Novel low shrinkage thermoplastic olefins with cool pigments additives: Desing, preparation and performance evaluation

Official URL: https://risc01.sabanciuniv.edu/record=b2579523_(Table of contents)

Energy consumption due to the excessive use of air conditioning especially in hot summer days, in buildings and vehicles is one of the most important considerations about environmental health. Particularly, the heat accumulated in the inner black parts used in vehicles due to the absorbed solar light highly contributes to the use of excessive air conditioning and causes the overheating inside the vehicle. Thermoplastic olefins (TPOs) is the most commonly used polymeric material in automotive industry, in these inner parts such as trim and dashboards, due to their better elastomeric properties. Another challenging problem during the production of these materials is to control the mold shrinkage of TPOs since these parts have very high aspect ratio. So, this thesis treats these two problems and try to find an optimum combined solution. The aim is to obtain thermoplastic olefin materials having black color with cool surface and low mold shrinkage. Therefore, first part of the thesis engaged in preparation of TPO formulations with low mold shrinkage by melt blending plastomers which have various physical/mechanical properties into a polyolefin phase. As a result of the structure-function relationship study of plastomers, the TPO material with lowest mold shrinkage is obtained with the incorporation of plastomer having lowest crystallinity. Then, second part of the thesis focused on generation of cool black surface by incorporation of cool black pigments which have near-infrared (NIR) reflective and transparent properties into the formulation of TPO material with lowest mold shrinkage. After evaluation of surface temperature, reflectance and physical/mechanical properties, MIX_5 is considered as the optimum TPO compound having 28.5% decrease in surface temperature compared to conventional black pigments and with mold shrinkage values in parallel (0.61%) and perpendicular (0.11%) to flow direction.