JP5142184B2 - A polymer compound obtained by crosslinking a polyester compound having a furan ring in the main chain with polyvalent maleimide - Google Patents

Description

  The present invention relates to a polymer compound obtained by crosslinking a polyester compound having a furan ring in the main chain with a polyvalent maleimide.

  Many of today's general-purpose plastics are made from petroleum resources. However, natural resources are limited, especially oil resources are feared to be exhausted. Therefore, there is a demand for the development of plastics that do not rely on petroleum resources.

  Currently, as a plastic from plant biomass, one using polylactic acid has been developed and already put into practical use. On the other hand, wood-based biomass, which is unused or incinerated, is present in a considerable proportion, so there is room for using it as a raw material.

  As plastic from wood-based biomass, the present inventor has reported the synthesis of a polyester compound using hydroxymethylfurfural (HMF) as a raw material obtained by pyrolyzing and purifying wood-based biomass (Non-patent Document 1). ).

  In Non-Patent Document 1, HMF is reduced to 2,5-bis-hydroxyfuran (BHF) by sodium hydride, and this BHF is used as a diol component to polycondense with succinic acid, fumaric acid or maleic acid which are dicarboxylic acids. Thus, a polyester compound having a furan ring in the main chain is synthesized.

The present invention has succeeded in producing a polymer compound by further crosslinking the polyester compound having a furan ring with a bismaleimide compound. And by heating this high molecular compound, it was made to dissociate bridge | crosslinking and succeeded in decomposing | disassembling the original polyester compound and a bismaleimide compound.
Polymer Papers, Vol.62, No.7, pp.316-320 (Jul., 2005)

An object of the present invention is to provide a recyclable plastic material using wood-based biomass as a raw material.
An object of the present invention is to provide a polymer compound obtained by crosslinking a polyester compound having a furan ring in the main chain with a polyvalent maleimide.
An object of this invention is to provide the method of manufacturing the high molecular compound which bridge | crosslinked the polyester compound which has a furan ring in a principal chain with polyvalent maleimide.

(1) The present invention
Esterifying 2,5-bishydroxymethylfuran and dicarboxylic acid to produce a polyester compound;
The present invention relates to a method for producing a polymer compound, which comprises crosslinking a furan ring in the polyester compound and a maleimide group in a polyvalent maleimide compound.

(2) The present invention
The dicarboxylic acid is of formula (I):

[Wherein R ¹ is a divalent linear hydrocarbon group having 1 to 18 carbon atoms which may or may not contain a double bond, a group — (CH═CH) _n1 —, or phenylene. Where n1 is an integer from 1 to 6]
And the polyester compound is of the formula (II):

[Wherein, m is an integer of 1 to 1000, and R ¹ is as described above]
It is related with the manufacturing method of the high molecular compound as described in said (1) which is a compound shown by these.

(3) The present invention
The polyvalent maleimide compound has the formula (III):

Wherein, ^{R 2} is unsubstituted or _C 1 -C ₆ alkyl substituted group - _{(CH 2) n2} -, unsubstituted or _C 1 -C ₆ alkyl substituted phenylene or a group, -X- Y-X-,
here,
n2 is an integer of 1 to 10,
X is phenylene unsubstituted or substituted with C ₁ -C ₆ alkyl, or

And
Y is a group — (CH ₂ ) _n3 —, —O—, —SO ₂ —, or a group that is unsubstituted or substituted with C ₁ -C ₆ alkyl.

And
n3 is an integer of 1 to 6]
Or a bismaleimide compound represented by formula (IV):

[Wherein n4 is an integer of 0 to 3]
It is related with the manufacturing method of the high molecular compound as described in said (1) or (2) which is a polyphenyl methane maleimide compound shown by these.

(4) The present invention
It is related with the high molecular compound obtained by the manufacturing method as described in any one of said (1)-(3).

  Since the raw material of the compound of the present invention is derived from wood-based biomass, the wood-based biomass to be disposed of can be effectively used. Moreover, since the high molecular compound of this invention can dissociate bridge | crosslinking by heat and can return to an original material, it can decompose | disassemble and recycle after utilization.

  2,5-bishydroxymethylfuran (BHF) used in the present invention is represented by the following chemical formula:

The method for obtaining 2,5-bishydroxymethylfuran (BHF) may be obtained from the market or prepared by oneself. As a method of preparing 2,5-bishydroxymethylfuran (BHF) by itself, there is a method of reducing 5-hydroxymethylfurfural (HMF) as shown in Scheme 1, It will not be limited if it is a method of obtaining bishydroxymethyl furan (BHF).

  5-hydroxymethylfurfural (HMF):

May be obtained from the market or prepared by yourself.

  As a non-limiting example, 5-hydroxymethylfurfural (HMF) may be obtained by high pressure pyrolysis of cellulose with supercritical water (K. Ehara and S. Saka, Cellulose, 2002, 9, 301). Alternatively, rice husk may be obtained by treatment at 260 ° C. using a batch reactor (K. Mochizuki, A Sakoda, and M. Suzuki, Adv. Environmental Res., 2003, 7, 421).

  Cellulose may be obtained from the market or prepared by itself. As a non-limiting example, cellulose may be obtained by destroying the lignin net by steam explosion or microwave of wood (Shitani Kitani, Biomass-Biological Resources and Environment-, Corona, 2004).

  The dicarboxylic acid used in the present invention is not limited as long as it is a compound having two carboxyl groups, but preferably the formula (I):

[Wherein R ¹ represents an unsubstituted divalent linear hydrocarbon group which may or may not contain a double bond, an unsubstituted group — (CH═CH) _n1 —, or unsubstituted phenylene. An unsubstituted divalent straight chain linear hydrocarbon group which may or may not contain a double bond or an unsubstituted group — (CH═CH) _n1 —, wherein double The carbon number of the unsubstituted divalent linear hydrocarbon group which may or may not include a bond is an integer of 1 to 18, preferably 1 to 12, more preferably 1 to 6, and a double bond The number is an integer of 1 to 16, preferably 1 to 10, more preferably 1 to 6, and n1 is an integer of 1 to 6, preferably 1 to 3.]
It is a compound shown by these.

Examples of dicarboxylic acids having an unsubstituted divalent linear hydrocarbon group that does not contain a double bond used in the present invention include malonic acid, succinic acid, and glutaric acid. ), Adipic acid, sebacic acid, pimelic acid, suberic acid, azelaic acid, 1,9-nonanedicarboxylic acid Acid), dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid , Octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid and the like. An example of a dicarboxylic acid having an unsubstituted divalent linear hydrocarbon group containing a double bond is traumatic acid. Examples of dicarboxylic acids having an unsubstituted group-(CH = CH) _n1- are maleic acid, fumaric acid and the like. An example of a dicarboxylic acid having unsubstituted phenylene is terephthalic acid. Examples of more preferred dicarboxylic acids are malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, pimelic acid, Suberic acid, traumatic acid, maleic acid, fumaric acid, terephthalic acid and the like. Examples of particularly preferred dicarboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, pimelic acid, Suberic acid. These dicarboxylic acids are commercially available.

  The esterification reaction used in the present invention means a reaction in which an ester bond is generated between a hydroxyl group in 2,5-bishydroxymethylfuran (BHF) and a carboxyl group in dicarboxylic acid.

  When the dicarboxylic acid is represented by a compound of formula (I), the esterification reaction of 2,5-bishydroxymethylfuran (BHF) with the dicarboxylic acid is illustrated as in Scheme 2.

  The polyester compound used in the present invention means a compound in which a hydroxyl group in 2,5-bishydroxymethylfuran (BHF) and a carboxyl group of a dicarboxylic acid are polymerized by an ester bond.

  When the dicarboxylic acid is represented by a compound of formula (I), the polyester compound is of formula (II):

[Wherein, m is an integer of 1-1000, preferably 2-1000, more preferably 10-1000, and R ¹ is as described above]
Indicated by

  The number of 2,5-bishydroxymethylfuran (BHF) and dicarboxylic acid participating in the production of the polyester compound used in the present invention is 1,5-bishydroxymethylfuran (BHF) being 1 or more, and the dicarboxylic acid If is 1 or more, it is not limited. Therefore, the polyester compound of the present invention means a compound produced by ester-linking one or more 2,5-bishydroxymethylfurans (BHF) and one or more dicarboxylic acids.

The molecular weight of the polyester compound of the present invention is not limited as long as it is a molecular weight of a polyester compound formed by ester-linking one or more 2,5-bishydroxymethylfurans (BHF) and one or more dicarboxylic acids, preferably 1 × 10 ³ to 1 × 10 ⁷ , more preferably 3 × 10 ³ to 1 × 10 ⁶ , and particularly preferably 3 × 10 ³ to 1 × 10 ⁵ .

  The method of synthesizing a polyester compound by polymerizing 2,5-bishydroxymethylfuran (BHF) and dicarboxylic acid is an esterification reaction that produces a polyester compound composed of 2,5-bishydroxymethylfuran (BHF) and dicarboxylic acid. There is no limitation as long as there is. The conditions used for the reaction, such as a solvent, a catalyst, a condensing agent, a reaction temperature, and a reaction time, are not limited as long as the conditions yield a polyester compound composed of 2,5-bishydroxymethylfuran (BHF) and a dicarboxylic acid.

  The polyvalent maleimide compound used in the present invention is not limited as long as it is a compound having two or more maleimide groups.

  A preferred polyvalent maleimide compound used in the present invention is represented by the formula (III):

Wherein, ^{R 2} is unsubstituted or _C 1 -C ₆ alkyl substituted group - _{(CH 2) n2} -, unsubstituted or _C 1 -C ₆ alkyl substituted phenylene or a group, -X- Y—X—, preferably a group — (CH ₂ ) _n2 —, which is unsubstituted or substituted with C ₁ -C ₆ alkyl, or a group —X—Y—X—
here,
n2 is an integer of 1 to 10,
X is phenylene which is unsubstituted or substituted with C ₁ -C ₆ alkyl, or an unsubstituted group

Preferably phenylene unsubstituted or substituted with C ₁ -C ₆ alkyl,
Y is a group — (CH ₂ ) _n3 —, —O—, —SO ₂ —, or an unsubstituted group, which is unsubstituted or substituted with C ₁ -C ₆ alkyl.

Preferably a group — (CH ₂ ) _n3 —, —O—, or —SO ₂ —, which is unsubstituted or substituted with C ₁ -C ₆ alkyl, more preferably unsubstituted or C ₁ -C _{A 6-} alkyl-substituted group — (CH ₂ ) _n3 —;
n3 is an integer of 1-6, preferably an integer of 1-3]
Or a bismaleimide compound represented by formula (IV):

[Wherein n4 is an integer of 0 to 3]
It is a polyphenyl methane maleimide compound shown by these.

Examples of bismaleimide compounds having a group — (CH ₂ ) _n2 — that are unsubstituted or substituted with C ₁ -C ₆ alkyl for use in the present invention are 1,6-bismaleimide hexane, 1,6′-bismaleimide- (2,2,4-trimethyl) hexane and the like. Examples of bismaleimide compounds having phenylene unsubstituted or substituted with C ₁ -C ₆ alkyl are m-phenylene bismaleimide, 4-methyl-1,3-phenylene bismaleimide and the like. Examples of bismaleimide compounds having the group -X-Y-X- are 4,4'-bismaleimide diphenylmethane, 4,4'-diphenylmethane bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5 '-Diethyl-4,4'-diphenylmethane bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenylsulfone bismaleimide, 1,3-bis (3-maleimidophenoxy) benzene, 1,3-bis (4-maleimidophenoxy) benzene and the like. The polyphenylmethane maleimide having the formula (IV) may be a mixture of n4 = 0-3. The average of n4 preferable in the case of a mixture is about 1.2. Examples of more preferred polyvalent maleimide compounds include 4,4′-bismaleimide diphenylmethane, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethane bismaleimide, 1,6-bismaleimide hexane, 1,6′-bismaleimide- (2,2,4-trimethyl) hexane, polyphenylmethane maleimide. These polyvalent maleimide compounds are commercially available.

  To crosslink the furan ring in the polyester compound and the maleimide group in the polyvalent maleimide compound used in the present invention means to crosslink by a Diels-Alder reaction.

  The Diels-Alder reaction is a [4 + 2] cycloaddition reaction of a diene and a dienophile (parent diene), which is a cycloaddition reaction that converts three π bonds into two σ bonds and one new π bond (Kloetzel). , MC Org. React. 1948, 4, 1 .; Holms, HL Org. React. 1948, 4, 60 .; Martin, JG Chem. Rev. 1961, 61, 537 .; Sustman, R. et al. Angew. Chem. Int. Ed. Engl. 1980, 19, 779.). The reaction proceeds only with heat, and the reaction proceeds even without a catalyst. A Lewis acid may be added as a catalyst.

  Moreover, in this Diels-Alder reaction, although two types of stereoisomers, an endo body and an exo body, may be produced, both are included in the present invention.

  If the crosslinking reaction between the furan ring in the polyester compound and the maleimide group in the polyvalent maleimide compound is a Diels-Alder reaction, the conditions for the Diels-Alder reaction, such as solvent, reaction temperature, reaction pressure, reaction time, etc. are limited. Not.

  The cross-linking of the furan ring in the polyester compound and the maleimide group in the polyvalent maleimide compound used in the present invention, even if all of the furan ring and the maleimide group participate in the cross-linking, only a part participates in the cross-linking. May be.

  Therefore, the ratio of the maleimide group and the furan ring that can be used in the Diels-Alder reaction for crosslinking the furan ring in the polyester compound and the maleimide group in the polyvalent maleimide compound is not limited as long as it can be crosslinked. , Preferably maleimide group: furan ring = 0.01 to 10: 1, more preferably 0.1 to 5: 1, particularly preferably 0.4 to 2: 1.

  When all furan rings in the polyester compound and all maleimide groups in the bismaleimide compound participate in crosslinking, the polymer compound of the present invention has the formula (V):

[Wherein R ¹ , R ² and m are as described above]
It is a compound shown by these.

  The number of polyester compounds and polyvalent maleimide compounds participating in the formation of the polymer compound of the present invention is not limited as long as the polyester compound is 2 or more and the polyvalent maleimide compound is 1 or more. Accordingly, the polymer compound of the present invention means a compound formed by crosslinking two or more polyester compounds and one or more polyvalent maleimide compounds.

  The molecular weight of the polymer compound of the present invention is not limited as long as it is a molecular weight of a polymer compound formed by crosslinking two or more polyester compounds and one or more polyvalent maleimide compounds.

  In the polymer compound of the present invention, the crosslinking between the furan ring and the maleimide group in the polymer compound is dissociated at 50 ° C to 300 ° C, preferably 100 ° C to 200 ° C, more preferably 120 ° C to 180 ° C. Thus, the compound can return to the original polyester compound and polyvalent maleide compound. This dissociation of the bridge may be a partial dissociation.

  The production method of the polymer compound may include a step of purifying the produced polymer compound in addition to the reaction of crosslinking the furan ring in the polyester compound and the maleimide group in the polyvalent maleide compound.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Reagents 4,4'-Bismaleimidodiphenylmethane (Japanese name: 4,4'-bismaleimidodiphenylmethane)
Tokyo Chemical Industry (B1109)
・ 1,6-BIsmaleimidohexane (Japanese name: 1,6-bismaleimidohexane)
Tokyo Chemical Industry (B1787)

  NMR measurement was performed using a 600 MHz JNM-ECP600 spectrometer manufactured by JEOL Ltd. Moreover, the measurement was performed at room temperature (24 ° C.) unless otherwise specified.

  In order to investigate the thermal characteristics, measurements were made with a differential scanning calorimeter (DSC). DSC was measured using a Pyris 1 DSC apparatus manufactured by Perkin Elmer Co.

The molecular weight was calculated in terms of polystyrene using chloroform as a solvent using an LC10AD high performance liquid chromatograph manufactured by Shimadzu Corporation (column: TSKgel Multipore H _XL -M x 3 manufactured by Tosoh Corporation).

1. Synthesis of 2,5-bishydroxymethylfuran (BHF) 5-hydroxymethylfurfural (HMF) (ALDRICH, product number H40807-5G) is reduced to obtain 2,5-bishydroxymethylfuran (BHF). It was.

  Specifically, sodium borohydride (6.1 g, 160 mmol) was divided into several times in a mixture of dehydrated methanol (70 ml) and 1N aqueous sodium hydroxide solution (0.2 ml) in an ice bath under a nitrogen stream. The mixture was stirred for a while and the temperature of the solution was kept at about -10 ° C. A solution of dehydrated methanol (20 ml) in which HMF (10.3 g, 82 mmol) was dissolved was slowly added dropwise thereto, and the dropping funnel was washed with 5 ml of dehydrated methanol and added to the reaction solution. After confirming that the spot of the raw material had completely disappeared by TLC, the solvent was removed by an evaporator. After extraction with ethyl acetate, the extract was washed with saturated brine, dried over sodium sulfate, and then ethyl acetate was removed by an evaporator. The residue was dissolved in chloroform and recrystallized several times to obtain BHF as white crystals. Yield was 9.4 g (89.4%). The results of NMR measurement by dissolving in deuterated methanol are shown in FIGS. 1 and 2 below.

3. Synthesis of polyester compound 3-1. Synthesis of polyester compound by polymerization of BHF and succinic acid, fumaric acid (FA) or maleic acid (MA) Polymerization of BHF synthesized in 2 above and dicarboxylic acid was performed. As the dicarboxylic acid, succinic acid (SA), fumaric acid (FA), and maleic acid (MA) are selected. Dicyclohexylcarbodiimide (DCC) is used as a condensing agent, dimethylaminopyridine (DMAP) is used as a catalyst, and 1,2-dichloroethane ( A solvent dehydrated DCE) was used.

First, the monomer carboxylic acid and BHF, DCC, and DMAP were placed in a reaction vessel (round bottom flask), and the reaction vessel was shielded from light with aluminum foil. Thereafter, deaeration and argon replacement were sufficiently performed to perform argon replacement. The solvent was added with a syringe and reacted for one day. After the reaction, the solution was added to a large amount of methanol and stirred vigorously to obtain a precipitate. The precipitate obtained by centrifugation was dissolved in chloroform, and if there was something that did not dissolve, it was filtered using a Kiriyama funnel, and the resulting chloroform filtrate was reprecipitated with a large amount of methanol again. . The operation of reprecipitation was repeated three times or more in total, and the resulting precipitate (polyester compound) was dissolved in chloroform, and the molecular weight was measured by chloroform-based GPC. Table 1 shows the number average molecular weight M _n and the degree of polymerization DP _n calculated from the M _n .

As a result, when succinic acid was reacted with a small amount of dichloroethane, a compound having the highest molecular weight such as a number average molecular weight M _n 6300 and a polymerization degree DP _n 30 could be obtained.

  No. When 2 and 3 were compared, a higher molecular weight could be obtained by performing at room temperature without heating.

  The yield is also No. Since the yield of 2 was higher, it can be said that the reaction with a small amount of solvent without heating was able to obtain the highest molecular weight efficiently.

No. in Table 1 The polyester compound obtained in 1 was dissolved in deuterated chloroform containing a standard substance TMS (tetramethylsilane, MERCK), and the results of ¹ H NMR and ¹³ C NMR measurement are shown in FIGS.

  As described above, it was possible to obtain a polyester compound as a solid using diol BHF that can be synthesized from biomass and succinic acid, fumaric acid (FA) or maleic acid (MA) of dicarboxylic acid.

3-2. Synthesis of polyester compounds using different condensing agents Polymerization with various condensing agents was performed. Polymerization was performed with 1-ethyl-3- (3-dimethylamidopropyl) carbodiimide hydrochloride (EDC)), which is a water-soluble carbodiimide used as a condensing agent for peptide synthesis. EDC is said to be easy to purify the product because urea as a by-product is water-soluble. EDC (1.54 g, 8.1 mmol) and DMAP (23 mg, 0.2 mmol) are added to BHF (514 mg, 4.0 mmol) and succinic acid (465 mg, 4.0 mmol), and 2 ml of dichloroethane (DCE) is used as a solvent. And allowed to react at room temperature for 24 hours. A white precipitate had formed. About 5 ml of chloroform was added to the solution after the reaction to dissolve the precipitate, followed by washing with 0.5 M hydrochloric acid aqueous solution, saturated brine, sodium bicarbonate aqueous solution, and finally saturated brine again, and sodium sulfate was added to the organic layer. And dried overnight. Sodium sulfate was removed by filtration, and the solvent was removed with an evaporator. It was again dissolved in chloroform and GPC measurement was performed. The number average molecular weight M _n was about 2400, and the degree of polymerization DP _n could be calculated as 12. Similarly, the results of experiments conducted by increasing the amount of DMAP are also shown in Table 2, but there was no significant change in molecular weight.

3-3. Polymerization of Polyester Compound In the above 3-1, 3-2, polymerization with monomers was attempted, but the molecular weight was increased to about 6000. However, in order to synthesize a higher molecular weight, not only polymerization of monomers but also further polymerization using a polymer (polyester compound) once polymerized was attempted. First, the following three types were tested: one in which BHF was added to the polyester compound, one in which succinic acid was added, and one in which no monomer was added.

3-3-1. Polymerization of polyester compound and BHF First, dichloroethane (DCE) was used as a solvent. However, the solubility of the polyester compound in DCE is low. This can be seen from the fact that solids are observed after the reaction even in the usual polymerization of BHF and dicarboxylic acid between monomers.

  The experimental conditions are summarized in Table 3 below.

No. 1 corresponds to No. 1 in 3-1. BHF (0.26 g, 2.0 mmol) was added to a polyester compound (0.11 g) having a number average molecular weight _{Mn of} about 3800 obtained in 1, DCC (0.43 g, 2.1 mmol), DMAP (0.01 g). 0.1 mmol) and DCE (2 ml) were added, and the reaction was carried out at room temperature for 24 hours. The product was dissolved in chloroform in the same manner as the polymer synthesis from the monomer, reprecipitated with methanol, dried, and then measured by GPC. Here, the number average molecular weight M _n was about 5200.

On the other hand, no. 2 is the same as in the previous experiment. When the molecular weight obtained in 2 was about 6300 and the molecular weight was higher than that of the previous one, the reaction temperature was 40 ° C., and BHF was added to carry out the polymerization, the number average molecular weight M _n by GPC was about 7500.

  In two experiments using DCE as a solvent, the molecular weight increase is only about 1000.

On the other hand, an experiment using dichloromethane (DCM) as a solvent was also conducted. The reason why the solvent was DCM was that the polyester compound was easier to dissolve in DCM than in DCE, so the reaction was thought to proceed more easily. Therefore, no. 3, DCE no. When polymerization was carried out using a polyester compound (0.12 g) having the same number average molecular weight Mn6300 as 2, the number average molecular weight _Mn was about 12,000, which was about twice that of the first used polyester compound.

  Here, no. Comparing 1, 2 and 3, it is considered that there was a difference in easiness of elongation due to solubility problems. No. When the solvent was changed to DCM in 3, the molecular weight was just doubled, so the polyester compounds were polymerized, and it was thought that two polyester compounds with an average of about 6300 were polymerized. It is conceivable that the molecular weight was 12000.

3-3-2. Polymerization of polyester compound and dicarboxylic acid Contrary to 3-3-1, succinic acid was added as follows.

  No. in Table 4 4-6, all of No. 3-1 above. The molecular weight of about 6300 obtained in 2 was used. No. When the reaction temperature was changed between 4 and 5, the yield was lower at room temperature, but an increase in molecular weight was observed. On the other hand, in the experiment in which the BHF was added earlier, the reaction was performed under the same conditions as when the molecular weight was extended about twice, but the reaction conditions were room temperature and the solvent was DCM. In the case of 6, the elongation was about 2000.

3-3-3. Polymerization between polyester compounds Using two types of polyester compounds, DCC and DMAP were added to conduct experiments.

  A slight increase in molecular weight was also observed due to the condensation reaction between the polyester compounds.

  The above three types of experiments are cases where the polyester compound obtained by once polymerization is further polymerized, but the polyester compound obtained in 3-3-1 and 3-3-2 is 1 It is considered that there is a high possibility that the terminals are aligned with the hydroxyl group and the carboxyl group, respectively, because an excessive amount of monomers is added. Therefore, it was thought that a polymer with a longer molecular weight could be obtained by polymerizing the polyester compound obtained in 3-3-1 and the polyester compound obtained in 3-3-2 as follows. .

Polymerization of the polyester compound obtained in 3-3-4.3-3-1 and the polyester compound obtained in 3-3-2 Experimental conditions and results are shown in Table 6 below. Here, No. 3-3-1. 2 (number average molecular weight Mn 7,500) and No. 3-3-2. When an experiment was conducted using polyester compounds having 5 (number average molecular weight Mn 7,200), a polyester compound having a number average molecular weight Mn of about 14,000 could be obtained.

  As described above, it was possible to synthesize a polyester compound from diol-form BHF that can be synthesized from biomass and dicarboxylic acid. In addition, a polyester compound having a molecular weight exceeding 10,000 could be synthesized by further polymerizing the polyester compound.

4). Synthesis of Polymer Compound by Reaction of Polyester Compound and Bismaleimide Compound The polyester compound synthesized in the above 3 has a furan ring derived from the diol BHF in its main chain. The Diels-Alder reaction using the furan ring was investigated.

  When a bismaleimide compound having two maleimide groups is used and a Diels-Alder reaction occurs between the maleimide groups on both sides thereof, polyester compounds are connected, that is, a crosslinked polymer compound can be obtained.

  First, 4,4′-bismaleimide diphenylmethane (Tokyo Kasei: product number B1109) having two maleimide groups and a polyester compound of BHF and succinic acid polymerized in the above 3 were once dissolved in chloroform, and 24 ° C. at 24 ° C. Heated for hours.

  Specifically, in a sample tube, a polyester compound (0.0142 g) having a number average molecular weight Mn of about 3500 (No. 5 in Table 2) and 4,4′-bismaleimide diphenylmethane (0.005 g, 0.013 mmol). ) And further chloroform (2 ml) was added to dissolve the solid polyester compound and maleimide. Then, without adding a stirrer or the like, it was placed in an oil bath heated to 80 ° C. and taken out after 24 hours.

  Thereafter, an attempt was made to dissolve the product with chloroform, methanol, water, etc., but there were some which did not dissolve. By irradiating with ultrasonic waves for a while with an ultrasonic cleaner (Tokyo Glass Instruments Co., Ltd. Fu-9H), the film-like polymer compound of the present invention at the bottom of the sample tube could be obtained.

  For this experiment, several reactions were performed under different conditions. The experimental conditions are shown in Table 7.

  Here, no. In the case of 1, 2 and 4, a film-like polymer compound of the present invention was formed. As for No. 3, it did not become a film, but when irradiated with ultrasonic waves, a yellow solid was obtained.

  No. 1 and No. 2 and No. 2 No. 1 was a film that did not break even when folded by hand. 2 broke when folded by hand.

  From these two, if this film-like solid is produced by crosslinking by Diels-Alder reaction, the properties of the product are not different due to the difference in the degree of crosslinking. I can think.

  No. 1 and No. 2 and No. 2 2 adds more maleimide groups to the furan ring. This 2: 1 ratio is just the amount by which all the furan rings of the polyester compound react with all the maleimide groups of the bismaleimide compound. Therefore, no. It is thought that the reaction was more likely to occur than 1 and the degree of crosslinking was increased.

  In addition, No. 1 was reacted at different temperatures. 1, No. 1 3, No. 4 was compared, no film-like solid was formed at 70 ° C. In No. 3, the reaction rate of the Diels-Alder reaction was low, that is, the polymer chains were not so much cross-linked, so there was some cross-linking, so an insoluble solid could be formed, but the degree of cross-linking was It was thought that it was not enough to become a film-like solid because it was not sufficient.

5. Reverse Diels-Alder Reaction of Polyester Compound and Bismaleimide Compound This insoluble product (polymer compound of the present invention) obtained by the reaction of polyester compound and bismaleimide compound (4,4′-bismaleimide diphenylmethane) is obtained. It is considered that the reverse Diels-Alder reaction occurs by heating, and a polyester compound and a bismaleimide compound can be obtained.

  No. in Table 7 1, the film synthesized at a ratio of maleimide group: furan ring = 0.4: 1 was cut off with scissors, 0.0018 g was put into a sample tube, and 1 ml of chloroform was added.

  The sample tube was placed in a 100 ml eggplant flask having a wide mouth and immersed in an oil bath heated to 150 ° C. for 20 minutes. The reverse reaction was carried out at 140 ° C., but this time, since the sample tube was put in the eggplant flask, it was difficult to transfer heat, so the temperature of the oil bath was set to a slightly high temperature. Then, it was immediately put into a Dewar bottle containing a solution of ethanol mixed with dry ice and rapidly cooled. GPC measurement was performed by dissolving in chloroform (FIG. 6).

  We also examined what is called the Retro Diels-Alder reaction, not the reverse Diels-Alder reaction. According to a report by Gheneim et al., By adding N-phenylmaleimide, which is a monomaleimide compound, to a polyester compound chain cross-linked with a bismaleimide compound, instead of the site where the bismaleimide compound reacted, the monomaleimide The compound reacts to cause a dissociation reaction (Jeffrey R. Jones, Charles L. Liotta, David M. Collard, and David A. Schiraldi, Macromolecules, 1999, 32, 5786-5792).

  First of all, the sample tube No. 0.0018 g of the cut film obtained in 1 was added, 0.0072 g of N-Phenylmaleimide, which is a monomaleimide compound, was added in an excessive amount, and 1 ml of chloroform was added. As before, the sample tube was placed in the eggplant flask and placed in an oil bath heated to 150 ° C. Then, it dissolved in chloroform and measured GPC (FIG. 7).

In the case of the polyester compound, the first peak shows the peak of the polyester compound having the number average molecular weight Mn3400 (FIG. 5). The first peak in the case of the reverse Diels-Alder reaction was measured as the number average molecular weight Mn3300 (FIG. 6), and the first peak in the case of the Retro Diels-Alder reaction was measured as the number average molecular weight Mn4200. (FIG. 7). The molecular weight (number average molecular weight Mn3300) of the product obtained by the reverse Diels-Alder reaction is considered to be almost the same as the molecular weight of the polyester compound (number average molecular weight Mn3400), but the product obtained by the Retro Diels-Alder reaction ( The number average molecular weight Mn4200) shows an increase in molecular weight. This is probably because the monomaleimide compound reacted in place of the bismaleimide compound at the site where the bismaleimide compound of the polyester compound chain had reacted. In addition, looking at the state of the peak, in the Retro Diels-Alder reaction, the peak has begun, although slightly, from an early time. In the reverse Diels-Alder reaction, since a shoulder is seen on the polymer side of the first peak around 28 minutes, there is a possibility that another peak exists here. Moreover, a peak appears in the vicinity of 30.9 minutes in both the reverse Diels-Alder and Retro Diels-Alder reactions, and this has a number average molecular weight _Mn of about 350. From this, it is highly possible that this peak is a peak of 4,4′-bismaleimide diphenylmethane, which is a bismaleimide compound, and a large peak that is visible after 32 minutes in the Retro Diels-Alder reaction was excessively added. It is thought that it is N-phenylmaleimide which is a monomaleimide compound.

  Therefore, in the reverse Diels-Alder reaction, the crosslinking in the polymer compound of the present invention is dissociated to form a polyester compound and a bismaleimide compound. In the Retro Diels-Alder reaction, the crosslinking in the polymer compound of the present invention is generated. Is dissociated to form a polyester compound and a bismaleimide compound which are cross-linked with the monomaleimide compound.

6). Reaction with other bismaleimide compounds So far, bismaleimide compounds having a benzene ring have been reacted, but bismaleimide compounds having no benzene ring (1,6-bismaleimide hexane, Tokyo Kasei: product number B1787) The reaction with was also performed.

  In a sample tube, 1,6-bismaleimide hexane (0.008 g, 0.03 mmol) and a polyester compound having a number average molecular weight Mn of 5200 (0.012 g) (No. 7 in Table 4) were placed and dissolved in chloroform (2 ml). The reaction was carried out in an oil bath at 80 ° C. for 24 hours without stirring. Although solid chloroform was added, there was a solid that did not dissolve. However, this did not form a film like the bismaleimide compound having a benzene ring. NMR of the substance dissolved in deuterated chloroform was measured, but no peak of the polyester compound could be observed. This solid is also considered to be the polymer compound of the present invention obtained by the Diels-Alder reaction. In this case, the film was not formed because of the presence or absence of a benzene ring. Since the benzene ring has π-electrons, it has the property of being easily overlapped. Therefore, in addition to the crosslinking of the polymer chain itself, it is considered that the film could be formed into a film.

7). Conclusion As described above, the polymer compound of the present invention could be produced by crosslinking the furan ring of the polyester compound synthesized in the above 2 and the maleimide group of the bismaleimide compound by using the Diels-Alder reaction.

  Further, by applying further heat, it was possible to dissociate the crosslinking in the polymer compound of the present invention and decompose it into the original polyester compound and bismaleimide compound.

  The polymer compound of the present invention can be used as a recyclable plastic material.

¹ H-NMR of BHF in deuterated methanol (24 ° C., TMS standard) ¹³ C-NMR of BHF in deuterated methanol (24 ° C., TMS standard) No. in Table 1 in deuterated chloroform. 1 ¹ H NMR (24 ° C., TMS standard) No. in Table 1 in deuterated chloroform. 1 ¹³ C NMR (24 ° C., TMS standard) GPC measurement result of polymer used in Diels-Alder reaction (reference material: polystyrene) (24 ° C.) column: Tosoh TSKgel Multipore H _XL -M x 3), solvent: chloroform, flow rate: 1 ml / min, reference material: polystyrene : SHODEX standard polystyrene (Showa Denko) GPC measurement result (reference material: polystyrene) (24 ° C.) column with reverse Diels-Alder column: TSKgel Multipore H _XL -M x 3) manufactured by Tosoh, solvent: chloroform, flow rate: 1 ml / min, reference material: polystyrene: SHODEX standard polystyrene (Showa Denko) GPC measurement result (reference material: polystyrene) (24 ° C.) column after Retro Diels-Alder reaction: Tosoh TSKgel Multipore H _XL -M x 3), solvent: chloroform, flow rate: 1 ml / min, reference material: polystyrene : SHODEX standard polystyrene (Showa Denko)

Claims (4)

Esterifying 2,5-bishydroxymethylfuran and dicarboxylic acid to produce a polyester compound;
A method for producing a polymer compound, comprising crosslinking a furan ring in a main chain of the polyester compound and a maleimide group in a polyvalent maleimide compound by a Diels-Alder reaction . The dicarboxylic acid is of formula (I):

[Wherein R ¹ is a divalent linear hydrocarbon group having 1 to 18 carbon atoms which may or may not contain a double bond, a group — (CH═CH) _n1 —, or phenylene. Where n1 is an integer from 1 to 6]
And the polyester compound is of the formula (II):

[Wherein, m is an integer of 1 to 1000, and R ¹ is as described above]
The manufacturing method of the high molecular compound of Claim 1 which is a compound shown by these. The polyvalent maleimide compound has the formula (III):

Wherein, ^{R 2} is unsubstituted or _C 1 -C ₆ alkyl substituted group - _{(CH 2) n2} -, unsubstituted or _C 1 -C ₆ alkyl substituted phenylene or a group, -X- Y-X-,
here,
n2 is an integer of 1 to 10,
X is phenylene unsubstituted or substituted with C ₁ -C ₆ alkyl, or

And
Y is a group — (CH ₂ ) _n3 —, —O—, —SO ₂ —, or a group that is unsubstituted or substituted with C ₁ -C ₆ alkyl.

And
n3 is an integer of 1 to 6]
Or a bismaleimide compound represented by formula (IV):

[Wherein n4 is an integer of 0 to 3]
The manufacturing method of the high molecular compound of Claim 1 or 2 which is a polyphenylmethane maleimide compound shown by these.   The high molecular compound obtained by the manufacturing method of any one of Claims 1-3.