JP2010155880A - Stimuli-responsive crosslinked polymer and production method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stimuli-responsive crosslinked polymer which can be simply produced; to provide a novel stimuli-responsive crosslinked polymer; and to provide a method for producing them. <P>SOLUTION: A polymer (A) with two or more annular parts and a straight-chain molecule (B) with a block group at one end and a polymerizable functional group at the other end are mixed to produce a crosslinked polymer precursor (C) with an inclusion complex in at least part thereof, after which the straight-chain polymer (B) and a stimuli-responsive compound (D) are copolymerized by means of the polymerizable functional group in the straight-chain molecule (B), thereby yielding a stimuli-responsive crosslinked polymer (E) that contains a rotaxane structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stimulus-responsive polymer crosslinked body and a method for producing the same.

  Patent Document 1 discloses a crosslinked polymer (polymer gel) having a rotaxane structure in which a polydrotaxane is crosslinked using cyclodextrin as a cyclic molecule and polyethylene glycol as a linear molecule included in the cyclic molecule. ing.

Unlike conventional physical gels or chemical gels, this polymer gel is composed of mechanical bonds (interlock structure) that do not use both non-covalent bonds and covalent bonds, and cyclic molecules are linear molecules. Because it can move freely, it can exhibit unprecedented flexibility.
Japanese Patent No. 3475252

  By the way, a stimulus-responsive substance whose physical properties change in response to a stimulus such as temperature is known. In order to produce a stimulus-responsive gel in which stimulus-responsiveness is imparted to the above polymer gel, a stimulus-responsive polymer is used as a linear molecule to be included, or a polyrotaxane is synthesized and then linear It is necessary to introduce a stimulus-responsive compound into the molecule.

  However, in any of the above methods, a pseudo-polyrotaxane is synthesized and isolated, the pseudo-polyrotaxane is dissolved again in another solvent, and then the end is capped with a capping agent to obtain a polyrotaxane, which is again isolated and purified. In addition, it is necessary to further crosslink the cyclodextrin part of the polyrotaxane by acting a crosslinking agent. When industrialization is considered, such a multistage reaction is very disadvantageous from the viewpoint of production cost, and the yield of each stage is never high.

  Further, in the former method, it is difficult to penetrate a stimulus-responsive polymer through a cyclic molecule, and in the latter method, it is difficult to introduce a stimulus-responsive compound into a linear molecule after polyrotaxane synthesis. There is no simple method for producing a stimulus-responsive gel.

  The present invention has been made in view of such circumstances, and provides a stimulus-responsive polymer crosslinked body that can be easily produced, a novel stimulus-responsive polymer crosslinked body, and a method for producing the same. Objective.

  In order to achieve the above object, first, the present invention comprises a polymer having two or more cyclic moieties, a linear molecule having a blocking group at one end and a polymerizable functional group at the other end. To form an inclusion complex for all or part of the mixture, and then to copolymerize the linear molecule and the stimulus-responsive compound via the polymerizable functional group of the linear molecule. Provided is a method for producing a characteristic crosslinked stimulus-responsive polymer (Invention 1). Note that the stimulus-responsive compound used for copolymerization with the linear molecule is a monomer.

  According to the said invention (invention 1), the stimulus-responsive polymer crosslinked body which has an interlock structure can be simply manufactured, without passing through the synthesis | combination and isolation of a pseudo rotaxane.

  Second, the present invention provides a stimulus-responsive polymer crosslinked product having an interlock structure and containing a stimulus-responsive compound or a residue thereof in the skeleton (Invention 2).

  In the said invention (invention 2), you may have the site | part bridge | crosslinked by the compound which has an interlock structure (invention 3).

  In the said invention (invention 2 and 3), it is preferable that the said interlock structure is a rotaxane structure (invention 4). However, the present invention is not limited to this, and the interlock structure may be a catenane structure, for example.

  Third, the present invention relates to a polymer having two or more cyclic moieties, and a linear chain capable of forming an inclusion complex with the polymer having a blocking group at one end and a polymerizable functional group at the other end. It is obtained by copolymerizing the linear molecule and the stimulus-responsive compound via the polymerizable functional group of the linear molecule of the polymer crosslinking precursor obtained by mixing the linear molecules. A characteristic stimulus-responsive polymer crosslinked product is provided (Invention 5).

  The cross-linked stimulus-responsive polymer according to the invention (Invention 5) includes a linear molecule of a polymer cross-linking precursor and a stimuli-responsive compound via a polymerizable functional group having the terminal end of the linear molecule. It can be produced simply by copolymerization. This stimulus-responsive polymer crosslinked product is excellent in flexibility, and a plastic material formed using the stimulus-responsive polymer crosslinked product is excellent in stress relaxation property and the like. Moreover, this stimulus-responsive polymer cross-linked product is characterized by exhibiting a larger swelling / contraction behavior in response to the stimulus and having a significantly faster contraction rate than a stimulus-responsive polymer cross-linked product prepared by conventional cross-linking.

  Fourthly, in the present invention, at least one side chain of the first polymer having a blocking group at the end of the side chain penetrates like a skewer into the opening of the cyclic part in the polymer having two or more cyclic parts. In addition, at least one side chain of the second polymer having a blocking group at the end of the side chain penetrated in a skewered manner into the opening of at least one of the remaining cyclic portions of the polymer having the same cyclic portion. A stimuli-responsive compound or a compound thereof at least in one portion of the first polymer, the second polymer, or the portion that binds the first polymer and the second polymer. Provided is a stimulus-responsive polymer crosslinked product containing a residue (Invention 6).

  The stimulus-responsive polymer crosslinked product according to the above invention (Invention 6) is excellent in flexibility because the cyclic portion of the polymer can move on the side chain of the polymer, and therefore, the stimulus-responsive polymer crosslinked product is used. The plastic material thus formed is excellent in stress relaxation properties. Moreover, this stimulus-responsive polymer cross-linked product is characterized by exhibiting a larger swelling / contraction behavior in response to the stimulus and having a significantly faster contraction rate than a stimulus-responsive polymer cross-linked product prepared by conventional cross-linking.

  In the above invention (Invention 6), the stimulus-responsive compound as a polymer may constitute the main chain of the first polymer and / or the second polymer (Invention 7).

  In the above inventions (Inventions 5 to 7), the cyclic portion of the polymer is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, or cyclic polyether, cyclic polyester, cyclic It is preferably at least one selected from the group consisting of polyetheramines and cyclic polyamines (Invention 8).

  In the said invention (invention 2-8), it is preferable that the said stimulus responsive compound is N-isopropylacrylamide or its polymer (invention 9).

  The stimuli-responsive polymer crosslinked product obtained by using the stimuli-responsive polymer crosslinked product according to the invention (Invention 8) has a surface state that significantly changes from transparent or translucent to white by heating. Changes from hydrophilic to hydrophobic.

  ADVANTAGE OF THE INVENTION According to this invention, the stimulus responsive polymeric crosslinked body which has an interlock structure can be manufactured simply and efficiently. In addition, according to the present invention, a novel stimulus-responsive polymer crosslinked body having an interlock structure can be obtained. The obtained stimulus-responsive polymer crosslinked product is excellent in flexibility, and a plastic material formed using the stimulus-responsive polymer crosslinked product is excellent in stress relaxation property and the like. Furthermore, the stimulus-responsive polymer crosslinked product has characteristics of exhibiting a larger swelling / contraction behavior in response to the stimulus and a significantly faster contraction rate than a stimulus-responsive polymer crosslinked product prepared by conventional crosslinking.

Hereinafter, embodiments of the present invention will be described.
The stimuli-responsive polymer crosslinked product according to one embodiment of the present invention can be produced by the method schematically shown in FIG.

  First, a polymer having two or more cyclic moieties (hereinafter referred to as “polymer (A)”) and a linear molecule having a blocking group at one end and a polymerizable functional group at the other end (hereinafter referred to as “polymer (A)”) (Referred to as “linear molecule (B)”) (see FIG. 1).

  The cyclic portion of the polymer (A) can include the linear molecule (B) and can move on the linear molecule (B) in that state. In the present specification, “cyclic” of “cyclic portion” means substantially “cyclic”, and is cyclic if it can move while being included on the linear molecule (B). The portion may not be completely closed, and may be, for example, a helical structure. Further, the polymer (A) of the present invention is a multimer having a cyclic molecule having a relatively large molecular weight as a constituent part as described later, and its own molecular weight becomes enormous even if the number of repetitions is small. The polymer (A) of the present invention is a name used for this purpose for convenience, and includes those having a repeating number of oligomer regions of about 2 to 10 mer.

  The cyclic moiety is preferably a cyclodextrin such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, or a cyclic molecule such as cyclic polyether, cyclic polyester, cyclic polyetheramine, and cyclic polyamine. Two or more parts may be mixed in the polymer (A) or in the polymer cross-linking precursor (C) or the stimulus-responsive polymer cross-linked product (E).

  When the cyclic moiety is a cyclodextrin, a polymer chain and / or a substituent that can improve the solubility of the polymer (A) in the linear molecule (B) is introduced into the hydroxyl group of the cyclodextrin. It may be. Examples of such a polymer chain include an oxyethylene chain, an alkyl chain, and an acrylate chain. On the other hand, examples of the substituent include an acetyl group, an alkyl group, a trityl group, a tosyl group, a trimethylsilane group, and a phenyl group.

  Specific examples of the cyclic moiety other than cyclodextrin include crown ether or a derivative thereof, calixarene or a derivative thereof, cyclophane or a derivative thereof, cryptand or a derivative thereof.

  As the cyclic portion, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and crown ether are preferable because linear molecules are easy to penetrate in a skewered manner. Α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin are particularly preferable because they form a complex.

  The number of cyclic portions in the polymer (A) is 2 or more, preferably 3 to 50, particularly preferably 4 to 10. By having two or more cyclic portions, it is possible to include a plurality of linear molecules (B), and by polymerizing the linear molecules (B), a plurality of polymers (A) can be mutually attached. Connected to form a cross-linked structure. Three or more cyclic portions are more preferable because the cross-linked structure becomes dense, and the strength can be improved without inhibiting the stress relaxation property of the resulting stimulus-responsive polymer cross-linked product (E).

  The structure of the polymer (A) is preferably a structure in which two or more cyclic parts are connected by a connecting part. The molecule of the linking moiety (linking moiety molecule) is preferably a molecule that does not form or is difficult to make an inclusion complex with the cyclic moiety. By using such a linking moiety molecule, when synthesizing the polymer (A), the cyclic moiety can be linked while leaving the opening of the cyclic moiety as an opening.

  As the linking moiety molecule, a molecule that does not form an inclusion complex with the cyclic moiety is preferably used. Such a molecule may be linear or branched, but preferably has a side chain that is bulky to some extent. For example, when the cyclic moiety is α-cyclodextrin, it preferably has a side chain that is bulkier than a methyl group. That is, from the viewpoint of not forming an inclusion complex with the cyclic moiety, preferred linking moiety molecules include polypropylene glycol, polyacrylic acid ester, polydimethylsiloxane, polyisoprene, and the like, among which polypropylene glycol is particularly preferable.

  The number average molecular weight (Mn) of one linking moiety molecule is preferably 100 to 100,000, particularly preferably 500 to 10,000. If the number average molecular weight of the linking moiety molecule is less than 100, the opening of the cyclic part of the polymer (A) is too close to take a crosslinked structure, and the effect based on the interlock structure may not be sufficiently exhibited. If it exceeds 100,000, the compatibility with the linear molecule (B) and the like is deteriorated, and it may be difficult to form a crosslinked structure.

  The mass average molecular weight (Mw) of the polymer (A) depends on the kind of the cyclic portion, but is usually preferably 1,000 to 1,000,000, particularly 3,000 to 100,000. It is preferable. When the weight average molecular weight of the polymer (A) is less than 1,000, the number of cyclic portions is often less than 2, and there is a possibility that an interlock structure cannot be formed. Since the parts are very close to each other, the effect based on the interlock structure may not be sufficiently exhibited. On the other hand, when the mass average molecular weight of the polymer (A) exceeds 1,000,000, the compatibility with the linear molecule (B) or the like may be deteriorated and it may be difficult to form a crosslinked structure.

  The polymer (A) can be synthesized by a conventional method. For example, reacting a molecule having a functional group (cyclic molecule) constituting a cyclic moiety with a raw material compound constituting a linking moiety molecule having a reactive group capable of reacting with the functional group of the cyclic molecule at the terminal. Thus, the polymer (A) is obtained. Specifically, when synthesizing a polymer (A) in which the cyclic portion is α-cyclodextrin and the linking portion molecule is polypropylene glycol, α-cyclodextrin and polypropylene glycol having a reactive group at the terminal are mixed. Then, if desired, a catalyst is added and both are reacted to obtain the polymer (A).

  As the functional group of the cyclic molecule bonded to the linking moiety molecule, for example, a hydroxyl group, a carboxyl group, an amino group, a thiol group and the like are preferable, and as the reactive group at the terminal of the linking molecule, for example, an isocyanate group, an epoxy group, An aziridine group and the like are preferable. Examples of the raw material compound constituting the linking partial molecule include isocyanate compounds such as xylylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexane. Epoxy compounds such as diol glycidyl ether and those having an aziridine compound such as N, N-hexamethylene-1,6-bis (1-aziridinecarboxyamide) at the terminal can be used.

  The linear molecule (B) is a linear molecule or substance that is included in the cyclic portion of the polymer (A) and can be integrated by a mechanical bond rather than a chemical bond such as a covalent bond. And having a blocking group at one end and a polymerizable functional group at the other end. In the present specification, “linear” of “linear molecule” means substantially “linear”. That is, as long as the cyclic part of the polymer (A) can move on the linear molecule (B), the linear molecule (B) may have a branched chain.

  Examples of the part (main body part) excluding the blocking group and the polymerizable functional group corresponding to both ends of the linear molecule (B) include, for example, polyethylene glycol, polypropylene glycol, polyisoprene, polyisobutylene, polybutadiene, polytetrahydrofuran, Polyacrylic acid ester, polydimethylsiloxane, polyethylene, polypropylene and the like are preferable, and the linear molecule (B) having these main body portions is a polymer crosslinking precursor (C) or a stimulus-responsive polymer crosslinked material (E). Two or more of them may be mixed.

  The number average molecular weight (Mn) of the main body portion of the linear molecule (B) is preferably 100 to 300,000, particularly preferably 200 to 200,000, and more preferably 300 to 100,000. Preferably there is. When the number average molecular weight is less than 100, the amount of movement of the cyclic portion on the linear molecule (B) becomes small, and the resulting stimulus-responsive polymer crosslinked product (E) cannot be sufficiently flexible. There is a fear. Moreover, when a number average molecular weight exceeds 300,000, there exists a possibility that the solubility to a solvent may worsen.

  The blocking group is not particularly limited as long as the cyclic portion of the polymer (A) that includes the linear molecule (B) does not leave and can maintain the form of the inclusion complex. Examples of such groups include bulky groups and ionic groups.

  As the blocking group, for example, dialkylphenyl groups, dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes, anthracenes and the like are preferable. Or 2 or more types may be mixed in the polymer crosslinked body. As a capping agent that forms a blocking group by binding to one end of the linear molecule (B), for example, dimethylphenyl isocyanate, tritylphenyl isocyanate, 2,4-dinitrofluorobenzene, adamantaneamine and the like are preferably used. .

  The polymerizable functional group is not particularly limited as long as it can copolymerize the linear molecule (B) and a stimulus-responsive compound (D) described later via the polymerizable functional group. As such a polymerizable functional group, for example, (meth) acryloyl group, vinyl group, epoxy group, acetylene group, oxetanyl group and the like are preferable.

  The linear molecule (B) can be synthesized by a conventional method. For example, a linear molecule having a polymerizable functional group at one end, or a linear molecule having a different polymerizable functional group at both ends, and a capping agent for a blocking group are reacted, and one end is A linear molecule (B) can be obtained by leaving the above-mentioned polymerizable functional group and adding a blocking group to the other end.

  As an example, a linear molecule having a hydroxyl group at one end and a (meth) acryloyl group at the other end and a dialkylphenyl group having an isocyanate group are mixed, and if desired, a catalyst is added and both are reacted. Thus, a linear molecule (B) having a dialkylphenyl group as a blocking group at one end and a (meth) acryloyl group as a polymerizable functional group at the other end is obtained.

  When the polymer (A) and the linear molecule (B) described above are prepared, the polymer (A) and the linear molecule (B) are mixed to form an inclusion complex for all or part of the polymer (A) and the linear molecule (B). A polymer crosslinking precursor (C) is produced. That is, one opening portion of the annular portion of the polymer (A) is inserted in a skewered manner with the linear molecule (B), and at least one of the remaining openings of the annular portion of the polymer (A) is inserted. Polymeric cross-linking precursor having a structure in which two or more linear molecules (B) are included in a plurality of cyclic parts of the same polymer (A), penetrating with another linear molecule (B) (C) is manufactured (see FIG. 1).

  The polymer cross-linking precursor (C) is characterized in that it has a structure in which the above-mentioned inclusion complex is formed, but all the openings of the cyclic part of the polymer (A) are in such a state. You don't need to be. That is, in the polymer (A) as a mixture, a structure in which the linear molecule (B) is penetrated in only one of the openings of the cyclic part, and further, the cyclic part of the polymer (A) May include a portion having a structure in which the linear molecule (B) is not penetrated in a skewered manner at all, or the linear molecule as a mixture not included in the polymer (A) (B) may be included.

  The polymer crosslinking precursor (C) as described above is prepared by mixing the polymer (A) and the linear molecule (B) in a solvent, for example, water, aqueous sodium hydroxide, dimethylformamide (DMF) and water. In a mixed solution of methanol and water or the like (for example, by adding the linear molecule (B) to the polymer (A) solution) and stirring the solution. it can. The fact that the polymer crosslinking precursor (C) has been obtained can be judged by an increase in the viscosity of the solution.

  There is no restriction | limiting in particular about the stirring method, It can stir by methods, such as a mechanical stirring process and an ultrasonic treatment, at normal temperature or the temperature controlled appropriately, It is preferable to specifically stir by ultrasonic treatment. The stirring time is preferably performed under conditions of several minutes to 1 hour. Although there is no restriction | limiting in particular about the irradiation conditions of an ultrasonic wave, It is preferable to carry out with a frequency of 20-40 kHz.

  When the polymer cross-linking precursor (C) is produced as described above, the linear molecule is introduced via the polymerizable functional group of the linear molecule (B) included in the cyclic portion of the polymer (A). (B) and a stimulus-responsive compound (D) are copolymerized to obtain a stimulus-responsive polymer crosslinked product (E) (see FIG. 1). This stimulus-responsive polymer crosslinked product (E) contains a rotaxane structure as an interlock structure.

  The stimulus-responsive compound (D) copolymerized with the linear molecule (B) can be copolymerized with the linear molecule (B) via the polymerizable functional group of the linear molecule (B), and It is a monomer that exhibits stimulus responsiveness when a polymer gel is formed using the stimulus responsive compound (D). Examples of the polymerizable functional group include a polymerizable group such as a carbon-carbon double bond. The molecular weight of the monomer is not particularly limited.

  Here, details of the stimulus-responsive compound (D) will be described. Examples of stimuli-responsive stimuli include changes in temperature; application of light, magnetic field, current or electric field; changes in pH, ion concentration or solvent composition; adsorption / desorption of chemical substances, and the like. The response behavior includes volume change (swelling / shrinking) due to adsorption / desorption (absorption / release) of the solvent. This volume change may be unilateral or reversible, but is preferably reversible.

  Specific monomers of the stimulus responsive compound (D) include the following. As a monomer for forming a temperature-responsive polymer gel, N-alkyl-substituted (meth) acrylamide such as N-isopropylacrylamide, (meth) acrylamide, (meth) acrylic acid and its salt, vinyl methyl ether, or octyl group, Examples include alkyl (meth) acrylates having a long-chain alkyl group such as a decyl group, a lauryl group, and a stearyl group.

  Examples of monomers that form a photoresponsive polymer gel include triarylmethane derivatives and spirobenzopyran derivatives.

  Monomers that form polymer gels that respond to current or electric field include amino-substituted (meth) acrylamides such as dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and dimethylaminopropyl. Examples include acrylate, styrene, vinyl pyridine, vinyl carbazole, and dimethylaminostyrene.

  Monomers that form a pH-responsive polymer gel include (meth) acrylic acid, (meth) acrylamide, hydroxyethyl (meth) acrylate, maleic acid, vinyl sulfonic acid, vinyl benzene sulfonic acid, polydimethylaminopropyl (meth) ) Acrylamide, (meth) acrylonitrile and the like.

  As the monomer for forming the ion-responsive polymer gel, the same monomers as those for forming the pH-responsive polymer gel described above can be used.

  As a monomer that forms a stimulus-responsive polymer gel that responds to a stimulus by adsorption and desorption of a chemical substance, a strong ionic monomer is preferable. Examples thereof include vinyl sulfonic acid, vinyl benzene sulfonic acid, and (meth) acrylamide alkyl sulfonic acid. Etc.

  As the monomer that forms a stimulus-responsive polymer gel that responds to a stimulus by a change in the solvent composition, most monomers that form a polymer gel are applicable. Swelling and shrinking can be caused by using a good solvent and a poor solvent.

  From the above characteristics of the stimulus-responsive polymer gel, N-isopropylacrylamide is particularly preferable as the stimulus-responsive compound (D) copolymerized with the linear molecule (B) (FIGS. 1 and 2). reference).

  When the stimuli-responsive compound (D) is copolymerized via the polymerizable functional group contained in the polymer cross-linking precursor (C) as described in the above preparation method, the stimuli-responsive compound (D) is constituted. A stimuli-responsive polymer crosslinked product (E) contained as a unit is obtained. In addition, the stimulus responsive compound (D) in the stimulus responsive polymer crosslinked product (E) exists in the form of a monomer or a polymer. The stimulus-responsive polymer crosslinked body film obtained by using this stimulus-responsive polymer crosslinked body (E) as a film has a larger swelling / shrinking behavior in response to the stimulus than the conventional stimulus-responsive polymer crosslinked body prepared by crosslinking. And has a feature that the shrinkage rate is remarkably high.

  For example, when N-isopropylacrylamide is used as the stimulus-responsive compound (D) and copolymerization is performed via the polymerizable functional group contained in the polymer cross-linking precursor (C) as described in the above preparation method, N -A cross-linked stimulus-responsive polymer (E) containing isopropylacrylamide as a structural unit is obtained. Note that N-isopropylacrylamide in the stimulus-responsive polymer crosslinked product (E) exists in the form of a monomer or a polymer. The stimuli-responsive polymer crosslinked product obtained by using this stimuli-responsive polymer crosslinked product (E) as a film changes significantly from transparent or translucent to white when heated to a high temperature, and the surface state is hydrophilic. Changes to hydrophobic. In addition, it exhibits a larger swelling / shrinkage behavior than a crosslinked stimulus-responsive polymer prepared by conventional crosslinking, and the shrinkage rate is remarkably fast.

An example of a cross-linked stimulus-responsive polymer (E) using N-isopropylacrylamide as the stimulus-responsive compound (D) is schematically shown in FIG. In the stimulus-responsive crosslinked polymer (E) shown in FIG. 2, the linear molecule (B) component copolymerized with the n-th monomer component of the polymer (BD ₁ ) containing N-isopropylacrylamide as a main component is derived. The side chain (B _X ) of this polymer is in a state of penetrating through one of the cyclic portions of the polymer (A). A blocking group is bonded to the end of the side chain (B _X ). Another cyclic part of the polymer (A) of the cyclic part that is included is in a state of being penetrated by the side chain (B _Y ) of another polymer (BD ₂ ) mainly composed of N-isopropylacrylamide. Yes. However, the stimulus-responsive polymer crosslinked product (E) is not limited to this structure.

  Specifically, the stimuli-responsive polymer crosslinked product (E) has a side chain of the first polymer having a blocking group at the end of the side chain skewed into one of the openings of the cyclic part in the polymer (A). The side chain of the second polymer having a blocking group at the end of the side chain penetrates like a skewer into another opening of the annular portion of the same polymer (A) (same polymer (A A) further includes an inclusion complex similar to the third polymer, the fourth polymer, the nth polymer, etc.), and at least 2 of the cyclic portion of the polymer (A) Each opening has a structure in which separate polymer side chains are included. Then, at least one position of the main chain or side chain of the n-th polymer (n is an integer including 1 and 2), or a portion (including the polymer chain) that connects these polymers to each other, is stimuli-responsive Compound (D) or a residue thereof is included. The side chain of the nth polymer is derived from the linear molecule (B). The obtained stimulus-responsive polymer crosslinked product (E) is a novel substance.

  The polymerization reaction of the linear molecule (B) and the stimulus-responsive compound (D) in the polymer crosslinking precursor (C) may be performed by a conventional method, for example, by radical polymerization. As such a reaction, for example, a solution containing the polymer crosslinking precursor (C) and the stimuli-responsive compound (D) may be added with a photopolymerization initiator if desired and irradiated with ultraviolet rays, or may be subjected to thermal polymerization. By adding the initiator and heating, the linear molecule (B) and the stimulus-responsive compound (D) are copolymerized.

  The photopolymerization initiator is not particularly limited as long as it is usually used, for example, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, Methyl benzoin benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β- Chloranthraquinone, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, (2,4,6-trimethylbenzyldiphenyl) Le) phosphine oxide, 2-benzothiazole -N, it can be used N- diethyldithiocarbamate and the like.

  On the other hand, the thermal polymerization initiator is not particularly limited as long as it is usually used. For example, benzoyl peroxide, azobisisobutyronitrile (AIBN), or the like can be used.

  The stimulation-responsive crosslinked polymer (E) may be purified by a conventional method, for example, sequentially washed with water, tetrahydrofuran and dimethylformamide.

  According to the above method, the polymer cross-linking precursor (C) can be produced simply by mixing and stirring the polymer (A) and the linear molecule (B) without synthesizing the pseudorotaxane. And a stimulus response including a rotaxane structure having an interlock structure by copolymerizing a linear molecule (B) of the obtained polymer crosslinking precursor (C) and a stimulus-responsive compound (D) The crosslinked polymer (E) can be easily produced.

  The obtained stimulus-responsive polymer crosslinked product (E) is excellent in flexibility because the cyclic portion of the polymer (A) can move on the side chain of the polymer. Therefore, the stimulus-responsive polymer crosslinked product ( The plastic material formed using E) has excellent stress relaxation properties. In addition, the obtained stimulus-responsive polymer crosslinked product (E) exhibits a large swelling / contraction behavior in response to a stimulus, and the contraction rate is significantly faster than a stimulus-responsive polymer crosslinked product prepared by conventional crosslinking. It has excellent properties. Further, when N-isopropylacrylamide is used as the stimulus responsive compound (D), the stimulus responsive polymer crosslinked product obtained by using the obtained stimulus responsive polymer crosslinked product (E) as a film is heated to a film. Is markedly changed from transparent or translucent to white and the surface state is changed from hydrophilic to hydrophobic.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, the stimuli-responsive polymer crosslinked product according to the present invention may be any as long as it has an interlock structure and contains a stimulus-responsive compound or a residue thereof in the skeleton. The aforementioned example has an interlock structure composed of a polymer (A) having two or more cyclic moieties and a linear molecule (B). The interlock structure is preferably a rotaxane structure, but may also be, for example, a catenane structure. Examples of the stimulus-responsive polymer cross-linked body having a catenane structure include those in which a stimulus-responsive compound is introduced into a portion where cyclic molecules having a catenane structure are linked to each other.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Synthesis of polymer (A) 5 g of α-cyclodextrin (manufactured by Nacalai Tesque) was dissolved in 50 ml of dimethylformamide, and to this solution was added tolylene 2,4-diisocyanate-terminated polypropylene glycol (manufactured by Aldrich, Mn: 1, 000) 3.4 g and 200 mg of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a tin catalyst were added and stirred at room temperature for 20 hours.

  The reaction solution is poured into diethyl ether to precipitate, and the collected solid is dried, washed with water and dried again, and a polymer (A) having α-cyclodextrin as a cyclic moiety and polypropylene glycol as a linking moiety molecule 4.6 g was obtained.

(2) Synthesis of linear molecule (B) 5 g of polyethylene glycol (manufactured by Wako Pure Chemical Industries, Mn: 1000) is dissolved in 50 ml of methylene chloride, and 3,5-dimethylphenyl isocyanate (manufactured by Aldrich) is dissolved in this solution. 1.6 g and 200 mg of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.) which is a tin catalyst were added and stirred at room temperature for 20 hours. Subsequently, 1.7 g of 2-methacryloyloxyethyl isocyanate (manufactured by Showa Denko KK, product name “Karenz MOI”) and 100 mg of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.) are added to the solution, and further stirred at room temperature for 20 hours. did. The obtained solution was concentrated and then precipitated in diethyl ether cooled to −75 ° C. to collect the precipitate. 3.8 g of polyethylene glycol having a group (hereinafter referred to as “MA-PEG-DPI”; linear molecule (B)) was obtained.

(3) Production of polymer cross-linking precursor (C) 300 mg of polymer (A) was dissolved in 1 ml of 0.4 wt% sodium hydroxide aqueous solution, and 200 mg of linear molecule (B) was added to this solution mechanically. When ultrasonic irradiation (35 Hz) was performed for 5 minutes while stirring, the solution became cloudy and the viscosity increased. Such a cloudy substance having increased viscosity is considered to be a polymer crosslinking precursor (C) in which the cyclic portion of the polymer (A) includes the linear molecule (B).

(4) Production of cross-linked stimulus-responsive polymer (E) 2.0 g of N-isopropylacrylamide as a stimulus-responsive compound (D) was added to the white turbid substance, and the mixture was stirred until it became uniform. Next, 40 μl of 1-hydroxy-cyclohexyl-phenyl-ketone / benzophenone eutectic mixture (product name “IRGACURE 500”, manufactured by Ciba Specialty Chemicals) which is a photopolymerization initiator is added, and after stirring, ultraviolet rays are applied for 3 minutes. Irradiation (irradiation conditions: illuminance: 3.0 mW / cm ² , light amount: 500 mJ / cm ² )

  The obtained substance is composed of the linear molecule (B) and the stimulus-responsive compound (D) via the polymerizable functional group (methacryloyl group) of the linear molecule (B) in the polymer crosslinking precursor (C). Stimulus responsive polymer cross-linked product (E) (polymer) is copolymerized with a side chain of a polymer having a blocking group at the end of the cyclic part of polymer (A), and a stimulus responsive compound (D ) Is a stimulus-responsive polymer cross-linked product (E)) comprising the main chain of the polymer.

  The obtained substance (stimulated responsive polymer crosslinked product (E)) was sequentially immersed in water, tetrahydrofuran and dimethylformamide, washed, and then dried to stimulate the responsive polymer crosslinked product (thickness: 1.0 mm). , Non-stretched).

[Comparative Example 1]
Except for using 44 mg of polyethylene glycol diacrylate (used as a crosslinked product that does not form an interlock structure) instead of the polymer (A) in Example 1, a stimuli-responsive polymer crosslinked product (thickness) was obtained in the same manner as in Example 1. (Size: 1.0 mm, non-stretched).

[Test Example 1] (Measurement of swelling rate)
The stimulus-responsive crosslinked polymer films obtained in Examples and Comparative Examples were immersed in water, and the water temperature was increased from room temperature to 50 ° C. at a temperature rising rate of 1 ° C./min. At that time, the mass of the stimulus-responsive polymer crosslinked film at each temperature was measured, and the swelling rate was calculated.

The swelling ratio was determined from the difference between the mass of the dried film (W _dry ) and the mass of the film after swelling (W _swell ). The calculation formula is as follows.
Swelling ratio _{[%] = {(W swell} -W dry) / W dry} × 100
The relationship between the temperature thus obtained and the swelling rate is shown in the graph of FIG.

  From the graph of FIG. 3, the stimulus-responsive polymer crosslinked product film of the example shows very large swelling / shrinkage behavior depending on the temperature as compared with the stimulus-responsive polymer crosslinked product film of the comparative example. I understand.

[Test Example 2] (Evaluation of shrinkage behavior)
The stimulation-responsive polymer crosslinked film (room temperature) obtained in Examples and Comparative Examples was immersed in water at 50 ° C., and the swelling rate S (t) was measured over time to calculate the shrinkage rate Sn.

The shrinkage rate Sn was obtained by the following formula.
Shrinkage rate Sn = swelling rate S (t) at time (t) / swelling rate S (max) in a completely swollen state (23 ° C.)
The relationship between the time thus obtained and the shrinkage rate Sn (shrinkage behavior) is shown in the graph of FIG.

  From the graph of FIG. 4, it can be seen that the stimulus-responsive polymer crosslinked product film of the example has a remarkably fast contraction rate with respect to the temperature stimulus as compared with the stimulus-responsive polymer crosslinked product film of the comparative example.

[Test Example 3] (Measurement of water droplet contact angle)
The contact angle meter (made by KRUSS, DSA100) at 23 ° C. (room temperature) and 60 ° C. (heating) was used for the contact angle with respect to pure water on the surfaces of the stimulus-responsive crosslinked polymer films obtained in Examples and Comparative Examples. ). The results are shown in Table 1.

  From Table 1, it can be seen that, in the stimulus-responsive polymer crosslinked film of the example, the surface state markedly changes from hydrophilic to hydrophobic by heating.

[Test Example 4] (Evaluation of transparency)
The stimulus-responsive polymer crosslinked product films obtained in Examples and Comparative Examples were heated from 23 ° C. (room temperature) to 60 ° C., and the appearance of the stimulus-responsive polymer crosslinked product film at that time was visually evaluated. As a result, in the stimulation-responsive polymer crosslinked product film of the example, the film changed significantly from transparent to white by heating. On the other hand, the stimulus-responsive polymer crosslinked film of the comparative example changed from transparent to thinly turbid (translucent). A photograph showing the state (transparent) before heating of the stimulus-responsive crosslinked polymer film obtained in the examples is shown in FIG. 5, and a photograph showing the state after heating (white) is shown in FIG.

  The present invention is suitable for the production of a crosslinked polymer excellent in stress relaxation and stimulus responsiveness. Moreover, the polymer crosslinked body obtained can be used as a film having excellent stimulus responsiveness, and is useful as a functional material used for sensors, gel materials, medical materials, and the like.

It is a schematic diagram which shows the manufacturing process of the stimulus responsive polymeric crosslinked body which concerns on one Embodiment of this invention. It is a schematic diagram which shows the structure of the stimulus responsive polymer crosslinked body which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the temperature of a stimulus responsive polymeric crosslinked body film, and a swelling rate. It is a graph which shows the relationship between the time of a stimulus responsive polymeric crosslinked body film, and shrinkage | contraction rate. In transparency evaluation of Test Example 4, it is a photograph showing a state (transparency) before heating of the stimulus-responsive crosslinked polymer film of the example. In evaluation of the transparency of Experiment 4, it is a photograph which shows the state (white) after a heating of the stimulus responsive polymer crosslinked body film of an Example.

Claims (9)

A polymer having two or more cyclic moieties and a linear molecule having a blocking group at one end and a polymerizable functional group at the other end are mixed to form an inclusion complex for all or part thereof Let
Next, a method for producing a crosslinked stimulus-responsive polymer, wherein the linear molecule and the stimulus-responsive compound are copolymerized via a polymerizable functional group of the linear molecule.   A cross-linked stimulus-responsive polymer having an interlock structure and containing a stimulus-responsive compound or a residue thereof in a skeleton.   The cross-linked stimulus-responsive polymer according to claim 2, which has a site cross-linked by a compound having an interlock structure.   The stimuli-responsive polymer crosslinked product according to claim 2 or 3, wherein the interlock structure is a rotaxane structure.   Obtained by mixing a polymer having two or more cyclic moieties and a linear molecule capable of forming an inclusion complex with the polymer having a blocking group at one end and a polymerizable functional group at the other end. It is obtained by copolymerizing the linear molecule and a stimulus-responsive compound via a polymerizable functional group of the linear molecule of the obtained polymer cross-linking precursor. Molecular cross-linked product. In the polymer having two or more cyclic parts, at least one side chain of the first polymer having a blocking group at the end of the side chain penetrates in an opening of the cyclic part, and the same cyclic A structure in which at least one side chain of the second polymer having a blocking group at the end of the side chain is penetrated in a skewered manner at the opening of at least one remaining annular portion of the polymer having a portion;
A stimuli-responsive compound or a residue thereof is contained in at least one of the first polymer, the second polymer, or the portion that binds the first polymer and the second polymer. A cross-linked stimulus-responsive polymer, characterized in that it has a plurality of portions.   The stimulus-responsive polymer crosslinked product according to claim 6, wherein the stimulus-responsive compound as a polymer constitutes a main chain of the first polymer and / or the second polymer. .   The cyclic portion of the polymer is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, or from the group consisting of cyclic polyether, cyclic polyester, cyclic polyetheramine and cyclic polyamine. The stimuli-responsive polymer crosslinked product according to any one of claims 5 to 7, which is at least one selected.   The stimuli-responsive polymer crosslinked product according to any one of claims 2 to 8, wherein the stimulus-responsive compound is N-isopropylacrylamide or a polymer thereof.