Telechelic polymers by living and controlled/living polymerization methods

The first part of this review critically examines the various attempts to prepare macromonomers: Anionic and cationic polymerization for synthesizing living polymers have been preferred whenever possible but two-step radical polymerizations making use of efficient transfer agents have also been applied.

Macromonomers: Synthesis, characterization and applications

Poly(ethylene oxide) macromonomers carrying p-vinylbenyl and methacrylate end-groups were prepared by the anionic polymerization of ethylene oxide followed by reactions with p-vinylbenzyl chloride and methacryloyl chloride, respectively. Radical copolymerization with styrene (M1) in tetrahydrofuran at 60°C was carried out to give the macromonomer’s relative reactivity (1/r1), which decreased by a factor as much as about 1/2 with increasing degree of polymerization to about 100. This is discussed in terms of the kinetic excluded volume effect but by taking into consideration the generally repulsive interaction between different polymer chains and/or some different solution behavior of the polymers. These should be important factors in copolymerization involving the macromonomer.

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Reactivity of Poly(ethylene oxide) Macromonomers in Radical Copolymerization

Macromonomers are linear polymeric o r oligomeric species which, because of the presence of a reactive end group, have the potential either to polymerize with themselves or with comonomers. The reactive group is most commonly a vinyl group that can participate in free radical polymerization, but any polymerizable end group, such as epoxy, bis-hydroxy, etc., is sufficient for the molecule to be classified as a macromonomer. The words “macromer” and “macromonomer” are often used interchangeably, although the former term was introduced originally as a trademark of CPC International to describe the macromonomers discovered by Milkovich [1].

Reactivity of macromonomers in free radical polymerization

In this review we summarize and discuss the kinetic data of the homogeneous radical polymerization of macromonomers. We present kinetic data of radical polymerization of macromonomers. We present kinetic data of radical polymerization of hydrophilic or amphiphilic macromonomers whih are miscible or partly soluble in water and which associate and form organized structures. In addition homopolymerizations of oil-soluble macromonomers are also presented and discussed. Effects of the initiator concentration, the macromonomer type and concentration, and the type of diluent are evaluated. Variation of kinetic and molecular weight parameters in the homogeneous and heterogeneous polymerizations with reaction conditions are discussed.

On the Kinetics of Free Radical Polymerization of Macromonomers

Methacryloyloxyl polytetrahydrofuran (MA-PTHF) macromer was prepared by the coupling method which involved the reaction of sodium methacrylate with living PTHF. The MA-PTHF macromer obtained by this method was shown to be highly pure macromer by a UV spectrometric method, indicating one vinyl group per molecule. The radical polymerization of the macromer was performed to check the polymerizability of the macromer. At a relatively high concentration of the macromer, it was homopolymerized at a high conversion of ca. 90%. Furthermore, the macromer was quantitatively copolymerized with styrene to the copolymer. This quantitative conversion is consistent with the high purity of MA-PTHF macromer obtained.

Tetsuya Kuwabara

Papers

Preparation of methacryloyloxyl polytetrahydrofuran macromer