1H and13C NMR Spectra of Highly Branched Poly(4-chloromethylstyrene). Signal Assignment, Structure Characterization, and a SCVP Kinetics Study

In this work, we present a detailed structural analysis of poly(4-chloromethylstyrene) (P(4-CMS)) by 1D and 2D NMR methods. A signal assignment and quantitative analysis of the different aliphatic structures of the polymer backbone were achieved. Combining signal integration of spectra taken in both C 6 D 6 and CD 2 Cl 2 as solvent, the content of terminal (T), vinyl-type linear (L V ), condensation-type linear (L C ), and dendritic (D) units and thus the degree of branching could be determined. The study is completed by a kinetics study of the polymerization of 4-CMS at 115 °C in chlorobenzene with CuCl/bpy as activator. The development of subunits is followed depending on vinyl group conversion and compared with a theoretical study of Müller et al. Obviously, the fractions of structural units cannot be predicted by a simple theoretical model due to the complexity of the mechanism of the atom transfer radical polymerization (ATRP). An increased content of L V units is rationalized by both a retarded deactivation resulting in multiple monomer addition steps and a higher reactivity of the secondary radical compared with the primary one.