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Degradation processes driven by UV exposure, and manifested for example as polymer gloss loss or coating failure, are generally accelerated at elevated temperature, or conversely, their rates are reduced at lower temperature. In a weathering environment comprising IR irradiance, IR transmitting black resin tends to be cooler than an otherwise comparable sample of IR absorbing black resin. Accordingly, slower UV-driven degradation, and longer weathering lifetime, is expected for IR transmitting black resin relative to IR absorbing black resin, commensurate with their temperature difference in a given weathering environment and the sensitivity of the degradation process to temperature.

Polycarbonate (PC) glazing as a one-for-one glass replacement offers a 50% weight reduction, but exhibits several dB lower sound transmission loss (STL) in the low frequency range where tire and engine noise are dominant. In the high frequency range where wind noise is dominant, PC glazing offers an STL at least comparable to its glass counterpart, and an STL exceeding glass when this frequency range encompasses the glass coincidence frequency. However, a key value proposition of PC glazing is the opportunity for feature integration afforded by the injection molding process generally used for forming such glazing. Two-component (2K) molding fuses a second shot of plastic material behind, and along the perimeter of, the transparent PC first shot. This second shot can incorporate features and implement functions that require additional components attached or peripheral to a glass version.

Coated polycarbonate (PC) is a leading engineering thermoplastic used in automotive glazing for replacing laminated glass. Mechanical properties of multi-layer coating systems were investigated using a nano-indenter and the fracture behavior of coating during nano-scratch was studied employing scanning electron and atomic force microscopy. A set of coated samples was prepared, with two layers, namely Layer-1 and Layer-2. Layer-1 was applied directly to the PC substrate and used as adhesion promoter. Layer-2 was prepared with different mechanical properties. Abrasion performance of the coated system was characterized using an ASTM abrasion test methodology. Regression analysis was performed to establish correlation between the mechanical properties of the coating system and its abrasion performance. Fracture behavior of the coating systems and their plausible relationship with abrasion performance was also discussed.

Previous papers by the present authors described use of computational fluid dynamics (CFD) to quantify the effect of glazing thermal conductivity on steady-state heating, ventilation and air-conditioning (HVAC) load under wide-ranging climate and state of motion scenarios, and to estimate the significance of this effect for electric battery performance. The CFD simulations yielded the total heat transfer between the ambient and the cabin of a model car, including radiative and convective heat transfer. The five-fold lower inherent thermal conductivity of polycarbonate relative to glass was found to reduce steady-state HVAC load by several percent in all scenarios, leading to reduced greenhouse gas emission or increased electric range, according to the type of vehicle.

Heat transfer between the ambient and the air in a vehicle cabin determines the nominal steady state load on the vehicle's heating, ventilation and air conditioning (HVAC) system, a significant factor for vehicle efficiency and greenhouse gas emissions. This paper highlights the effect of glazing (i.e. window) thermal conductivity on steady state heat transfer, with high and low thermal conductivities represented respectively by monolithic glass and standard polycarbonate. Computational fluid dynamics simulations are summarized for a model car cabin including HVAC vents, interior seating, and a rooflite. Passenger and moisture effects are not included. Monthly temperature and radiation data for Phoenix, Arizona and Minneapolis, Minnesota are used to define hot and cold climate scenarios.

Reduced battery discharge rates in electric vehicles (EV) tend to extend single-cycle range as well as battery lifetime. Vehicle features that tend to reduce battery discharge rate thus support viability of EV. Of special interest are features that reduce the load on the heating, ventilation and air conditioning (HVAC) system since that system can in turn impose a significant load on EV batteries. A companion paper quantifies the effect on steady state nominal HVAC load of glazing (i.e. window) thermal conductivity using Computational Fluid Dynamics (CFD) to simulate heat transfer between the ambient and the air in a model car cabin when the cabin air is maintained at a comfortable temperature. For hot and cold climate, and for stationary and moving cars, reductions in HVAC load resulted from replacing a monolithic glass backlite and rooflite with polycarbonate (PC), the latter with a five-fold lower inherent thermal conductivity.