Proton Magnetic Resonance Study of Poly(p-chlorostyrene) of Low Molecular Weight

Poly(p-chlorostyrne) samples of relatively low molecular weight (average degrees of polymerization (‾DP): 15, 24, and 46) were prepared by radical polymerization and their PMR spectra were observed in the temperature range 5–88 °C. When the temperature was elevated, the absorption of the methyne proton moved to lower field and the half height width for the absorption of the ortho proton decreased more remarkably than that of the meta proton. The absorption of the ortho proton of one polymer sample (‾DP: 15) showed an anomalous broadening. These features of the observed spectra were interpreted in terms of ring current shielding by aromatic side groups, and the conformations of the polymer are discussed.