Synthesis and Aqueous Solution Properties of an Amino Bisphosphonate Methacrylate Homopolymer via RAFT Polymerization.

Panagiotis Falireas,Ghislain David,Claire Negrell

doi:10.3390/polym10070711

Abstract

The present contribution reports on the synthesis via reversible addition-fragmentation chain transfer (RAFT) polymerization of a methacrylate derivative bearing an aminobisphosponate moiety as a pendant group, namely, ethyl N,N-tetramethylbis(phosphonate)-bis(methylene) amine methacrylate (MAC2NP2). The polymerization was performed by the use of cyanoisopropyl dithiobenzoate as chain transfer agent at 70 °C in various solvents with different polarities including N,N-dimethylformamide, acetonitrile, tetrahydrofuran, and in bulk. Best results were obtained in N,N-dimethylformamide where higher conversions and polymerization rates were noticed. The successful hydrolysis of the phosphonate ester groups was performed using bromotrimethylsilane with excellent yields leading to the formation of highly water soluble and pH-responsive polymers. Finally, a preliminary solution behavior study was carried out by investigating the aqueous solution properties of synthesized amino bisphosphonate methacrylate homopolymers and their phosphonic acid analogs via potentiometric titration and zeta potential measurements.

Highlights

It is well known that phosphorus-based polymers represent a unique class of materials, which exhibit exceptional and unique properties, they have gained wide appeal and interest for scientific and industrial research within the last decades
The present study reports on the synthesis and characterization of an amino bisphosphonate methacrylate with a C2 spacer and polymerization thereof via reversible addition-fragmentation chain transfer (RAFT)
The polymerization of MAC2 NP2 was performed under RAFT conditions using CPDB as the chain transfer agent in the presence of AIBN at a constant molar ratio of CPDB/AIBN = 3 at 70 ◦ C in

Summary

Introduction

It is well known that phosphorus-based polymers represent a unique class of materials, which exhibit exceptional and unique properties, they have gained wide appeal and interest for scientific and industrial research within the last decades. Atom transfer radical polymerization (ATRP) and RAFT have been widely used for the controlled polymerization of monomers carrying phosphates [16,17,18], phosphinic acids [19,20], phosphonic acids [21], and phosphonates [12,22,23,24,25,26] as pendant groups The latter polymerization method has been one of the most effective and versatile methods which allows the Polymers 2018, 10, 711; doi:10.3390/polym10070711 www.mdpi.com/journal/polymers

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Results

Conclusion