The role of microcrystalline structure on the temperature-dependent thermo-optical properties of semi-crystalline thermoplastics and non-invasive temperature measurements

The relation between the microcrystalline structure of unfilled semi-crystalline polyolefin (PO)-based polymer and its thermo-optical characteristics was studied under room and varying temperatures. The temperature-dependence of its optical properties was observed in NIR range while this effect vanishes after certain wavelengths in MIR range. This is critical in order to determine a methodology for an accurate non-invasive IR thermography on the polymer surface. The preliminary IR thermographic analyses showed that accurate surface temperature measurements may not be simply performed on the PO-based polymers due their optical characteristics. Nomenclature D p Optical penetration depth, µm T λ Transmittance R λ Reflectance D λ Scattering coefficient, m-1 Φ λ Radiative flux β λ Extinction coefficient, m-1 κ λ Absorption coefficient, m-1) (T  Integrated absorption coefficient, m-1