Synthesis and characterization of benzodioxinone mono-telechelics and their use in block copolymerization.

Cumali Çelik

doi:10.3906/kim-2104-22

Abstract

Poly(methyl methacrylate) (PMMA) and poly(ethylene glycol) methyl ether (mPEG)-based monotelechelics were quantitatively prepared by copper (I)-catalyzed azide/alkyne cycloaddition (CuAAC) click reactions using azido-terminated polymers and alkyne functional benzodioxinones. The monotelechelic containing dimethyl moities (2,2-dimethyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) was heat-sensitive, whereas the monotelechelic containing diphenyl moieties (2,2-diphenyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) was UV light sensitive. Based on the FT-IR, 1H-NMR, and GPC investigations, the CuAAC click reactions enable the quantitative syntheses of monotelechelics under mild conditions. Moreover, the photosensitive mPEG-based monotelechelic was further utilized for the block copolymer synthesis upon UV-light irradiation. The photoinduced acylation of mPEG monotelechelic consist of (2,2-diphenyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) in the presence of hydroxy-terminated poly(epsilon caprolactone) enabled the successful block copolymer formation.

Highlights

Telechelic polymers are macromolecules consisting of reactive groups at both chain ends, and they are widely used as building blocks for numerous macromolecular architectures including block and graft copolymers and star polymers as well as chain extenders, cross-linkers for polymer networks [1]
Benzodioxinone chemistry has been utilized in homopolymerization, block, and graft copolymerization and cross-linking reactions for the construction of various macromolecular architectures including homopolymer block copolymers, graft copolymers and polymer networks
Thermally (Alkyne-DMe-Bd) and photochemically (Alkyne-DPh-Bd) active alkyne functionalized benzodioxinones were firstly synthesized by etherification reactions of propargyl bromide with either 5-hydroxy-2,2-dimethyl-4h-benzo[d] [1,3]dioxin-4-one or 5-hydroxy-2,2-diphenyl-4h-benzo[d][1,3]dioxin-4one

Summary

Introduction

Telechelic polymers are macromolecules consisting of reactive groups at both chain ends, and they are widely used as building blocks for numerous macromolecular architectures including block and graft copolymers and star polymers as well as chain extenders, cross-linkers for polymer networks [1]. Various macromolecular structures including block and graft copolymers and polymer networks were prepared via benzodioxinone chemistry upon UV irradiation at ambient temperature [10,16,17,18,19,20,21,22,23,24]. Firstly both heat- (2,2-dimethyl-5-(prop-2-yn-1-yloxy)-4h-benzo[d][1,3] dioxin-4-one) and photo-sensitive (2,2-diphenyl-5-(prop-2-yn-1-yloxy)-4h-benzo[d][1,3]dioxin-4-one) benzodioxinones (Alkyne-DPh-Bd and Alkyne-DMe-Bd) were successfully synthesized using modified literature. These compounds were installed on the terminal position of both azido-functionalized poly(methyl methacrylate) and poly(ethylene glycol) methyl ether in order to get their mono-telechelics via CuAAC click chemistry. The mild UV irradiation of the obtained photosensitive-monotelechelic (Alkyne-DPh-Bd) in the presence of monohydroxyl-functionalized PCL resulted in corresponding block copolymer nearly quantitative yield

Experimental

Results and discussion

Conclusion