Detection, identification, and quantification of polymer additives: a review of techniques, approaches, challenges, and a possible roadmap in analysis

Abstract

The type and concentration of additives in polymer systems play a crucial role in determining the physical, mechanical, and chemical properties of these materials, as well as influencing their processing and performance in end-use applications. However, polymer additive detection, identification, and quantification are challenging due to the very low concentrations used and the poor solubility of some additives in solvents required for testing. In addition, polymer degradation products can interact with the additives during testing. To address these challenges, various techniques have been developed. Each method offers unique advantages and challenges, including sensitivity, specificity, and limitations in the polymer systems to which it is applicable. Understanding the advantages and limitations of these methods is essential for selecting the appropriate technique for the polymer additive system under analysis. This article reviews the primary methods used for polymer additive detection, identification, and quantification, including Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, gas chromatography (GC), mass spectrometry (MS), high performance liquid chromatography (HPLC), carbon/hydrogen/nitrogen/sulfur (CHNS) analysis, inductively coupled plasma (ICP) analysis, energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). This review critically examines the challenges of qualitatively and quantitatively evaluating additive content using these methods, while highlighting their strengths and limitations, and how combinations of techniques can be used synergistically to enhance capabilities. This review aims to provide foundational insights and a potential roadmap for researchers and engineers who are beginning to explore polymer additives.