A BN Aromatic Ring Strategy for Tunable Hydroxy Content in Polystyrene

Abstract

BN 2-vinylnaphthalene, a BN aromatic vinyl monomer, is copolymerized with styrene under free radical conditions. Oxidation yields styrene-vinyl alcohol (SVA) statistical copolymers with tunable hydroxy group content. Comprehensive spectroscopic investigation provides proof of structure. Physical properties that vary systematically with hydroxy content include solubility and glass transition temperature. BN aromatic polymers represent a platform for the preparation of diverse functional polymeric architectures via the remarkable reaction chemistry of C-B bonds.

Six-Membered Rings With Two or More Heteroatoms With at Least One Boron

“…5,[199][200][201] A BN aromatic ring strategy for preparation of poly(vinyl alcohol) derivatives via organoborane oxidation has recently been developed. 202 Six-membered CBN heterocycles have received considerable attention as potential hydrogen storage materials owing to favorable kinetics of H 2 release. 203 Moreover, the Lewis acidity of three-coordinate borone-containing heterocycles has prompted chemists to investigate the optical sensing of anions such as fluoride and cyanide ions.…”

Chain transfer to solvent in BN 2‐vinylnaphthalene radical polymerization

“…27 While clear-cut evidence that conventional SEC is inappropriate for characterization of PBN2VN molecular weight characteristics has not emerged, confidence in the SEC elugram would be bolstered by measuring molecular weight characteristics by another method. Unfortunately, neither 1 H NMR spectroscopy nor mass spectrometry have yet provided relevant data. The 1 H NMR spectrum of PBN2VN does not show clearly resolved resonances consistent with end groups, prohibiting estimation of number-average molecular weight.…”

“…3 BN2VN is a promising alternative to VAc, as BN2VN exhibits styrene-like radical reactivity (r 1 (St) = 2.4; r 2 (BN2VN) = 0.52) 5,6 and the C-B side chains can be oxidatively converted to hydroxyl (─OH) functional groups (Figure 1B). 1,[7][8][9] Conjugation with the aromatic BN naphthalene ring [10][11][12] is hypothesized to be critical to the closely matched St/BN2VN reactivity ratios, which is supported by comparison to the reactivity ratios of St with unconjugated monomers like VAc and di(isobutoxy) methylvinylsilane 13,14 (Figure 1C). Further evidence for the role of conjugation arises from Nishikawa's characterization of isopropenyl boronic acid pinacol ester (IPBpin) 15,16 as an electron-rich conjugated monomer, allowing the synthesis of styrene-methylvinyl alcohol statistical copolymers (fractional composition of methylvinyl alcohol, F MVA = 0.22) via side chain oxidation.…”

Photoinduced SET to access olefin-acrylate copolymers

“…A possible strategy to overcome the inherent differences in the reactivity of two monomers in radical copolymerization is to exploit a post-polymerization modification reaction that is specific for one type of monomer unit. [13][14][15][16][17][18][19] In this manner, copolymerization of two monomers with similar polymerizability can lead to polymeric precursors for copolymers with compositions and microstructures that are inaccessible by direct copolymerization. Indeed, post-polymerization methods [20][21][22][23][24] to produce polymers and copolymers containing olefins have been recently reported via either deoxygenation of poly(methyl acrylate) 25 or post-functionalization and subsequent grafting-from polymerization from polyethylene or polypropylene.…”