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

Abstract

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.

Main-chain/side-chain type phosphine oxide-containing reactive polymers derived from the same monomer: controllable RAFT polymerisation and ring-opening polycondensation

“…28 In addition, the signals for the styrenic structure were identified individually according to the 1 H NMR spectrum of VBzBHPO. 50 A single peak was found at 38.54 ppm in the 31 P NMR spectrum (Fig. 1a, insert), which was quite different from the phosphorus signal of VBzBHPO (42.96 ppm, s, DMSO-d 6 ).…”

“…4-Vinylbenzyl-bis(hydroxymethyl) phosphine oxide (VBzBHPO) and tris(2-cyanoethyl) phosphine (TCP) were synthesized in our laboratory. 50,51 Bis (tetrabutylammonium) sebacate (TBAS) and n-butyl benzyl trithiocarbonate (BBTC) were synthesized according to the literature methods. [52][53][54] All other chemical solvents and reagents were used as received: NaOH (>96%, Sinopharm), sulfuric acid (95%-98%, Sinopharm), butanedioic acid (>99%, Sinopharm), triethylamine (>99%, Sinopharm), diethylamine (DEA, 98%, Aladdin).…”

“…VBzBHPO was first synthesized from tetrakis(hydroxymethyl) phosphonium chloride (THPC), a commercial intermediate of PH 3 tail gas during the production of sodium hypophosphate. 50,55 According to the reaction of tri(hydroxymethyl)ethane with epichlorohydrin reported in the literature, 56 the NaOH/DMSO system proved to be an efficient choice for the reactions between hydroxyl groups and epichlorohydrin. During a similar reaction process, the mixture remained turbid owing to the poor DMSO solubility of the reactant NaOH or NaCl byproduct.…”

“…Substitution of the hydroxyl protons by the oxirane groups was clearly established by NMR analysis. Compared with the FT-IR spectrum of VBzBHPO, 50 a characteristic band at 947 cm −1 resulted from the vibrations of the epoxy rings (C-O) that were produced by the reactions of hydroxyl groups and epichlorohydrin. The broad absorption peak at 3435 cm −1 was assigned to the stretching vibrations of OH groups in water, which showed the hydrophilicity of the monomer.…”

“…In our early report, a novel phosphine oxide-based styrenic monomer VBzBHPO, which contains two hydroxyl groups, has been designed and synthesized as a derivative of PH 3 tail gas. 50 In order to facilitate the post-polymerisation modification and increase the modification density, a brand new di-epoxy monomer was synthesized through the reaction between VBzBHPO and epichlorohydrin. In this approach, the designed monomer can be polymerized either in a chain-growth or in a step-growth manner to achieve both side-chain and mainchain type poly( phosphine oxide)s from one monomer.…”