3.6.1 Infrared Spectroscopy

Swaraj and Bengt [82] used infrared spectroscopy to determine epoxy groups in methylmethacrylate - glycidyl methacrylate copolymers.

The infrared analysis was performed on dried potassium bromide pellets containing 0.5 mg sample in 200 mg potassium bromide. An infrared spectrum of a methyl methacrylate - glycolymethyacrylate copolymer is shown in Figure 3.7. The peaks at the wave numbers 11.02 and 5.82 ?m are the most suitable ones for analysis of epoxy and carbonyl groups, respectively. Using the base line density method, the values of the absorbances at 11.02 and 5.82 ?m have been determined in triplicate. The average values of the absorbances, their ratio and the glycidylmethylacrylate mole fraction determined chemically are presented in Table 3.10.

Figure 3.7: Infrared spectrum of methylmethacrylic acid glycol methyl-acrylate copolymer containing 62.3 mole% of glycolmethylacrylate.
(Reprinted with permission from S. Paul and B. Ranby, Analytical Chemistry, 1975, 47, 8, 1428. 1975, ACS) [82]