviors of the flowing and reacting polymer system are modeled using a computational fluid dynamics (CFD) approach. Two models are developed and compared with the experimental results in order to provide insight into the optimization of processing. The models allow prediction of the temperature profiles under a variety of operation conditions.; Thermal energy storage (TES) composite that combines TES and structural functionality is described. The composite is encapsulation of low-melt-temperature phase change materials (PCM) such as paraffin wax in polymer matrix. Styrene ethylene butylene styrene (SEBS) block copolymer is chosen as matrix material due to its excellent chemical and mechanical properties. The PCM provides the energy storage function via the solid-liquid latent heat effect. The resulting composite exhibits “dry” phase transition in that fluid motion of the PCM, when it is in the liquid phase is inhibited by the structure of the polymer matrix mentioned. The polymer matrix is formulated to provide structural functionality. The latent heat, effective thermal conductivity and structural modulii of composite are measured.