Hydrophilic graft modification of a commercial crystalline polyolefin

Abstract

Hydroxy-functionalized isotactic poly(1-butene) was synthesized using transition metal-catalyzed regioselective CÀ ÀH borylation at the side chain of the commercial polyolefin and subsequent oxidation of the boronic ester functionality. Functionalization up to $ 19 mol % of the termini of the ethyl side chain occurred without significant side reactions that could alter the polymer chain length. Esterification of the hydroxy group in the polymer with 2-bromoisobutyl bromide generated a side chain-functionalized polyolefin macroinitiator. Atom transfer radical polymerization of tert-butyl acrylate from the macroinitiator produced a high molecularweight graft copolymer of the polyolefin, isotactic poly(1-butene)-graft-poly(tert-butyl acrylate) (PB-g-PtBA). Finally, the hydrolysis of the tert-butoxy ester group of PB-g-PtBA created an amphiphilic polyolefin, isotactic poly(1-butene)-graft-poly(acrylic acid), which contained a short carboxylic acid-functionalized polymer block at the side chain. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: [3533][3534][3535][3536][3537][3538][3539][3540][3541][3542][3543][3544][3545] 2008

Synthesis and Characterization of Semicrystalline Polyethylene‐graft‐Poly(acrylic acid) Copolymers

“…This is in contrast to the findings of Bae et al, who reported a decrease in both the T m and X c upon chemical hydrolysis of PB-g-PtBA materials. [13] We also observed a decrease in the melting transition and a more pronounced decrease in crystallinity for the AA grafts prepared via the thermal treatment. This is illustrated by comparison of entries AA3 and AA4, which reveals that the thermolysis product has a slightly lower X c (13 vs. 16%), and a significantly lower T m (93 vs. 125 8C).…”

“…13 C solid-state NMR spectra were obtained using a Bruker Avance 300 MHz spectrometer operating at 50.3 MHz for 13 C. A 4 mm double-tuned magic-angle spinning (MAS) probe head from Bruker was used, along with a 4 mm ZrO 2 rotor and a kel-F cap. The sample was spun at 10 kHz.…”

“…[12][13][14] In one report, commercially available isotactic poly(1-butene) was transformed into poly(1-butene)-graft-poly(acrylic acid) through a series of functionalization reactions, followed by an atom-transfer radical polymerization (ATRP). [13] First, hydroxylated polybutene or PB-OH was produced via a rhodium-catalyzed C-H bond activation/ borylation in the presence of bis(pinacolato)diboron, followed by an oxidation reaction. PB-OH was then treated with bromoisobutyryl bromide to yield a polybutene macroinitiator.…”

“…Subsequently, the tBA moieties were converted into acrylic acid units through chemical and thermal means to generate PE-graft-PAA copolymers. The increased hydrophilicity of the resulting materials was verified by ATR-IR, solid-state 13 C NMR spectroscopy, contact angle measurements, and TGA. copolymers with a random distribution of AA units.…”

Recent Advances in the Synthesis and Applications of Organoborane Polymers

“…They found that polypropylene can be selectively functionalized at the pendant methyl groups with B 2 pin 2 (Pin ¼ pinacolato) in the presence of Cp*Rh(C 6 Me 6 ) as the catalyst (2, Scheme 1b) [21]. Similar methods were developed for the functionalization of LLDPE and for isotactic poly(1-butene) (up to 19% borylation) [22,23]. Bae and coworkers investigated the borylation of atactic, isotactic, and syndiotactic polystyrene in the presence of an Ir catalyst (e.g., [IrCl(COD)] 2 /dtbpy) and achieved high degrees of functionalization (3, up to 42% borylation) [24].…”