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.

BN Polystyrenes: Emerging Optical Materials and Versatile Intermediates

“…An optical assay based on the selective absorption at 320 nm of the BN naphthalene side chain confirmed BN2VN incorporation into the copolymer at levels commensurate with the feed ratio. 31 Reactivity ratios for BN2VN and styrene were determined from low conversion freeradical copolymerizations using both traditional linearization methods and modern nonlinear least-squares statistical analysis (Table 3 and Figure 2). 32 The reactivity ratios (r 1 (BN2VN) = 0.423 and r 2 (St) = 2.30) indicated a statistical copolymerization.…”

“…We developed a two step, multigram scale synthesis of BN2VN (55% overall yield, Scheme 2). 30,31 2-Aminophenethyl alcohol 5 was converted to 2vinylaniline 6 in 63% yield by vacuum distillation in the presence of potassium hydroxide. 43 Condensation with potassium vinyltrifluoroborate provided BN2VN in 88% yield.…”

Organoborane Strategy for Polymers Bearing Lactone, Ester, and Alcohol Functionality

“…Indole and B(OH) 3 arise from oxidation of the internal C−B bond of the initially formed BN naphthol and were also the byproducts observed in hydrogen peroxide-mediated oxidations (see Figure S6 for the proposed mechanism of Me 3 NOmediated oxidation of BN2VN copolymers). 12,14 While signatures of oxidation were present, structural characterization was not consistent with PVA-co-PMMA. In the following discussion, spectra of oxidized PBN2VN 30 -co-PMMA 138 (P1) are shown as a representative sample.…”

“…12,13 Nonlinear least-squares (NLLS) statistical analysis showed a dramatic narrowing of the styrene− BN2VN reactivity ratios compared to styrene−VAc (r 1 (St) = 2.3, r 2 (BN2VN) = 0.42; r 1 (St) = 55, r 2 (VAc) = 0.01). 10,13 The side chain C−B bond of BN2VN polymers is converted to a C−OH bond with alkaline hydrogen peroxide (H 2 O 2 /NaOH), which is effective for the synthesis of PVA-r-PS 12 and syndiotactic PVA (sPVA) 14 from BN2VN-derived precursors. Nishikawa and Ouchi recently described a similar approach to poly(α-methyl vinyl alcohol) via isopropenyl pinacol boronate polymerization.…”

“…The unique absorption at 320 nm of the BN naphthalene chromophore facilitated quantitative determination of the BN2VN content in BN2VN−2VN and BN2VN−St copolymers. 11,12 A similar assay was developed for BN2VN−MMA copolymers (Figures S1 and S2). We find good agreement between mol % BN2VN in the feed compared to isolated samples obtained at high conversion (Table 1).…”