JPS63241007A - Thermo-reversibly hydrophilic-hydrophobic material - Google Patents

Abstract

PURPOSE:To obtain the title material which turns hydrophobic at high temperatures and is useful for light screen, temperature sensor, separative membrane, mechanochemical element material, etc., by polymerizing a specified vinyl compound and dissolving the polymer in water. CONSTITUTION:(Meth)acryloyl chloride, 3-methoxypropylamine and triethylamine are reacted in a solvent such as acetone, benzene or toluene, pref. at 0-10 deg.C, to give a vinyl compound of formula I (where R1 is H or CH3). The product is dissolved in a solvent such as alcohol, N,N-dimethylformamide, etc., so that its concn. be 1-80wt.%, and the soln. is polymemrized by, e.g., heating in the presence of a radical polymn. initiator or applying light in the presence of a photosensitizer to give a thermo-reversibly hydrophilic-hydrophobic polymer consisting of recurring units of formula II and having an MW corresponding to an intrinsic viscosity of 0.01-6.0 (at 30 deg.C). This product is dissolved in water, so that its concn. be at least 0.01wt.%, to give an aq. soln. having a desired transition temp.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel woody-hydrophobic thermoreversible material. More specifically, the present invention relates to a hydrophilic-hydrophobic thermoreversible material that can be applied to light shields, temperature sensors, adsorbents, toys, interiors, textile printing agents, displays, separation membranes, mechanochemical device materials, etc. It is something.

Conventional technology Some water-soluble polymer compounds exhibit a special reversible dissolution behavior in which in an aqueous solution state, they precipitate and become cloudy above a certain temperature (transition temperature or raw point), and dissolve and become transparent below that temperature. This polymer is called a woody-hydrophobic thermoreversible polymer, and in recent years it has been used as a light-shielding material in greenhouses, chemical laboratories, Radioisosorb tracer laboratories, temperature sensors, and adsorption for water-soluble organic substances. It is being used as a medicine.

As such thermoreversible polymers, partially saponified polyvinyl acetate, polyvinyl methyl ether, methylcellulose, polyethylene oxide, polyvinylmethyloxacilidinone, polyacrylamide derivatives, and the like are conventionally known.

These Etzk-type polymer polyacrylamide derivatives are stable in water and can be produced at relatively low cost, so they are suitable for the above-mentioned uses. -isopropylacrylamide), poly(N, N-diethylacrylamide)
, poly(N-acrylpyrrolidine), etc. are only known.

For this reason, even if polyacrylamide derivatives are used in temperature sensors or light shielding materials, for example, the transition temperature is unique to the substance and cannot be set arbitrarily, and the limited number of derivatives available so far have limited the scope of use. cannot escape being restricted.

Problems to be Solved by the Invention Under these circumstances, the purpose of the present invention is to expand the scope of use of woody-hydrophobic thermoreversible polyacrylamide derivatives having different transition temperatures. The object of the present invention is to provide a novel polyacrylamide-based wood-philic-hydrophobic thermoreversible material.

Means for Solving the Problems As a result of intensive research, the inventors found that the general formula (R in the formula
1 is a hydrogen atom or a methyl group) A wood-philic-hydrophobic thermoreversible material consisting essentially of an aqueous solution of a polymer obtained by radical polymerization of a vinyl compound represented by the following formula can achieve the above object. The present invention was completed based on this finding.

That is, the present invention consists of a repeating unit represented by the general formula (R1 in the formula has the same meaning as above), and has an intrinsic viscosity [η)0 at 30'C.
．． The present invention provides a lignophilic-hydrophobic thermoreversible material consisting essentially of an aqueous solution of a lignophilic-hydrophobic thermoreversible polymer having a molecular weight corresponding to 0.01 to 6.0.

The vinyl compound represented by the general formula (1) used in the present invention is prepared by combining acrylic acid chloride or methacrylic acid chloride, 3-methoxypropylamine, and triethylamine with acetone, benzene, Alternatively, it can be produced by a method of reacting in toluene, preferably at a temperature of 0 to 10°C.

CI+, =CR+ (C2τ), ), N・11C1 group+
-(c+-+,)3-o-c+-+.

(R1 in the formula has the same meaning as above) Specifically, the vinyl compound used in the present invention includes N-methoxypropylacrylamide (boiling point 98°C/2mmHg), N-
Methoxypropyl methacrylamide (105℃/3m
mHg).

The polymer used in the present invention can be produced by radical polymerization of these vinyl compounds, including the zero polymerization method, the bulk polymerization method, and the bulk polymerization method, but the solution polymerization method is usually preferably used. In this polymerization method, the vinyl compound is dissolved in a solvent to form a solution with a concentration of 1 to 80% by weight, and then irradiated with radiation, heated in the presence of a radical polymerization initiator, or heated in the presence of a photosensitizer. Any commonly known radical polymerization method, such as light irradiation, can be used. There are no particular restrictions on the solvent used in such a solution polymerization method, but examples include water, alcohols, N,
-dimethylformamide, N, N-dimethylacetamide, dimethylformamide, acetone, dioxane,
Examples include tetrahydrofuran, benzene, chloroform, and carbon tetrachloride, and each of these may be used alone or in combination of two or more.

The polymer used in the present invention thus obtained has a high-temperature hydrophobic type thermoreversibility that dissolves in water at low temperatures and becomes insoluble in water at high temperatures. Thermoreversible materials must be prepared in the form of combinations of the above polymers with water. At this time, the amount of the aqueous solution varies widely depending on the purpose of use, but the necessary force to make it 0.01 weight % or more is usually in the range of 0.05 to 30 weight %. The transition temperature of the polymer aqueous solution varies depending on the polymerization conditions, but in a 1% by weight aqueous solution, it is 44 to 48 °C for poly(N-methoxypropylacrylamide) and 58 to 65 °C for poly(N-methoxypropyl methacrylamide). in range. The transition temperature is changed by adding a water-soluble substance, such as an electrolyte such as common salt, or a water-soluble organic substance such as methyl alcohol.

Since the polymer used in the present invention has -CONH- groups, -0-CH3 groups, -CH2-CR,- groups, it can be identified by infrared absorption spectra and the like. Regarding the degree of polymerization, the intrinsic viscosity [η] at a temperature of 30°C in methanol solution is 0. It is in the range of O1 to 6.0. Furthermore, regarding solubility in various solvents, cold water, methanol, ethanol, chloroform, acetone,
It is soluble in tetrahydrofuran, N,N-dimethylformamide, etc., but insoluble in hot water, n-hexane, n-hebutane, etc.

Effects of the Invention The polyacrylamide-based wood-philic-hydrophobic thermoreversible material of the present invention has high-temperature hydrophobic thermoreversibility in that it dissolves in water at low temperatures and becomes insoluble in water at high temperatures. It has a transition temperature different from that of thermoreversible polyacrylamide derivatives, which are used in greenhouses, chemical laboratories, radioisotope tracers, light shields in laboratories, temperature sensors, and adsorbents for water-soluble organic substances. Furthermore, it can be applied to toys, interior decoration, textile printing agents, displays, separation membranes, mechanochemical device materials, etc.

EXAMPLES Next, the present invention will be explained in more detail by reference examples and examples.

Reference example 1 L Erlenmeyer flask and 50.9 g of triethylamine.

3-methoxypropylamine 51.6g and acetone 4
Add 50 ml of acrylic acid chloride and 50 ml of acetone to this mixture and cool with ice to keep the content below 10°C, while stirring] Slowly drop a mixed solution of 41.5 ml of acrylic acid chloride and 50 ml of acetone into the mixture from the dropping funnel over a period of about 3 hours. After the addition of 1 drop was completed, the reaction solution was left to cool for a day and night, then filtered, and acetone was removed from the filtrate using a low evaporator and concentrated.Then, it was distilled under reduced pressure to obtain a colorless and transparent fraction with a boiling point of 98°C/2mmHg. was collected to obtain 54.4 g of a liquid substance.

This one is a mass spectrum and an IR spectrum;
- Confirmed to be methoxypropylacrylamide. N-methoxypropylmethacrylamide was synthesized in the same manner.

Examples Radical polymers of various monomers obtained in Reference Examples were produced.

Using azobisisobutyronitrile as a polymerization initiator,
Methanol solution 20 with polymerization initiator concentration 50mg/1ml
A predetermined weight of monomer was added to the monomer, which was then sealed and reacted at a temperature of 60°C for 51 hours.Next, acetone was added to the reaction solution, and this solution was poured into a benzene-n-hexane mixed solvent to prepare a polymer. was precipitated and collected.

The obtained polymer was made into a methanol solution, and the viscosity was measured at 30° C. using an Ubbelohde viscometer to determine the intrinsic viscosity [η]. In addition, the transition temperature was determined from the change in light transmittance accompanying the temperature change of the aqueous solution and from DSC measurements. That is, a polymer aqueous solution with a concentration of 1% by weight was prepared, set in a spectrometer equipped with a temperature controller, and heated at a heating rate of 1°C/min.
The light transmittance at a wavelength of 500 nm was measured while raising the temperature at 500 nm, and the transition temperature was determined from the temperature (TL) at which the light transmittance became 1/2 of the initial transmittance. Also, 7-8 mg of polymer
was added to 50 to 60 mg of water, DSC measurement was performed at a heating rate of 1° C./min, and the transition temperature was also determined from the temperature at the top of the endothermic peak (T6).

These results are shown in the table below. Figures 1 and 2 show the transmittance-temperature curves, and Figures 3 and 4 show the L7 rIQ (
' dhtJl t-rreS In these figures, (
1) is poly-(N-methoxypropylacrylamide)
, (2) are data for poly(N-methoxypropylmethacrylamide), and in FIGS. 1 and 2, the solid line is the data when the temperature is raised, and the dotted line is the data when the temperature is lowered.

As can be seen from the above table, aqueous solutions of poly(N-methoxypropylacrylamide) and poly(N-methoxypropylmethacrylamide) are thermoreversible.

[Brief explanation of the drawing]

Figures 1 and 2 are graphs showing the transmittance-temperature curve for a 1mi% aqueous solution of the polymer used in the present invention, and Figures 3 and 4 are DSC graphs of the aqueous solution of the polymer used in the present invention.
It is a graph showing a curve. Figure 1 Temperature (C) Figure 2 Temperature (C) Figure 3 Temperature (C) Figure 4 Temperature (°C)

Claims (1)

[Claims] 1 Consists of repeating units represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R_1 in the formula is a hydrogen atom or methyl group), and has an intrinsic viscosity at 30°C [
η] A hydrophilic-hydrophobic thermoreversible material consisting essentially of an aqueous solution of a hydrophilic-hydrophobic thermoreversible polymer having a molecular weight corresponding to 0.01 to 6.0.