JP4768997B2 - Compound - Google Patents

Description

  The present invention relates to a compound, a polymerization method, a polymer, and a block polymer, and relates to a compound, a polymerization method, a polymer, and a block polymer related to a polymerization initiator used in, for example, atom transfer type living radical polymerization.

Conventionally, the atom transfer type living radical polymerization method (Atomic Transfer Radical Porimelzation (ATRP) method) is known as a method for easily obtaining a narrow dispersion polymer by using a compound having a chlorine atom or a bromine atom in the molecule. (For example, see Non-Patent Documents 1 to 7).
Jin-Shan Wang: J. Am. Chem. Soc., 117, 5614 (1995) Jin-Shan Wang: Macromolecules, 28,7572 (1995) Virgil Percec: Macromolecules, 28, 7970 (1995) Mitsuru Kato: Macromolecules, 28, 1721 (1995) Jianhui Xia: Macromolecules, 32, 3531 (1999) Dong-Qi Qin: Macromolecules, 33, 6987 (2000) Shenmin Zhu: Macromolecules, 33, 8233 (2000)

  However, as a method for measuring the molecular weight of a polymer, using a nuclear magnetic resonance apparatus (NMR), it is possible to calculate based on the intensity ratio of the absorption spectrum of protons derived from the absorption derived from the initiator at the end of the polymer. Are known. However, in the conventionally known initiator, the difference between the chemical shift value derived from the initiator and the chemical shift value of the other polymer is small, so if the degree of polymerization increases, it will be absorbed in the absorption derived from the polymer. There was a problem in that it was difficult to accurately calculate the polymer molecular weight.

  The present invention has been made in view of the above-described circumstances, and provides an initiator having a chemical shift value greatly different from a proton-absorbing chemical shift value derived from a polymer, as measured using a nuclear magnetic resonance apparatus, An object is to provide a compound, a polymerization method, a polymer, and a block polymer that can easily calculate the molecular weight of the polymer.

In order to solve the above-mentioned problems, the invention described in claim 1 is characterized by the main feature of a compound represented by the following general formula (1).
(Wherein R _{1 to} R ₃ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group, X represents a halogen atom, and n represents an integer.)

  The invention according to claim 2 is characterized by a polymerization method using the compound according to claim 1 as an initiator.

The invention according to claim 3 is mainly characterized by a polymer containing the following residues derived from the compound according to claim 1.
(Wherein R _{1 to} R ₃ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, and n represents an integer.)

The invention described in claim 4 is the polymer described in claim 3, characterized in that it includes a structure represented by the following general formula (2) as a repeating unit.
(In the formula, R ₄ and R ₅ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)

  Further, the invention according to claim 5 is characterized mainly by a polymerization method using the polymer according to claim 3 or 4 as a macroinitiator.

  The invention described in claim 6 is mainly characterized by a block polymer obtained by the polymerization method described in claim 5.

As a result of the verification, the structure has a benzene ring in the molecule, and by not substituting substituents at the 2, 3, 5, and 6 positions of the benzene ring, proton absorption derived from the benzene ring and proton absorption derived from the polymer It became clear that can be observed independently.
In addition, it has been clarified that the polymer synthesized using the compound represented by the above general formula (1) as a starting material can correctly calculate the molecular weight.

According to the present invention, in the above general formula (1), R _{1 to} R ₃ each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group, X represents a halogen atom, and n represents an integer. The compound represented by the general formula (1) to be represented can provide a new initiator for the purpose of molecular weight evaluation.

  Further, it is possible to provide a method for synthesizing a polymer in a simple environment without synthesizing with an ampoule or the like sealed under high vacuum, and it is possible to provide a polymer with an accurate molecular weight evaluated.

  Furthermore, it is possible to provide a method for synthesizing a block polymer using the compound according to claim 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present embodiment relates to a polymerization initiator, a polymerization method using the same, and a polymer, and particularly relates to an initiator used in atom transfer type living radical polymerization.
The living radical polymerization initiator of this embodiment is composed of a compound represented by the following general formula (1).
(Wherein R _{1 to} R ₃ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group, X represents a halogen atom, and n represents an integer.)

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, and n-nonyl group. Primary alkyl group such as n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, 2-methylhexyl group 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5 -Methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, isopropyl group, sec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1- Ethylbutyl group, 1,3-dimethylbuty Group, 1,2-dimethylbutyl group, 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2-methylpropyl group, 1 -Ethyl-2-methylbutyl group, 1-ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, Secondary alkyl groups such as 1-isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group , Neopentyl group, tert-butyl group, tert-hexyl group, tert-amyl group, tertiary alkyl group such as tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butyl Cyclohexyl 4- (2-ethylhexyl) cyclohexyl group, bornyl group, a cycloalkyl group such as isobornyl group (adamantane group).

  Further, these primary and secondary alkyl groups may be substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, and the like. . Further, it may be substituted so as to have a structure in which the above-described alkyl group is added through atoms such as oxygen, sulfur, and nitrogen.

Examples of the alkyl group substituted to be added via oxygen include methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, butoxyethyl group, ethoxyethoxyethyl group, phenoxyethyl group, methoxy Examples of the alkyl group in which propyl group, ethoxypropyl group, piperidino group, morpholino group, etc. are substituted via sulfur include methylthioethyl group, ethylthioethyl group, ethylthiopropyl group, phenylthioethyl group, etc. Examples of the alkyl group substituted via a dimethylaminoethyl group, diethylaminoethyl group, diethylaminopropyl group, and the like. Specific examples of the heterocyclic residue include indolyl group, furyl group, thienyl group, pyridyl group, piperidyl group, quinolyl group, isoquinolyl group, piperidino group, morpholino group, pyrrolyl group and the like.
Specific examples of the halogen atom include chlorine, bromine, iodine and the like.

Moreover, it is preferable that the polymer containing the residue derived from the compound represented by the general formula (1) described above includes a structure represented by the following general formula (2) as a repeating unit.
(In the formula, R ₄ and R ₅ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. Specific examples of the substituent may be the same as those described above.)

The initiator represented by the general formula (1) is characterized by having a benzene ring and having substituents only at the 1-position and 4-position thereof. In other words, the hydrogen atom is attached to the 2, 3, 5, 6 position of the benzene ring.
A carbon atom is substituted at the 1-position (4-position) of benzene, and an oxygen atom is substituted at the 4-position (1-position). By taking such a structure, a characteristic absorption spectrum can be shown in proton NMR measurement. Electromagnetic absorption of hydrogen derived from the benzene ring is only two types of doublet absorption bands. Since only the 1st and 4th positions are substituted, the 2nd and 6th positions, the 3rd and 5th positions are degenerate, and are observed as characteristic doublets in the vicinity of 7.1 ppm and 6.8 ppm. .

  FIG. 1 is an enlarged view of a proton NMR spectrum (6.5-7.3 ppm) of the compound example represented by the general formula (1). 1 to 8 below, the horizontal axis represents the chemical shift value (δ value) and the vertical axis represents the absorption intensity.

In general, the polymerization procedure by the ATRP method is roughly as follows.
Put the necessary raw materials in a container such as an ampoule and put it into liquid nitrogen to solidify the contents. Next, it is sufficiently deaerated with a vacuum pump or the like and sealed with a cock or the like, then the contents are dissolved and the dissolved gas in the liquid is discharged into the gas phase. Next, the inside of the container is replaced with a gas not containing oxygen such as nitrogen. After repeating this series of operations several times, the inside of the container is again sucked with a vacuum pump or the like to make a high vacuum state, and then the container is completely sealed. At this time, the mouth of the glass container is generally burned off and sealed with a burner or the like. Thereafter, the reaction is started by heating to the required temperature.

Many of the initiators used in the ATRP method have a low boiling point. Therefore, when degassing, the initiator is prevented from evaporating by, for example, putting it into liquid nitrogen so that the stoichiometric ratio in the reaction system does not change. It is necessary to devise. On the other hand, since the initiator represented by the general formula 1 has a high boiling point, it is not necessary to worry about evaporation of the initiator due to degassing.
In polymerization using an initiator represented by the general formula 1, raw materials are placed in a reaction vessel, deoxygenated from the raw materials and the inside of the vessel at room temperature, and then replaced with an inert gas that does not affect radicals such as argon and nitrogen. Under the necessary heating, a polymer having a residue derived from the general formula (1) shown below as the start terminal can be obtained.
(Wherein R _{1 to} R ₃ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, and n represents an integer.)

  When the electromagnetic wave absorption of the polymer thus obtained is observed by proton NMR, the absorption band derived from the initiator can be observed at a position different from the absorption band derived from the polymer, thus making it easy to determine the molecular weight of the polymer. be able to.

  The initiator represented by the general formula (1) is particularly advantageous in a polymer having a repeating unit represented by the general formula (2). Many of the initiators used in the synthesis of these are ester compounds having a low molecular weight. The molecular weight of a polymer synthesized using such an initiator is determined by the absorption band derived from methyl, methylene or methine groups bonded to oxygen in the ester group of the initiator, and the methyl bonded to oxygen in the ester group of the polymer. It is determined by the ratio of the absorption area to the absorption band derived from the methylene or methine group.

  As the molecular weight of the polymer increases, in the proton NMR spectrum, the absorption band derived from the initiator is buried in the absorption band derived from the polymer and cannot be determined. In addition, in the polymer of hydroxy-methyl-methacrylate (HEMA), the absorption band derived from the initiator completely overlaps the absorption band derived from the polymer, so that the molecular weight cannot be determined. As Comparative Example 1, the NMR spectrum of a methyl-methacrylate (MMA) polymer using 2-bromo-2-methylpropionic acid ethyl ester as an initiator is shown in FIG. 2, and as Comparative Example 2, MMA using the same initiator. The spectrum of the copolymer of HEMA and HEMA is shown in FIG.

  In Comparative Example 1 shown in FIG. 2, the absorption band of the methylene group derived from the initiator is observed at about 4.1 ppm. Since the absorption band of the methylene group derived from the initiator is close to the absorption band of the methyl group derived from MMA, the absorption band of the methylene group derived from the initiator becomes the absorption band of the methyl group derived from the polymer as the molecular weight of the polymer increases. It will be buried in. Moreover, in the polymer in which HEMA exists as in Comparative Example 2, as shown in FIG. 3, the absorption band of the methylene group derived from the initiator is observed at around 4.1 ppm, and the two types of methylene groups derived from HEMA Since there is an absorption band and it overlaps with the absorption band of the methylene group derived from the initiator, it cannot be observed.

On the other hand, FIG. 4 shows a proton NMR spectrum of a polymer of MMA and HEMA obtained by polymerizing the compound represented by the general formula (1) described above as an initiator as the present embodiment. Absorption bands of the initiator-derived benzene ring are observed as characteristic doublets in the vicinity of 7.1 ppm and 6.8 ppm.
The polymer synthesized from the initiator represented by the general formula (1) is suitable for use as a macroinitiator because its molecular weight can be accurately determined. By using a macroinitiator having a determined molecular weight, the required amount of catalyst can be accurately introduced, which is an excellent method for synthesizing a block polymer.

[Synthesis of Compound Example 1]
A reaction vessel was charged with 10.0 g of 4-methoxyphenethyl alcohol, 100 ml of dehydrated tetrahydrofuran (THF), and 8.0 g of triethylamine, and cooled to 5 ° C. or lower in an ice bath. To this solution, 16.7 g of 2-bromo-2-methylpropionic acid bromide was added dropwise and stirring was continued for 5 hours. The precipitated triethylamine hydrochloride was collected by filtration and concentrated, and the concentrated oily substance was discharged into 300 ml of water. After neutralization, this was extracted with toluene, and the toluene layer was dried over anhydrous sodium sulfate and concentrated. After concentration, distillation was performed to obtain 19.1 g of the desired product.
The ¹ H and ¹³ C NMR spectra of the obtained compound are shown in FIGS. 5 and 6, respectively.

The analysis result of FIG. 5 is shown below.

The analysis result of FIG. 6 is shown below.

[Synthesis of Compound Example 2]
Into the reaction vessel, 15.3 g of 4-methoxyphenethyl alcohol, 75 ml of dehydrated THF, and 13.3 g of triethylamine were charged and cooled to 5 ° C. or lower in an ice bath. To this solution, 15.4 g of 2-chloropropionic acid chloride was added dropwise and stirring was continued for 5 hours. The precipitated triethylamine hydrochloride was collected by filtration and concentrated, and the concentrated oily substance was discharged into 300 ml of water. After neutralization, this was extracted with toluene, the toluene layer was washed with water, dried over anhydrous sodium sulfate and concentrated. The concentrate was produced by column chromatography (silica gel / toluene) to obtain 22.6 g of the desired product.
The ¹ H and ¹³ C NMR spectra of the obtained compound are shown in FIGS. 7 and 8, respectively.

The analysis result of FIG. 7 is shown below.

The analysis result of FIG. 8 is shown below.

[Synthesis of Polymerization Example 1]
In a reaction vessel equipped with a cooling tube and a balloon filled with argon gas, 4.00 g of MMA, 1.30 g of HEMA and 10 ml of methyl ethyl ketone were added. Next, 0.0461 g of 1,1,4,7,10,10-hexamethyltriethylenetetramine and 0.0099 g of cuprous chloride were added and stirred until the copper salt was dissolved. 0.0301 g of Compound Example 1 was added to this solution, the inside of the reaction system was deaerated with a vacuum pump, and the inside of the system was replaced with argon gas. After repeating this operation three times, polymerization was carried out at 40 ° C. for 5 hours under an atmospheric pressure argon gas atmosphere. After completion of the polymerization, the reaction solution was discharged into methanol-water (1: 3) to obtain a precipitated MMA-HEMA random copolymer.
Mn (NMR) = 45,000
Mn (GPC) = 37,000
Mw (GPC) = 46,000
Mw / Mn (GPC) = 1.24 GPC: MMA conversion

[Synthesis of Polymerization Example 2]
1.60 g of Polymerization Example 1, 3.00 g of styrene, and 5 ml of DMF were added to a reaction vessel equipped with a condenser tube and a balloon filled with argon gas. Next, 0.0165 g of tri (2-dimethylaminoethyl) amine and 0.0035 g of cuprous chloride were added and stirred until the copper salt was dissolved. After dissolving the copper salt, the inside of the reaction system was deaerated with a vacuum pump, and the inside of the system was replaced with argon gas. After repeating this operation three times, polymerization was carried out at 120 ° C. for 10 hours under an atmospheric pressure argon gas atmosphere. After completion of the polymerization, the reaction solution was discharged into methanol, and a precipitated (PMMA-PHEMA) -b-polystyrene block copolymer was obtained.
Mn (NMR) = 69,000
Mn (GPC) = 44,000
Mw (GPC) = 66,000
Mw / Mn (GPC) = 1.50 GPC: MMA conversion

[Synthesis of Polymerization Example 3]
Into a reaction vessel equipped with a cooling tube and a balloon filled with argon gas, 5.00 g of 4-vinylpyridine and 10 ml of DMF were added. Next, 0.0276 g of tri (2-dimethylaminoethyl) amine and 0.0099 g of cuprous chloride were added and stirred until the copper salt was dissolved. 0.0243 g of Compound Example 2 was added to this solution, and the inside of the reaction system was deaerated with a vacuum pump, and then the inside of the system was replaced with argon gas. After repeating this operation three times, polymerization was carried out at 50 ° C. for 5 hours under an atmospheric pressure argon gas atmosphere. After completion of the polymerization, the reaction solution was discharged into water to obtain a precipitated 4-vinylpyridine polymer.
Mn (NMR) = 39,000
Mn (GPC) = 43,000
Mw (GPC) = 55,000
Mw / Mn (GPC) = 1.28 GPC: Styrene conversion

[Synthesis of Polymerization Example 4]
1.50 g of Polymerization Example 3, 3.00 g of MMA, and 5 ml of DMF were added to a reaction vessel equipped with a condenser tube and a balloon filled with argon gas. Next, 0.0115 g of tri (2-dimethylaminoethyl) amine and 0.0038 g of cuprous chloride were added and stirred until the copper salt was dissolved. After dissolving the copper salt, the inside of the reaction system was deaerated with a vacuum pump, and the inside of the system was replaced with argon gas. After repeating this operation three times, polymerization was carried out at 40 ° C. for 4 hours under an atmospheric pressure argon gas atmosphere. After completion of the polymerization, the reaction solution was discharged into methanol-water (1: 2) to obtain a precipitated poly-4-vinylpyridine-b-PMMA block copolymer.
Mn (NMR) = 82,000
Mn (GPC) = 86,000
Mw (GPC) = 114,000
Mw / Mn (GPC) = 1.33 GPC: Styrene conversion

[Examples of compounds]
The compound example general formula as embodiment of this invention is shown.

Illustrative compounds for the above general formulas are shown below.
Example 1 described above is a synthesis example of a compound corresponding to “Compound Example 1” in Table 1, and FIGS. 5 and 6 correspond to data for measuring the compound.
Example 2 described above is a synthesis example of a compound corresponding to “Compound Example 2” in Table 1, and FIGS. 7 and 8 correspond to data for measuring the compound.

It is a NMR spectrum enlarged view of the compound example shown by General formula (1) in embodiment of this invention. 2 is an NMR spectrum diagram of Comparative Example 1. FIG. 4 is an NMR spectrum diagram of Comparative Example 2. FIG. It is a NMR spectrum figure of the polymer example polymerized using the compound shown by the said General formula (1) as an initiator. 1 is a ¹ H-NMR spectrum diagram in Example 1 of the present invention. FIG. It is a ¹³ C-NMR spectrum diagram in Example 1 of the present invention. It is a ¹ H-NMR spectrum diagram in Example 2 of the present invention. It is a ¹³ C-NMR spectrum diagram in Example 2 of the present invention.

Claims (1)

A compound represented by the following general formula (1):
(In the formula, R ₁ and R ₃ represent a methyl group, R ₂ represents a hydrogen atom or a methyl group, X represents bromine or chlorine, and n = 2. )