FTIR spectroscopic studies on the interfacial reactions of oxazoline-functionalized polymers

The interfacial reaction of immiscible polymeric systems containing oxazoline and carboxylic acid groups, respectively, has been studied by FTIR spectroscopy and FTIR microscopy. A poly(butadiene-co-acrylonitrile) rubber, where the nitrile groups are partially converted to oxazoline groups, is thermally annealed in a two-layer specimen with poly(ethene-co-methacrylic acid). The formation of the esteramide in the interface is measured quantitatively by FTIR difference spectroscopy. Evaluating the formation of the amide I band leads to reaction rate constants ranging from 0.0125 to 0.022 s -1 in the temperature range from 170 to 230 °C. It can be shown by FTIR microscopy that this system is immiscible because there is no interdiffusion across the interface. Also the formation of an esteramide in the interfacial reaction of the system poly-(ethene-co-methacrylic acid)/bis(1,3-oxazoline-2-yl)-terminated poly(dimethylsiloxane) is monitored qualitatively by FTIR spectroscopy.