JPS6291509A - Thermoreversibly hydrophilic and hydrophobic polymer and its production - Google Patents

Abstract

PURPOSE:To obtain the titled thermoreversible polymer which is soluble in water at low temperatures while insoluble in water at high temperatures and is suitable for temperature sensors, light-screening bodies, etc., by radical- polymerizing N-ethoxyethyl(meth)acrylamide. CONSTITUTION:The purpose thermoreversibly hydrophilic acid hydrophobic polymer of formula II (wherein n>=2) is obtained by radical-polymerizing N- ethoxyethyl(meth)acrylamide of formula I (wherein R1 is H or methyl). As a process for polymerizing this compound, a solution polymerization process is usually preferable, and one comprising dissolving the compound of formula I in a solvent (e.g., benzene) and irradiating the solution with a radiation or heating it in the presence of a radical polymerization initiator can be adopted, for example. The compound of formula I can be produced by, for example, reacting (meth)acryloyl chloride with 2-ethoxyethylamine and triethylamine in benzene.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel hydrophilic-hydrophobic thermoreversible polymer and a method for producing the same. In more detail, 9
The present invention relates to a light shielding body and a temperature sensor.

A hydrophilic-hydrophobic thermoreversible polymer that can be used in adsorbents, toys, interiors, printing agents, displays, separation membranes, mechanochemical device materials, etc.

The present invention also relates to a method for efficiently manufacturing the same.

Conventional technology Some water-soluble polymer compounds exhibit a special reversible dissolution behavior in which they precipitate and become cloudy above a certain temperature (transition temperature or cloud point) in an aqueous solution state, and dissolve and become transparent below that temperature. This is called a hydrophilic-hydrophobic thermoreversible polymer.

In recent years, it has been used as a light shield in greenhouses, chemical laboratories, radioisotope tracer laboratories, temperature sensors, and adsorbents for water-soluble organic substances.

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

Among these thermoreversible polymers, polyacrylamide derivatives are suitable for the above-mentioned uses because they are stable in water and can be produced at relatively low cost.

So far, poly(N-propylacrylamide), poly(N,N-diethylacrylamide), and poly(N-acrylpyrrolidine) have been thermoreversible.
, poly(N-acrylpiperidine), etc. are only known.

For this reason, even if we try to use polyacrylamide derivatives in things such as temperature sensors and light shielding materials, the transition temperature is unique to each substance and cannot be set arbitrarily. cannot escape being restricted.

Problems to be Solved by the Invention Under these circumstances, the purpose of the present invention is to develop novel polyacrylamide derivatives having different transition temperatures in order to expand the scope of use of crude hydrophobic and thermoreversible polyacrylamide derivatives. An object of the present invention is to provide a polyacrylamide-based hydrophilic-hydrophobic thermoreversible polymer and a method for efficiently producing the same.

Means to solve problems This is the result of extensive research by the inventors.

It was discovered that the above object could be achieved by a polymer obtained by radical polymerization of a vinyl compound represented by the general formula % (R1 in the formula is a hydrogen atom or a methyl group), and based on this knowledge, The present invention has now been completed.

In other words, the present invention is as follows.

Radical polymerization of a hydrophilic-hydrophobic thermoreversible polymer represented by the general formula % (Rt in the formula has the same meaning as above) and a vinyl compound represented by the general formula The present invention provides a manufacturing method.

The vinyl compound represented by the general formula m used in the present invention is preferably prepared at 0 to 10°C in acrylic acid chloride or methacrylic acid chloride, 2-ethoxyethylamine, and triethylaminetrabenzene, for example, as shown in the following formula. It can be produced by a method of reacting at a temperature of .

l (R1 in the formula has the same meaning as above) Specifically, the vinyl compound used in the present invention is:

N-ethoxyethyl acrylamide (boiling point 105'C/
3 mm Hg), and N-ethoxyethyl methacryl amide (congener'C/1 mm Hg).

In the present invention, these vinyl compounds are subjected to radical polymerization to produce the polymer. As for the polymerization method,
Although there are solution polymerization methods and bulk polymerization methods, the solution polymerization method is usually preferably used. In this solution polymerization method, the vinyl compound is dissolved in a solvent to form a solution having a concentration of 1 to 80% by weight, and any commonly known radical polymerization method can be used. There are no particular restrictions on the solvent used in such solution polymerization, but examples include water, alcohols, N,N-dimethylformamide, N,N-
Examples include dimethylacetamide, dimethylsulfoxide, acetone, dioxane, tetrahydrofuran, benzene, chloroform, carbon tetrachloride 3R, and each of these may be used alone or in combination of two or more.

The thus obtained polymer of the present invention has high-temperature hydrophobic type thermoreversibility, being soluble in water at low temperatures and insoluble in water at high temperatures. The transition temperature of the polymer varies depending on the polymerization conditions, but in a 1% by weight aqueous solution, it is 34-36°C for poly(N-ethoxyethyl acrylamide),
(N-ethoxyethyl methacrylamide) 44.0~
It is in the range of 46.0°C.

It can be identified by external radiation absorption spectrum. Regarding the degree of polymerization, the intrinsic viscosity [η] at a temperature of 30°C in methanol solution is 0°01 to 6.0.
is practical. Furthermore, regarding solubility in various solvents, cold water, methanol, ethanol, chloroform, and acetone.

Tetrahydrofuran, N,N-dimethylformamide,
It is soluble in ethyl acetate, etc., but insoluble in hot water, n-hexane, n-nihebutane, etc.

Effects of the Invention The polyacrylamide-based hydrophilic-hydrophobic thermoreversible polymer of the present invention has high-temperature hydrophobic thermoreversibility in that it reversibly dissolves in water at low temperatures and becomes insoluble in water at high temperatures. It has a transition temperature different from that of conventionally known thermoreversible polyacrylamide derivatives, making it suitable for use in greenhouses, chemical laboratories,
Light shielding materials such as radioisotope tracer laboratories,
Temperature sensors, adsorbents for water-soluble organic substances, and even toys.

Ru.

For example, if the polymer of the present invention is laminated on a transparent plate in the form of an aqueous solution or in the form of a hydrogel or microcapsule, it will automatically prevent the indoor temperature from increasing more than necessary due to direct sunlight. It is suitable as a light shielding body for

Example Next, the present invention will be explained in more detail with reference to Examples.

In the Erlenmeyer flask of Reference Example 11, 50.9 g of triethylamine, 2
-44.5 g of ethoxyethylamine and 450 g of benzene
1111 and cooled with ice to keep the content below 10°C, and while stirring, a mixed solution of 41.51 nl of acrylic acid chloride and 50 ml of acetone was slowly added dropwise from the dropping funnel over a period of about 3 hours. .9 After completion of dripping
The reaction solution was left to cool for a day and night, then filtered, and the filtrate was collected using a rotary evaporator to obtain 64.0 g of liquid material.
I got it.

From the mass spectrum and IR spectrum, this product is N-
It was confirmed to be ethoxyethyl acrylamide.

Similarly, N-ethoxyethyl methacrylamide was synthesized.

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

Using azobisisobutyronitrile as a polymerization initiator 2
At the 20 m mark of a methanol solution with a polymerization initiation degree of 50 [1] g/1 ml, add a predetermined weight of N-ethoxyethyl acrylamide or N-ethoxyethyl methacrylamide, place it in an ampoule, and decompress it under reduced pressure using liquid nitrogen. After airing, it was sealed and allowed to react at a temperature of 50°C for 21 hours in the former case and 48 hours in the latter case. Next, after adding acetone to the reaction solution, this solution was poured into a mixed solvent of benzene-n-beef sanitation and heated at 30°C using an Ubbelohde viscometer.
The viscosity was measured and the limiting viscosity [η] was determined. In addition, the transition temperature is calculated by the change in light transmittance due to the temperature change of the aqueous solution and the DS
It was determined from C measurement. That is, a polymer aqueous solution with a concentration of 1% by weight was prepared, set in a spectrophotometer with a temperature controller, and measured for light transmittance at a wavelength of 500 nm while increasing the temperature at a rate of 1 °C/min. The transition temperature is the point where this light transmittance is the initial transmittance and 6 temperatures (T) 1. Seek it. Maepo IJ? -7'~81TIg to water 50~60
mg, and 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 (Ta).

These results are shown in the table below. Further, FIG. 1 shows a transmittance-temperature curve, and FIG. 2 shows a DSC curve.

In these figures, (1) is data for poly(N-ethoxyethyl acrylamide), and f2) is data for poly(N-ethoxyethyl methacrylamide). The dotted line is data for the cooling cylinder i1.

to 1

[Brief explanation of drawings]

FIG. 1 is a graph showing a transmittance-temperature curve for a 1% by weight aqueous solution of the polymer of the present invention, and FIG. 2 is a graph. It is a graph which shows the DSC curve of this invention polymer aqueous solution.

Claims (1)

[Claims] 1 Hydrophilic-hydrophobic thermoreversible compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1 in the formula is a hydrogen atom or a methyl group, and n is an integer of 2 or more) type polymer. 2 General formula CH_2=CR_1-CONH-(CH_2)-OCH
_2CH_3 (R_1 in the formula is a hydrogen atom or a methyl group) The general formula is characterized by radical polymerization of a vinyl compound ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1 in the formula is the same as above) having the same meaning) A method for producing a hydrophilic-hydrophobic thermoreversible polymer.