Phosphine Oxide-Containing Multifunctional Polymer via RAFT Polymerization and Its High-Density Post-Polymerization Modification in Water

Reactive polymers with two or more reactive groups in each repeat unit were less reported, and these kinds of polymers were regarded as useful precursors for further multifunctionalization. Here, an alkali-soluble polymer with the bis(hydroxymethyl)phosphine oxide pendant group was first prepared by reversible addition–fragmentation transfer (RAFT) polymerization from a phosphine-containing monomer, namely (4-vinylbenzyl)-bis-hydroxymethyl phosphine oxide (VBzBHPO). The well-defined homopolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel permeation chromatography. The molecular weights of both homopolymers and block polymers can be designed by changing RAFT polymerization parameters while still maintaining the narrow molecular weight distributions (mostly M w / M n < 1.2). The linear polymerization kinetics and successful chain extension polymerization with styrene or VBzBHPO confirmed the features of controlled/living radical polymerization. Attractively, the resulting polyVBzBHPO showed high solubility in alkaline solution but only lightly swelled in pure water. Such a distinguishing feature of the polymer material provided the possibility of carrying out post-polymerization modification in water with high functionality density and high modification efficiency.