JPS5835526B2 - Method for producing poly-2,3-dihydrofuran - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides poly-2,3-
The present invention relates to a method for producing dihydrofuran, and more specifically, to a method for producing poly-2,3-dihydrofuran in one step by monomer isomerization polymerization using 2,5-dihydrofuran as a raw material. .

2. Poly-2 is produced by cationic polymerization of 3-dihydrofuran.
, 3-dihydrofuran is known (D
, A. Barr and J.B. Roee, J.

Chem-) 5oc-[London], 1954
) 3766).

However, 2,3-dihydrofuran is an unstable compound and has poor storage stability, and the polymerization reaction proceeds instantaneously at room temperature, making it difficult to control and causing problems such as coloring of the product. be.

For this reason, it was necessary to keep the reaction temperature sufficiently low.

On the other hand, 2゜5-dihydrofuran, which is an isomer of 2,3-hydrofuran, is a relatively stable compound and shows almost no polymerization ability when used alone.
is known to be converted to dihydrofuran (e.g. A, J. Hubert et al., J-Che
m, , Ferkin II, 1972 (4)
, 366), it is conceivable to isomerize 2,5-dihydrofuran to form 2°3-dihydrofuran, and then polymerize this to form poly-2,3-dihydrofuran.

However, in the isomerization reaction of 2,5-dihydrofuran, for example, in the method of A. J. Hubert mentioned above, a considerable amount of an isomerization catalyst such as iron pentacarbonyl (
There is a problem in that it is used in an amount of about 10% by weight based on 2,5-dihydrofuran.

In addition, the above-mentioned problems still remain in the polymerization of 2,3-dihydrofuran.

The present invention achieves monomer isomerization polymerization of 2,5-dihydrofuran by simultaneously carrying out the isomerization of 2,5-dihydrofuran and the polymerization of 2,3-dihydrofuran produced by the isomerization. By doing so, these problems were solved.

The present invention achieves efficient monomer isomerization polymerization of 2,5-dihydrofuran in the presence of iron pentacarbonyl, a Friedel-Crafts type catalyst, and/or an alkyl metal compound, and under irradiation with light. There are many ways to obtain poly-2,3-dihydrofuran.

The polymerization reaction of the method of the present invention is explained using a reaction formula as follows.

Examples of Friedel-Crafts type catalysts used in the present invention include boron trifluoride, boron trifluoride complexes with ethers, alcohols, phenols, amines, etc., tin tetrachloride, titanium tetrachloride, aluminum chloride, zinc chloride, etc. can do.

Examples of the alkyl metal compounds include alkyl aluminum compounds such as diethyl aluminum chloride, ethyl aluminum dichloride, and ethyl aluminum sesquichloride.

The amount of iron pentacarbonyl, Friedel-Crafts type catalyst and/or alkyl metal compound used is 2,
It ranges from 0.01 to 2% by weight, preferably from 0.05 to 1% by weight, based on 5-dihydrofuran.

These ranges are not necessarily critical, but if they are less than this, the reaction progresses slowly.

Moreover, if it exceeds this range, the yield will decrease and it is not a good idea from an economic point of view.

There are no particular limitations on the ratio of the amount of iron pentacarbonyl used as a catalyst and the order of addition of both catalysts, and each catalyst can be arbitrarily selected within the range of the amount used above and added in any order. It's fine.

The monomer isomerization polymerization reaction of the present invention needs to be carried out under light irradiation.

As a light source, direct sunlight, thallium lamp, tungsten lamp, ultra-high pressure mercury lamp, high pressure mercury lamp, etc. may be used.
It is preferable to use a high-pressure or ultra-high-pressure mercury lamp, a thallium lamp, or the like that can irradiate light with a wavelength of 150 μm to 580 μm, preferably including ultraviolet light.

Although the monomer isomerization polymerization reaction of the present invention may be carried out without a solvent by bulk polymerization, it is preferably carried out in the presence of a solvent.

As a solvent, benzene, toluene, chlorobenzene,
Methyl chloride, methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, hexane, heptane, and the like can be used.

Although the amount used is not limited, it is convenient to add it so that it accounts for about 9 to about 95% by volume of the total amount of liquid in the polymerization reaction system.

The monomer isomerization polymerization reaction of the present invention is preferably carried out under an atmosphere of an inert gas such as nitrogen or argon, avoiding contact with moisture.

It may be carried out under a gas atmosphere of the solvent used.

Although the presence of air is not necessarily prohibited, it is preferable to avoid it since it may react with the catalyst and the like.

The reaction is usually carried out at a temperature of about -90°C to about 60°C, preferably about -30°C to about 40°C.

The polymer produced by monomer isomerization polymerization of the present invention is
It is a white powder and can be prepared by a known method (D, A, Barrand
J.B.Rose, J.Chem-Soc.
[London,] 1954, 3766), polyJ-2,3 dihydrofuran obtained by cationic polymerization of 2,3-dihydrofuran, nuclear magnetic resonance absorption spectrum, infrared absorption spectrum, elemental analysis, softening point, etc. Match.

Therefore, this polymer is not a compound polymerized by cleavage of the ether ring, but has a structure in which the double bond portion is addition-polymerized, as described in the reaction formula above.

The poly-2,3-hydrofuran thus obtained can be used for various purposes, such as as a film or molded product, or as a modifier for other polymers.

In particular, it shows good compatibility with polyvinyl chloride because its structure is similar to that of tetrahydrofuran, which is a good solvent for polyvinyl chloride.

According to the method of the present invention, when a combination of the above-mentioned known methods is used, 2,5-dihydrofuran is isomerized to 2,3-dihydrofuran, which is further polymerized to produce polyIJ--2,3-dihydrofuran. - Compared to the case of using dihydrofuran, the process can be shortened.

Furthermore, it is expected that the amount of iron pentacarbonyl used as an isomerization catalyst is sufficient to be 1/1000 to 1/2 of the amount used when 2,5-dihydrofuran is simply isomerized to obtain 2,3-dihydrofuran. It has an effect that cannot be obtained.

Furthermore, the isomerization reaction of the present invention can be carried out stably at room temperature or higher, completely eliminating the difficulty of controlling the polymerization rate, which is a problem when polymerizing 2,3-dihydrofuran. can be avoided.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 5 d of purified benzene and 0.
01069, iron pentacarbonyl 0.01959 and 2
, 2.789% of 5-dihydrofuran were sequentially added, the tube was sealed, and a high-pressure mercury lamp for physics and chemistry (100W) was added.

Manufactured by Tokyo Shibaura Electric Co., Ltd., 5HL-100UV 2
) was submerged in a constant temperature water bath at 20° C., and was irradiated with ultraviolet rays from this high-pressure mercury lamp to carry out monomer isomerization polymerization.

After continuing the reaction for 24 hours, the container was opened, the contents were poured into n-hexane, and the precipitate was separated and vacuum-dried at room temperature to obtain white powdered polymer 269.

The conversion rate for the charged 2,5-dihydrofuran was 93
．． 9%, intrinsic viscosity measured at 30°C in chloroform is 0.
．． It is 40dL/9.

The obtained polymer is soluble in chloroform, carbon tetrachloride, tetrahydrofuran, dioxane, benzene, etc., and insoluble in water, methanol, n-hexane, acetone, dimethyl sulfoxide, dimethyl formamide, ethyl ether, etc. Ta.

When we measured the infrared absorption spectrum and nuclear magnetic resonance absorption spectrum of this polymer, we found that the infrared absorption spectrum showed that the wavenumber was 9 as in the case of 2,3-dihydrofuran.
-C-0-C to 10CTL-1 and 1060CrrL-”
Absorption due to - was observed, and 1630CrrL-
It was found that the absorption due to the double bond of ' has disappeared.

In addition, from the nuclear magnetic resonance absorption spectrum, two absorptions occupying the same area on the spectogram can be seen at 1.9 ppm and 3.8 ppm, and the latter is associated with the protons of methine and methylene adjacent to oxygen, respectively. The former can be attributed to the other methine and methylene protons.

From these results, it was confirmed that this product was a polymer produced by polymerization proceeding through addition to double bonds.

The elemental analysis values of this polymer are C; 67.26%, H;
8.41%, value C calculated as a polymer of 2,3-dihydrofuran (C4H60); 68.59%,
H: 8.74%, which was almost the same.

The softening point was about 120°C.

All of these properties, ie, solubility in solvents, infrared absorption spectrum, nuclear magnetic resonance absorption spectrum, softening point, etc., agree with those of poly-2,3-dihydrofuran obtained by known methods.

This polymer was therefore identified as poly-2,3-dihydrofuran.

Example 2 Monomer isomerization polymerization of 2,5-dihydrofuran was carried out in the same manner as in Example 1 except that 0.01819 diethyl aluminum chloride was used instead of boron trifluoride etherate, and a white powder of 1.869 was obtained. I got it.

The conversion rate for the charged 2,5-dihydrofuran was 66
．． It was 9%.

The intrinsic viscosity measured in chloroform at 30°C is 0.
It was 25dt/'J.

The obtained white powder was prepared in the same manner as in Example 1 to prepare poly-2,3.
- It was confirmed that it was dihydrofuran.

Example 3 Tin tetrachloride was used instead of boron trifluoride etherate.
2 was carried out in the same manner as in Example 1 except that 0391g- was used.
, 5-dihydrofuran was subjected to monomer isomerization polymerization to obtain 1.559 of a white powder.

The conversion rate for the charged 2,5-dihydrofuran was 55
．． It was 7%.

In addition, the intrinsic viscosity measured at 30°C in chloroform is o,
15d, /, /9.

The obtained white powder was prepared in the same manner as in Example 1 to prepare poly2.3-
It was confirmed that it was dihydrofuran.

Example 4 Titanium tetrachloride instead of boron trifluoride etherate
．． Monomer isomerization polymerization of 2,5-dihydrofuran was carried out in the same manner as in Example 1 except that n-hebutane was used in place of benzene and white powder 1.
I got 599.

The conversion rate for the charged 2,5-dihydrofuran was 57
．． It was 2%.

In addition, the intrinsic viscosity measured at 30°C in chloroform is o,
25d, /, /l.

The obtained white powder was treated in the same manner as in Example 1 to prepare PoIJ-2,
It was confirmed that it was 3-dihydrofuran.

Example 5 A high-pressure mercury lamp (100 W manufactured by Riko Kagaku Sangyo Co., Ltd., UV
L-300P) was inserted and the inside of the reaction vessel was made into a nitrogen atmosphere, and then 230% of benzene and 0.2949% of iron pentacarbonyl were added. Boron trifluoride etherate 0.426
9 and 2,5-dihydrofuran were added sequentially for 250 minutes.

This reaction vessel was immersed in a low-flooding tank and irradiated with a high-pressure mercury lamp to carry out isomerization polymerization for 18 hours.

During the polymerization reaction, the polymerization temperature was maintained at 5° C. by adjusting the refrigerant filling degree.

After the reaction was completed, the product was separated in exactly the same manner as in Example 1 to obtain 210.59 of a white powder.

The conversion rate for the charged 2,5-dihydrofuran was 84
．． It was 2%.

This was identified in the same manner as in Example 1, and then subjected to high performance liquid chromatography (column G manufactured by Toyo Soda Kogyo Co., Ltd.).
3000H6, mobile phase tetrahydrofuran, detector UV
When measured at 254 nm), the degree of polymerization was 200 to 15.
PoIJ-2,3 with a wide molecular weight distribution over 00
- It was estimated that it was dihydrofuran.

Comparative Example 1 Example 1 except that boron trifluoride etherate was not added.
2,5-dihydrofuran was reacted in exactly the same manner.

The conversion rate to 2,3-dihydrofuran was measured by gas chromatography and was approximately 5%.

Moreover, no solid material was obtained by this reaction.

Comparative Example 2 Polymerization of 2,5-dihydrofuran was attempted in the same manner as in Example 1 except that iron pentacarbonyl was not added, but no solid material was obtained.

Claims (1)

[Claims] 1. A method characterized by subjecting 2,5-dihydrofuran to monomer isomerization polymerization in the presence of iron pentacarbonyl, a Friedel-Crafts type catalyst, and/or an alkyl metal compound under irradiation with light. A method for producing poly-2゜3-dihydrofuran. 2. The manufacturing method according to claim 1, wherein the light is ultraviolet light and/or visible light. 3. Claim 1 or 2, wherein the Friedel-Crafts type catalyst and/or the alkyl metal compound is boron trifluoride or its complex, tin tetrachloride, titanium tetrachloride, aluminum chloride, zinc chloride, or a mixture thereof. Manufacturing method described in section. 4. The production method according to claim 1 or 2, wherein the Friedel-Crafts type catalyst and/or the alkyl metal compound are diethylaluminum chloride, ethylaluminum dichloride, or ethylaluminum sesquichloride. 5. The production according to any one of claims 1 to 4, wherein the amount of iron pentacarbonyl used as a catalyst is 0.01 to 2% by weight based on the raw material 2,5-dihydrofuran. Method. 6. Any one of claims 1 to 5, wherein the amount of Friedel-Crafts type catalyst and/or alkyl metal compound used is 0.01 to 2% by weight based on the raw material 2,5-dihydrofuran. The manufacturing method described in the section. 7. The manufacturing method according to any one of claims 1 to 6, wherein the reaction is carried out in the presence of a solvent. 8. Claim 7, wherein the solvent is benzene, toluene, chlorobenzene, carbon tetrachloride, dichloroethane, chloromethane, trichloroethane, hexane, or heptane.
Manufacturing method described in section. 9. The manufacturing method according to claim 1 or 8, wherein the amount of the solvent used is about 9 to about 95% by volume of the total liquid volume of the reaction system. 10. The manufacturing method according to any one of claims 1 to 9, wherein the reaction is carried out at a temperature of about -90°C to about 60°C. 11. The manufacturing method according to any one of claims 1 to 10, wherein the reaction is carried out in an inert gas atmosphere.