Visible Light-Induced Grafting from Polyolefins

Abstract

Polyethylene-graft-poly(tert-butylacrylate) (PE-g-PtBA) copolymers were prepared by using a combination of ring-opening metathesis polymerization (ROMP), hydrobromination, and visible light-induced free radical polymerization. First, cis-cyclooctene was polymerized via ROMP in the presence of a chain transfer agent and quantitatively hydrobrominated. Poly(tert-butyl acrylate) (PtBA) chains were then grown via a grafting from approach from the Br-substituted linear poly(ethylene) (PE) backbone using dimanganese decacarbonyl (Mn2(CO)10) under visible light. The effect of Mn2(CO)10 concentration and irradiation time on the grafting density and efficiency was evaluated. The tert-butyl acrylate (tBA) esters of the graft copolymers were hydrolyzed into acrylic acid functionalities by acidolysis to obtain hydrophilic polyolefins. The precursor polymer, graft copolymer, and hydrolyzed polymer were characterized by 1H and 13C NMR, Fourier transform infrared, atomic force microscopy, and contact angle measurements.

Polypropylene-based graft copolymers via CuAAC click chemistry

“…Due to the absence of polar groups, semi-crystalline morphology, resistance to polar or ionic chemicals and limited chemical substitution, oxidation and free radical reactions, these modifications are quite challenging and usually are difficult to maintain [5]. There are two main modification methods in the literature: (i) direct copolymerization of either α-olefin [6,7] or polar monomers [8,9] and (ii) chemical modification of preformed polymers [10,11]. For example, antibacterial [12], antifouling [13] and hydrogen storage [14] properties of polypropylene were enhanced via surface-initiated atom transfer radical polymerization [15].…”

New Photochemical Processes for Macromolecular Syntheses

“…Its utilization as a photoactive system for the fabrication of wide range of macromolecular structures deserves intense consideration from the practical point of view [23][24][25]. We have reported that the related visible light initiating systems involving both radical and cationic modes can be applied in the synthesis of various macromolecular structures, such as telechelic polymers [26], block [27,28] and graft copolymers [29], and hyperbranched polymers [30]. Scheme 3 shows the overall uses of dimanganese decacarbonyl in macromolecular syntheses.…”

Visible Light-Induced Atom Transfer Radical Polymerization for Macromolecular Syntheses

“…We have previously shown that manganese based radical generation process can successfully be employed in different modes of polymerization processes including radical promoted cationic polymerization (51), mechanistic transformation (52,53), radical coupling (54), hyper-branching (55) and grafting from polyolefines (56). Recent studies from our laboratory showed that this chemistry can be used as a photoredox catalyst system for the ATRP of vinyl monomers such as methyl methacrylate, methyl acrylate and styrene (57).…”