FT-IR/UATR and FT-IR transmission quantitative analysis of PBT/PC blends

Polymer blends are produced to achieve properties that pure polymers are unable to. The qualitative analysis of these blends is not always satisfactory to point out failures in the final product and, therefore, the determination of their content might be required. The aim of this study is to develop quantitative methodologies using Fourier transform infrared spectroscopy (FT-IR), reflection mode with the universal attenuated total reflectance accessory (UATR) and transmission techniques, for the determination of the content of each polymer present in the polymer blend poly (butylene terephthalate) (PBT) and polycarbonate (PC). FT-IR/UATR presented better results using the relative band (A1772/A1716). FT-IR/UATR presented error of 2.30%, which is a little higher than the accuracy limit of the spectrometer (≤2%), but still adequate for industrial applications. •Polymer blends are produced to achieve properties that pure polymers are unable to.•The qualitative analysis of blends is very important to point out failures in the final product.•Quantitative methods were developed using FT-IR, in the MIR region, by reflection (UATR) and transmission.•The relative bands A1772/A1716 (PC/PBT) were used in both methodologies, the best result, was the reflection method (UATR).•The FT-IR/UATR error was 2.30%, slightly above the precision limit (≤ 2%), but the methodology is accurate.