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JP-7855226-B2 - Living radical polymer and method for producing the same

JP7855226B2JP 7855226 B2JP7855226 B2JP 7855226B2JP-7855226-B2

Inventors

  • 高村 真澄

Assignees

  • 国立大学法人山形大学

Dates

Publication Date
20260508
Application Date
20220621

Claims (10)

  1. A composition comprising a living radical polymer having an organic compound moiety derived from a polymerization initiator in one end or main chain of the living radical polymer, and having a terminal functional group structure represented by the following formula (1), formula (2), or formula (3) in at least one of its ends, The purity of the living radical polymer is 70-100%. A composition containing a living radical polymer. (In formula (1), R1 is independently either a hydrogen atom or a fluorine atom, and n is an integer from 1 to 17.) (In formula (2), R 2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.) (In formula (3), R2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.)
  2. A composition comprising the living radical polymer according to claim 1, wherein the organic compound moiety is derived from a polymerization initiator containing iodine as a dormant.
  3. A composition comprising the living radical polymer according to claim 1, wherein the living radical polymer contains structural units derived from acrylate as the main structural units.
  4. A composition comprising the living radical polymer according to claim 1, wherein the molecular weight distribution (weight-average molecular weight / number-average molecular weight) of the living radical polymer is 1.0 to 1.5.
  5. A method for producing a composition containing a living radical polymer according to any one of claims 1 to 4, A polymerization step to form a precursor of a living radical polymer using a polymerization initiator containing an organic compound moiety and a dormant, and a radically polymerizable unsaturated monomer, A method for producing a composition containing a living radical polymer, comprising: an introduction step of reacting a functional group-containing radical generator represented by any of the following formulas (4) to (6) with the dormant terminal derived from the dormant of the precursor, thereby introducing a terminal functional group structure derived from the radical generator in place of the dormant terminal. (In equation (4), R1 is independently a hydrogen atom or a fluorine atom, and n is independently an integer from 1 to 17.) (In formula (5), R2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.) (In formula (6), R2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.)
  6. The method for producing a composition containing a living radical polymer according to claim 5, wherein the reaction temperature for producing the composition containing the living radical polymer in the introduction step is 70 to 130°C.
  7. A method for producing a composition containing a living radical polymer according to claim 5, wherein in the polymerization step, 0.1 to 50 moles of the polymerization initiator are used per 100 moles of the radical polymerizable unsaturated monomer.
  8. A method for producing a composition containing a living radical polymer according to claim 5, wherein in the introduction step, 0.5 to 30 moles of the radical generating agent are used per mole of the dormant terminal of the precursor.
  9. A method for producing a composition containing a living radical polymer according to claim 5, wherein in the introduction step, the radical generating agent is added dropwise to the reaction system.
  10. A method for producing a composition containing a living radical polymer according to claim 5, wherein the introduction step is carried out in the presence of a nonmetallic compound having an ionic bond with an iodide ion.

Description

This invention relates to living radical polymers having a specific terminal functional group structure, and to methods for producing the same. Living radical polymerization is a groundbreaking polymerization method that leverages the advantages of radical polymerization, such as its simplicity and versatility, while overcoming its drawback of heterogeneous molecular weight. Living radical polymerization is obtained by using a polymerization initiator composed of a dormant (which generates polymerization active ends in the presence of a catalyst) and an organic compound moiety, along with a radically polymerizable unsaturated monomer. The polymer (hereinafter referred to as the precursor) has its ends bonded to the organic compound moiety and dormant from the polymerization initiator, respectively. Therefore, by adding a new radically polymerizable monomer to the precursor and polymerizing it, copolymers with different components can be obtained (such as block copolymers with block-like bonding, graft copolymers with branch-like bonding, and star-shaped copolymers or ladder-shaped copolymers with star-like bonding). Since the primary structure of copolymers with such different bonding states significantly influences the chemical and physical properties of the polymer, living radical polymerization is an important technology both academically and industrially. However, the resulting precursor dormants contain sulfides, halogens, or transition metals, resulting in drawbacks such as odor, corrosiveness, toxicity, and discoloration, which significantly limit their application to various uses. Therefore, it is necessary to remove the resulting precursor dormants. On the other hand, by attaching functional groups to the precursor ends, it becomes possible to express new functions, for example, by segregating the functional groups near the surface of the thin film, reacting them with other polymers, or adsorbing or reacting them with the surface of organic or inorganic particles. There are two types of precursors with functional groups attached to their ends: (I) polymers in which the organic compound portion of a polymerization initiator containing functional groups is attached to the precursor end, and (II) polymers in which a functional group-containing compound is used to remove the dormant at the precursor end while simultaneously attaching a new functional group to the end. In polymer (I) described above, a dormant end is present at one end of the polymer, which is undesirable from a safety standpoint, such as toxicity, as mentioned earlier. For example, Patent Document 1 describes a living radical polymer in which hydrolyzable silyl groups are bonded via nitrogen and sulfur as the polymer described in (II) above. Non-Patent Document 1 describes a polymer in which hydroxyl groups, thiol groups, or alkoxysilyl groups are bonded to a precursor via nitrogen. However, the polymers obtained in these documents had the problem that the desired chemical structure could not be bonded due to degradation caused by side reactions. Japanese Patent Publication No. 2011-74325 Macromolecules, (USA), 2016, No. 49, pp. 9425-9940. The MALDI-TOFMS spectrum of the precursor is shown.The MALDI-TOFMS spectra of living radical polymers are shown. The spectra are based on Linear mode data, while the precise molecular weights of the peaks are based on Spiral mode data. Furthermore, all precise molecular weights listed in the spectra include the ionizing agent Na (precise mass = 22.99). The present invention will be described in detail below. [1. Living radical polymers] (1-1. Structure of living radical polymers) The living radical polymer of the present invention has a specific functional group at at least one terminal. That is, in the radical polymer of the present invention, one terminal or the center (in the main chain) contains an organic compound moiety derived from a polymerization initiator, and at least one of the terminals contains a specific functional group represented by the following formulas (1), (2), or (3). (In formula (1), R1 is independently either a hydrogen atom or a fluorine atom, and n is an integer from 1 to 17.) (In formula (2), R2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.) (In formula (3), R2 is independently a hydrogen atom, an alkyl group, a fluorine atom, or a perfluoroalkyl group.) The structure of living radical polymers having the aforementioned functional groups differs primarily depending on the polymerization initiator, for example, the number of dormants in a single molecule of the polymerization initiator. For instance, in the case of a living radical polymer obtained from a monofunctional polymerization initiator having one dormant per molecule, one end of the polymer's main chain is bonded to an organic compound fragment of the polymerization initiator, while the other end is bonded to a compound with a specific functional group. On the othe