Overview

A variety of instrumental techniques have been used to determine functional groups in polymers and to elucidate the detail of polymer structure. These include infrared spectroscopy, near-infrared spectroscopy including Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and proton magnetic resonance (PMR) spectroscopy, chemical reaction gas chromatography, pyrolysis gas chromatography (PGC), pyrolysis gas chromatography mass spectrometry, pyrolysis NMR spectroscopy, X-ray fluorescence spectroscopy (XRFS), and also newer techniques such as time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), tandem mass spectrometry (MS-MS), matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS), microthermal analysis, atomic force microscopy (AFM), and various X-ray methods including scanning electron microscopy (SEM) energy dispersive analysis using X-rays (EDAX).

Functional groups that may have to be determined include: hydroxy, carbonyl, carboxyl, alkyl, aryl, alkoxy, oxyalkylene, nitrile, ester, amino, nitro, amide, amido, imino, and epoxy groups. Comonomer ratios, isomers, and short-chain branching are all structural features of polymers that may have to be elucidated in order to obtain a complete picture of polymer structure.