In this paper, we report multivariate analyses, such as principal component analysis and partial least-squares regression, of NMR spectra of poly(N-isopropylacrylamide)s [poly(NIPAAm)s]. Principal component analysis successfully interpreted the assignments of NMR spectra of poly(NIPAAm)s in terms of stereostructures for the methine carbons at triad levels and for the methylene protons at tetrad levels. Furthermore, triad tacticity was successfully predicted by partial least-squares regression of 1 H NMR spectra of the methine and methylene groups, although the low resolution of the signals of the methine protons confines determination of tacticities by conventional methods to the diad levels. Consequently, it is assumed that chemometric approaches are useful for assigning NMR spectra in terms of stereostructures and for predicting tacticity distributions.

Isotactic-rich poly(N-vinyl-2-pyrrolidone) was successfully prepared by radical polymerization of N-vinyl-2-pyrrolidone assisted by diethyl l-tartrate (l-EtTar) at low temperatures.