KR101949610B1 - Polydimethylsiloxane using aziridine and method for preparing the same - Google Patents

Abstract

The present invention relates to polydimethylsiloxane polymers using aziridine and a process for their preparation.

Description

(Polydimethylsiloxane using aziridine and a method for preparing the same)

The present invention provides a polydimethylsiloxane polymer using aziridine as a ternary cyclic compound and a method for producing the same.

The increasing complexity of the technology to address health, energy and environmental issues is increasing the demand for materials with tailored characteristics at the molecular level. Such a material can be prepared by incorporating a clickable moiety (moiety capable of binding other functional groups) into the substrate in a simple and high yield. Thus, the technology to build tailor-made materials with organic cyclic compounds with ring modifications has received attention for decades. Organic ring compounds on the surface and / or surface of the material enable additional chemical reactions through their ring opening reactions and can induce structural modifications of various types of biological or non-biological substrates for individual applications.

Ternary O-heterocyclic epoxides have received particular attention in the development of functional polymer materials. The delicate ring structure of the epoxide can be easily opened in the presence of the nucleophile. This feature has been actively utilized in many categories of polymeric materials development including adhesives, surface coatings, self-healing materials, and matrices for making nanomachic-sized materials. However, there is a problem that the epoxide is promoted by moisture and a ring opening reaction occurs.

The ring opening reaction of the epoxide is typically dependent on the amine-based nucleophile. Aziridine is a 3-membered N-heterocyclic compound that is structurally similar to an epoxide, but has greatly different chemical properties. The chemical and position selectivity of aziridine for the ring opening reaction is programmable by controlling the steric hindrance of the electron structure and the substituents on the nitrogen of the two sp 3 carbons and aziridine. In addition, aziridines can be structurally and robustly designed in ambient conditions, including harsh conditions, such as high temperature and acid / basic conditions. Despite the long history of using aziridines in organic synthesis, little has been done with aziridine in the field of materials science.

The inventors of the present invention especially focused on polydimethylsiloxane as a support for the polymer scaffold for this study. PDMS is widely used in technologies requiring an organic polymer because it is optically transparent, stretchable, inexpensive, commercially available, and non-toxic. Because of these unique properties, PDMS can be applied to flexible displays and electronics or lab-on-a-chip. As the demand for the realization of complicated technology using PDMS increases, much efforts are being made to develop PDMS analogs having fine chemical properties at the molecular level. The general strategy is to use post-reforming of the PDMS surface using oxygen / ultraviolet treatment, chemical click reactions and mixing nanometer-sized particles into the PDMS. PDMS analogs formed through this strategy often suffer from the loss of original optical and / or elastomeric properties. Another strategy is the synthesis of novel siloxane monomers with functional groups and the production of PDMS derivatives with desired functionality based on these polymers. This strategy allows the PDMS structure to be designed at the molecular level and allows the composition and structure to be relatively uniform over the sample. Although multiple click residues such as azide and thiol have been incorporated into PDMS by polymerizing siloxane monomers containing these moieties, it has been difficult to represent a wide range of substrates, as well as clickable PDMS based on simple, efficient, direct click reactions.

Patent Document 1: Korean Patent Publication No. 10-2006-0003749 Patent Document 2: Korean Patent No. 10-16314781

An object of the present invention is to provide a polydimethylsiloxane polymer using aziridine as a ternary ring compound.

Another object of the present invention is to provide a process for preparing a polydimethylsiloxane polymer using the aziridine.

In order to achieve the above object, the present invention provides a polymer represented by the following formula (1).

[Chemical Formula 1]

In the above formula (1)

a is an integer of 1 to 20,

b is an integer of 0 to 20,

c is an integer of 1 to 20,

l is an integer of 1 to 20,

m is an integer of 1 to 20;

According to the present invention, the polymer of formula (1) may be reacted with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group so that an aziridine group can be opened, and the above-mentioned aziridine moiety Or a compound containing a thiol group is attached.

According to the present invention, the polymer of formula (1) may have elasticity.

The present invention also relates to a process for producing a compound represented by the following formula (2), a compound represented by the following formula (3) and a compound represented by the following formula (4) under a karstedt catalyst, 1], comprising the steps of: (a) preparing a polymer having an aziridine group,

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 1]

In the above Chemical Formulas 1 to 4,

a is an integer of 1 to 20,

b is an integer of 0 to 20,

c is an integer of 1 to 20,

l is an integer of 1 to 20,

m is an integer of 1 to 20,

n is an integer from 2 to 30,

a + b + c = n.

According to the present invention, the reaction may be carried out at 50 to 100 ° C for 0.5 to 3 hours.

According to the present invention, the compound of Formula 4 can be prepared by reacting (1-benzylaziridin-2-yl) methanol with chlorodimethyl (vinyl) silane at 40 to 80 ° C.

According to the present invention, the (1-benzylaziridin-2-yl)

Ethyl 2,3-dibromopropanoate is reacted with benzylamine in the presence of a base such as triethylamine to produce ethyl 1-benzyl aziridine-2-carboxylate; And reacting the ethyl 1-benzyl aziridine-2-carboxylate with lithium aluminum hydride.

According to the present invention, the above reaction is carried out in the presence of 0.5 to 2 parts by weight of the compound represented by the above-mentioned formula (3) and 0.02 to 0.2 part by weight of the compound represented by the above formula (4), based on 10 parts by weight of the compound represented by the above formula By weight.

According to the present invention, there can be further carried out a step of ring-opening an aziridine group of the formula (I) by reacting a compound represented by the formula (I) with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group .

The manufacturing method according to the present invention can be used for the manufacture of customized PDMS. The process for producing clickable PDMS (aziPDMS) according to the present invention can be made using a simple, general PDMS curing process without compromising the ring structure of the aziridine. In addition, the orthogonal ring opening reaction of aziridine according to the present invention is effective for post-modification of a polymer scaffold (PDMS) having a wide substrate range. Post-modification of the PDMS through the ring opening reaction of aziridine according to the present invention is not limited to the surface, but may be performed in the inner cavity or in a region-specific manner. Further, the programmable reactivity and chemical selectivity of aziridine can be used to design advanced materials that respond to the desired reaction conditions.

The present inventors have found that PDMS (aziPDMS) comprising an aziridine linked by a covalent bond can be modified by orthogonal ring opening reaction of an aziridine with a carboxylic acid, alcohol, amine or thiol. This post-modification has established the characteristics of aziPDMS ring opened by using photoluminescent and fluorinated molecules on macroscopic and molecular scale, respectively, via ultraviolet irradiation and XPS specification. The amount inside the PDMS scaffold is directly adjustable. The customized PDMS according to the present invention and its manufacturing method are unprecedentedly attractive and efficient, and require a molecularly controlled function such as a flexible display, a nano ink pen, a biomedical sensor chip, an optical material and a contact charging surface Can be usefully applied to construct functional materials and devices.

1A is a structure of a compound used to prepare a polydimethylsiloxane polymer containing aziridine according to the present invention. FIG. 1B is a graph showing the preparation of a polydimethylsiloxane-based polymer (aziPDMS) containing aziridine and post-reforming through a ring-opening reaction. 1C is a photograph of the film of Comparative Example 1 (PDMS) and Example 1.6 (aziPDMS) according to the present invention (left) and a static contact angle image of water droplets (right). FIG. 1D is a scanning scan result of PDMS (gray line, control group) and aziPDMS (black line) obtained by X-ray photoelectron spectroscopy (XPS). FIG. 1E shows the XPS depth profile obtained through in situ etching of aziPDMS.
Figure 2A shows the results of a comparison of the fluorescence intensity of the UV light of Example 1 (PDMS) and that of the Example 1.6 (aziPDMS) film in a 2.5 mM 5 (6) carboxyfluoscein solution. ). The aziPDMS emitted a significant amount of fluorescence, but the PDMS emitted little fluorescence. FIG. 2B is an intensity-elongation curve of the PDMS and aziPDMS fibers before and after the ring-opening reaction with the carboxylic acid compound (5 (6) -carboxyfluoscein). Figure 2c shows the results of images of the open aziPDMS fiber of the present invention at different elongation ratios. FIG. 2d shows the results of the PDMS / aziPDMS laminate structure, followed by post-modification with 5 (5) -carboxyfluoscein. lt; RTI ID = 0.0 > aziPDMS < / RTI >
Figure 3a is an image of aziPDMS containing different amounts of aziridine (base: hardener: aziridine 1 = 10: 1: x where vinyl is terminal, where x is 0 to 0.15). Figure 3b is the UV absorption spectrum of the azi PDMS film. As the content of aziridine increased, the absorption intensity increased. FIG. 3c is a photograph of the aziPDMS film taken after performing the ring-opening reaction by culturing in 2.5 mM 5 (6) -carboxyfluorescein. Figure 3d shows the photoluminescence emission spectrum results of ring-opening aziPDMS films. Figure 3e is a measurement of the substrate range of aziPDMS via XPS measurement, which is the result of incorporation of various fluorinated carboxylic acids, alcohols, amines and thiol derivatives into aziPDMS via an aziridine ring opening reaction. The inserted graph shows the high resolution spectral results of the F1s region for PDMS (control group) and open aziPDMS.
Figure 4a identifies the structural specificity (surface versus interior) of aziPDMS by post-modification by controlling the polarity of the solution for low-wetting PDMS. The aziPDMS cube (1 cm x 1 cm x 1 cm) was mixed with 0.25 mM 5 (6) -carboxyfluorescein solution (yellow CHCl ₃ : MeOH = 1: 5, v / v) and 0.25 mM 7- The image obtained by continuously irradiating a sample obtained by continuously culturing and dividing into hydroxy coumarin (blue; HCl ₃ : MeOH = 5: 1, v / v) was irradiated with visible light and ultraviolet light. FIG. 4B shows the result of confirming the post-modification surface depth of aziPDMS according to the polarity of the solution. As the amount of methanol decreased, the surface depth increased after the first reform (yellow region). 4C is a plot of percent surface depth as a function of volume of methanol in solution (defined as the ratio of the first post-reform surface depth to the half width of the total film).
Figure 5 is a schematic representation of the reaction scheme of Pt (0) -catalyzed hydrosilylation between aziridine 1 having a vinyl group at the end and a PDMS prepolymer.
Figure 6 shows the results of ¹ H NMR spectroscopy of Pt (0) -catalyzed hydrosilylation and ring opening reaction of aziridine and benzoic acid between silylhydride (Hardener B) and aziridine (1) with a vinyl group at the end . Curing agent B, a commercially available reagent, can be added with a small amount of an additive, and thus a peak can be detected.
Figure 7 shows the photoluminescence spectra of aziPDMS cultured in 5 (6) -carboxyfluorescein (red) and 2.5 mM 5 (6) -carboxyfluorescein (black) solutions in methanol.
FIG. 8 is a result of applying the thresholding technique for the cut aziPDMS film in FIG. 4B.

The present inventors have completed the present invention by developing a method of introducing aziridine on a molecular substrate and using a ring-opening reaction of aziridine in order to design a customized polymer scaffold at a molecular level. Specifically, the present invention provides a customized PDMS (hereinafter aziPDMS) prepared by curing a conventional PDMS prepolymer (Sylgard 184 Silicone elastomer kit) in the presence of aziridine having a terminal vinyl and a method for producing the same .

Hereinafter, the present invention will be described in more detail.

The present invention provides a polymer represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

a is an integer of 1 to 20,

b is an integer of 0 to 20,

c is an integer of 1 to 20,

l is an integer of 1 to 20,

m is an integer of 1 to 20;

In the present invention, the polymer of formula (1) may be reacted with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group to cause an aziridine group to be opened, and the above-mentioned aziridine group may be substituted with a carboxylic acid, Or a compound containing a thiol group is attached.

According to the present invention, the polymer of formula (1) has elasticity and can be easily stretched up to 250%.

According to the present invention, the polymer of formula (1) has improved lightweight and mechanical elasticity without loss of optical and mechanical properties as compared with conventional PDMS.

In addition, aziridine-functionalized PDMS (aziPDMS) according to the present invention can be easily synthesized from a prepolymer which is easily available.

The present invention relates to a process for preparing a compound represented by the following formula (1), which comprises reacting a compound represented by the following formula (2), a compound represented by the following formula (3) and a compound represented by the following formula (4) under a karstedt ' To produce a polymer represented by the general formula (1): < EMI ID = 1.0 >

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 1]

In the above Chemical Formulas 1 to 4,

a is an integer of 1 to 20,

b is an integer of 0 to 20,

c is an integer of 1 to 20,

l is an integer of 1 to 20,

m is an integer of 1 to 20,

n is an integer from 2 to 30,

a + b + c = n.

According to the present invention, the reaction may be a thermal curing reaction performed at 50 to 100 ° C for 0.5 to 3 hours.

According to the present invention, the compound of Formula 4 may be prepared by reacting (1-benzylaziridin-2-yl) methanol with chlorodimethyl (vinyl) silane at 40 to 80 ° C, In the presence of an organic solvent. The base may be triethylamine, but is not limited thereto. The organic solvent may be an organic solvent selected from methylene chloride, tetrahydrofuran, N, N-dimethylformamide, dimethylsulfoxide, toluene, ethanol, methanol, ethyl acetate and ether, Lt; / RTI >

According to the present invention, the above (1-benzylaziridin-2-yl) methanol is obtained by reacting ethyl 2,3-dibromopropanoate with benzylamine in the presence of a nitrogen stream and a base such as triethylamine to obtain ethyl 1 - benzyl aziridine-2-carboxylate; And reacting the ethyl 1-benzyl aziridine-2-carboxylate with lithium aluminum hydride.

According to the present invention, 0.5 to 2 parts by weight of the compound represented by the formula (3) and 0.02 to 0.2 part by weight of the compound represented by the formula (4) are reacted with 10 parts by weight of the compound represented by the formula It can be done. If the content of the compound represented by the formula (4) is less than the above range, the amount of the clickable part is too small to be easily reformed, and it is difficult to exhibit stretchability. On the other hand, if it exceeds the above range, serious interference occurs in cross-linking between the base and the curing agent, and transparency is lost, and an opaque polymer powder or oil is produced.

The compound represented by the formula (1) according to the present invention may be further reacted with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group to ring the aziridine group of the formula (1) A compound containing a carboxylic acid, an alcohol, an amine group or a thiol group may be attached to a ring-opened moiety of aziridine.

The present invention has the following three characteristics.

i) The manufacture of clickable PDMS can be made using conventional PDMS curing processes simply without compromising the ring structure of the aziridine.

2) Post-modification of PDMS is not limited to the surface but is possible inside the pores through ring-opening reaction of aziridine.

3) Using programmable reactivity, chemical selectivity, and a broad substrate range of aziridine, aziridine-based materials can be designed that respond to desired reaction conditions.

In the present invention, the molecular substrate may be polydimethylsiloxane (PDMS).

According to the present invention, PDMS containing aziridine can be prepared by thermally curing the prepolymer in the presence of aziridine at the terminal vinyl. The prepolymer may be such that the base (part A) and the curing agent (part B) are contained in a weight ratio of 8: 1 to 20: 1, preferably 10: 1 by weight Lt; / RTI >

According to the present invention, the thermosetting may be performed at 80 ° C for 2 hours, thereby obtaining a compound (aziPDMS) converted to PDMS having a covalently bonded aziridine pendant. The aziPDMS thus obtained may have optical transparency and mechanical elasticity retained by the conventional PDMS.

 Post-modification of aziPDMS can be accomplished through orthogonal ring opening reactions of the aziridine pendant (Fig. 1b). According to the present invention, alcohols, amines, thiols and carboxylic acids can be used for post-modification of aziPDMS.

The manufacturing process and the structural modification reaction according to the present invention are simple and effective, and can be carried out using commercially available reagents. Along with these advantages, the wide and robust ring opening reaction of aziridine is useful for preparing tailor-made polymeric materials.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims. In the following Examples and Comparative Examples, "% " and " part " representing the content are based on weight unless otherwise specified.

<Examples>

<Reagent>

Unless otherwise stated, all reagents were purchased from commercial sources. Organic solvents were purchased from DAEJUNG, KOREA and the water was purified using Aqua MAX-Basic System (deionized water, electrical resistivity of ~ 18.2 MΩ · cm). The Sylgard 184 elastoemr kit from Dow Corning was used.

<Device>

^{The 1} H and ¹³ C NMR spectra were measured with Bruker FT-NMR Advance-500 using CDCl ₃ as the solvent and residual solvent as the internal standard. The chemical shifts are expressed in ppm relative to the internal TMS and the coupling constant (J) is Herz. MS (ESI-QTOF) measurements were measured with Bruker compat Q-TOF MS. All XPS measurements were performed on a Thermo Scientific K-Alpha XPS instrument with a monochromatic Al K _alpha source. The UV-vis spectra were measured using an Agilent Technologies-Agilent 8453 UV-Vis spectrometer. For UV-vis absorbance measurements, an intact PDMS film was used as a blank. The film thickness of the sample was kept constant (~ 2 mm). The thickness of the sample necessarily produces an error at the microscopic level, but does not affect the overall tendency of λ _max as a function of the mass ratio of aziridine. The light emission spectrum was measured using a Hitachi F-7000 fluorescence spectrophotometer. The tensile strengths of PDMS and aziPDMS were measured using a Universal Testing Machine (UTM; WL 2100).

Synthesis Example 1 Synthesis of 1-benzyl-2 - (((dimethyl) (vinyl) silyl) oxy) -methyl) aziridine (1)

[Reaction Scheme 1]

Synthetic example  1.1. Ethyl 2,3- Dibromofropanoate

Ethyl acetate (16.3 mL, 150 mmol) was added to 75 mL of dichloromethane and bromine (7.7 mL, 150 mmol) was slowly added over 20 minutes under an inert atmosphere at 0 ° C. The reaction mixture was reacted at 0 ° C for 1 hour and then at room temperature for 3 hours. After completion of the reaction, the reaction mixture was added with a saturated solution of Na ₂ S ₂ O ₃ to terminate the reaction, followed by extraction with dichloromethane and water, and the desired compound was obtained from the organic layer. The analytical results of the obtained compound were consistent with data values known in the art. Yield 97% (37.6 g)

Synthetic example  1.2. Ethyl 1- Benzyl aziridine -2- Carboxylate

Benzylamine (3.4 mL, 30.8 mmol) was dissolved in 60 mL of anhydrous ethanol at 0 ° C in a nitrogen stream. To the solution was added the compound of Synthesis 1.1 (8 g, 30.8 mmol) and trimethylamine (8.5 mL, 69.6 mmol) , The temperature was raised to 60 占 폚, and the reaction was carried out for 1 hour. After completion of the reaction, the solvent was removed, and extraction was performed using dichloromethane and water. The organic layer was dried with a drying agent (magnesium sulfate), and then distilled under reduced pressure. The concentrated mixture was purified by column chromatography to give the desired compound as a white solid. The analytical results of the obtained compound were consistent with data values known in the art. Yield 80% (6.2 g)

Synthetic example  1.3. (One- Benzyl aziridine Yl) methanol

After dissolving the compound of Synthesis Example 1.2 (6.2 g, 30.2 mmol) in 130 ml of diethyl ether, lithium aluminum hydride (2.29 g, 60.4 mmol) was added slowly and stirred at room temperature for 3 hours. After completion of the reaction, water (2.3 mL) was added to quenched, 15% aqueous NaOH solution (2.3 mL) and water (6.9 mL) were added and the mixture was then filtered. After extracting the reaction mixture with ethyl acetate, the organic layer was dried with a drying agent and the solvent was removed under reduced pressure to obtain the desired compound in the form of a yellow powder. The analytical results of the obtained compound were consistent with data values known in the art. Yield 87% (4.31 g)

Synthetic example  1.4. Benzyl-2 - ((( Dimethyl (vinyl) silyl ) Oxy ) methyl ) Aziridin (1)

(5.5 g, 33.7 mmol) and triethylamine (5.0 mL, 36.1 mmol) were added to 50 mL of toluene distilled at room temperature under a nitrogen stream, and then chlorodimethyl (vinyl) silane (5.1 mL, 35.4 mmol ) Was slowly added. The reaction mixture was heated to 60 DEG C and allowed to react with the plate, and then extracted three times with ethyl acetate. The extracted ethyl acetate was mixed and then washed with distilled water. The water remaining in ethyl acetate was removed with anhydrous sodium sulfate and distilled under reduced pressure to obtain the desired compound in the form of a yellow oil. Yield: 92%) (7.7 g)

^{1 H NMR (500 MHz, CDCl} 3) δ 7.21 - 7.40 (m, 5H), 6.05 - 6.16 (m, 1H), 5.97 - 6.05 (m, 1H), 5.75 (dd, J = 20.1, 4.0 Hz, 1H ), 3.62 (dd, J = 11.1, 5.6 Hz, 1H), 3.53 (dd, J = 11.1, 5.6 Hz, 1H), 3.45 (s, 2H), 1.72-1.82 1H), 1.45 (d, J = 6.1 Hz, 1H), 0.18 (s, 6H);

^{13 C NMR (126 MHz, CDCl} 3) δ 139.1, 137.2, 133.3, 128.3, 129.9, 65.3, 64.3, 40.5, 31.2, -2.2, -2.3;

MS (ESI) m / z: [M + H] + calcd for C 14 H 22 NOSi: 248.1465; found: 248.1429.

Comparative Example  One. PDMS Manufacturing

A Sylgard 184 (Dow Corning) silicone elastomer kit containing a base and a curing agent was used. Specifically, a base and a curing agent are mixed at a weight ratio of 10: 1, and the mixture is allowed to stand under reduced pressure for 2 hours to form an inner bubble Followed by curing at 80 ° C for 2 hours.

Example  One. Preparation of aziPDMS

The aziPDMS was prepared using the known PDMS preparation method. AziPDMS was prepared by mixing base (A), a curing agent (B) and an aziridine (1) having a vinyl group at the terminal thereof, and Sylgard 184 was used as a model elastomer. Specifically, 1-benzyl-2 - (((dimethyl) (vinyl) silyl) oxy) methyl) aziridine was poured into a polytetrafluoroethylene (PTFE) mold and a mixture of a base and a curing agent was added to remove the entrapped air bubbles Degassed in a vacuum desiccator for 20 minutes. The mixture was thermally cured at &lt; RTI ID = 0.0 &gt; 80 C &lt; / RTI &gt; for 2 hours to produce an azi PDMS film.

At this time, the base: the hardener: 1-benzyl-2 - ((dimethyl (vinyl) silyl) oxy) methyl) aziridine was mixed in a weight ratio of 10: 1: X and X was contained in a range of 0.025 to 0.2 weight ratio. When X is larger than 0.2, crosslinking between the base and the curing agent is seriously interfered by aziridine having a vinyl group at a large amount of terminals, and powdery or oily opaque PDMS is produced, which is not preferable.

Example 1.1

AziPDMS with X = 0.025

Example 1.2

AziPDMS with X = 0.05

Example 1.3

AziPDMS with X = 0.1

Example 1.4

AziPDMS with X = 0.125

Example 1.5

AziPDMS with X = 0.15

Example 1.6

AziPDMS with X = 0.2

Example  2. Opening with Carboxylic Acid aziPDMS Manufacturing

AziPDMS films with different amounts of aziridine were placed in 2.5 mM 5 (6) -carboxyfluorescein solution (methanol: CH ₂ Cl ₂ = 1: 1; v / v) and incubated at room temperature for 18 hours 12 hours at slightly elevated temperature). Next, unreacted 5 (6) -carboxyfluorescein was removed by washing with methanol and CH ₂ Cl ₂ , and then dried under a high-temperature oven and vacuum.

Example  3. Fluorinated carboxylic acids, phenols, Thiophenol  And amine derivatives aziPDMS Manufacturing

(Trifluoromethyl) benzoic acid as the fluorinated carboxylic acid, 2,3,4,5,6-pentafluorophenol as the phenol, 2,3,4,5,6 as the thiophenol - pentafluorobenzenethiol was used. The aziPDMS film was post-modified with a variety of fluorinated nucleophiles in a manner similar to that of Preparation 3 using 5 (6) -carboxyfluorescein. The aziPDMS was incubated in a 20 mM THF solution of each fluorinated compound. For the amine derivative (4-trifluoromethylaniline), Lewis acid (10 mM of BF ₃ .OEt ₂ ) was added for post-reforming. Post-modification of aziPDMS to amines with Lewis acid is due to reduced nucleophilicity of the amine by fluorination.

Test Example 1. Reaction determination of silylhydride polymer (B in FIG. 1A: curing agent) with aziridine having a vinyl group at the terminal and verification of ring opening reaction with benzoic acid using ¹ H NMR:

As shown in Fig. 5, the thermosetting process of the PDMS prepolymer is the basis for the hydrosilylation by the Pt (0) catalyst between the silylhydride and the vinyl derivative.

As shown in FIG. 1A, in order to confirm whether the vinyl group of Compound 1 (aziridine having a vinyl group at the terminal) bonds with the silyl hydride in the presence of the Pt catalyst, Pt catalyst (Karstedt's catalyst, 1 mg, B (600 mg) was added to Compound 1 (120 mg, 0.48 mmol) in the presence of a base (0.001 mmol, 0.001 mmol) and the mixture was stirred at 80 ° C for 1.5 hours. ¹ H NMR spectrum of the mixture was measured to confirm the reaction.

The black ¹ H NMR spectrum at the bottom of Figure 6 is the result of the starting mixture and the red ¹ H NMR spectrum at the top is the result after 1.5 hours of reaction. As shown in Fig. 6, the hydrosilylation reaction between compounds 1 and B was confirmed through ¹ H NMR spectrum. The chemical shifts of 5.75, 6.01 and 6.10 ppm, corresponding to the vinyl protons of Compound 1, completely disappeared within 1.5 hours, confirming that the desired coupling reaction was very efficient. The aziridine ring structure was also maintained after the reaction, confirming that the chemical shifts corresponding to the aziridine residues (1.45, 1.69 and 1.77 ppm) remained unchanged.

Next, it was confirmed that the covalently bonded aziridine was able to carry out an effective ring-opening reaction with the carboxylic acid derivative. Experiments were carried out using a structurally simple compound, benzoic acid. Benzoic acid (67.0 mg, 0.55 mmol) in dichloromethane (3 ml) was added to the aziridine functionalized prepolymer at room temperature for 13 hours. ^{The 1} H NMR confirmed that the ring opening reaction of aziridine completely abolished the chemical shifts at 1.45, 1.69 and 1.77 ppm corresponding to the protons of the covalently bound aziridine, indicating that the desired ring opening reaction was quantitatively completed.

Test Example 2. X-ray photoelectron spectroscopy (XPS) analysis:

As shown in Fig. 1C, the apparent optical transparency of the aziPDMS of Example 1 and the PDMS of Comparative Example 1 was not distinguished. The surface wettability of the aziPDMS of Example 1 and the PDMS of Comparative Example 1 were similar ([Delta] [theta] = 6 [deg.]).

For the structural analysis using XPS, aziPDMS was immersed in impurity-free hexane and dichloromethane for 6 hours, respectively, and rinsed. (~ 102 eV) and O1s (~ 532 eV) signals corresponding to the PDMS backbone in the scan of azi PDMS, and C1s (~ 284 eV) and N1s (~ 284 eV) corresponding to the aziridine pendant ~ 398 eV) signal appeared. As shown in Table 1, both the calculated value and the atomic concentration (atomic%) of the experimental values in PDMS and aziPDMS were in agreement.

Depth profile XPD scans were performed by etching the aziPDMS surface (etch rate: ~ 5 nm / min). The depth profile of aziPDMS showed the highest atomic% of Si and O and the lowest atomic% c during the etching. Interestingly, the atomic% of N1s of aziPDMS was constant during the measurement, which means that aziridine is equally present on the surface and inside.

contents
atom% Si C O N
PDMS calcd ^b 25.0 50.0 25.0 0.0 exptl ^c 29.4 43.9 26.7 0.0 aZiPDMS ^a
calcd ^d 24.6 50.7 24.6 0.1 exptl ^c 27.3 47.6 24.6 0.5

a. Base: Hardener: Aziridine (1) at a terminal vinyl ratio of 10: 1: 0.2

b. Atomic% is calculated using (SiOC ₂ ) as the recurring unit.

c. Result data is average value measured 3 times

d. The molecular weight (Mw) of the siloxane repeating unit with or without the aziridine pendant is 74

Test Example 3. Red shift of? _Max in the photoluminescence spectrum of ring-opened aziPDMS by 5 (6) -carboxylic fluorosine:

Surface depth was determined by image analysis using the threshold method. To determine the surface depth of the post-modification, aziPDMS was functionalized using two different photoluminescent ring-opening reagents in polar and nonpolar solutions. A photoluminescent image of the multifunctional aziPDMS film was obtained and the image was converted into a grayscale image using software (ImageJ) and the image was analyzed on the basis of a single intensity value using the grayscale image. The gray level intensity at each pixel was calculated as the average of the color values for the red, green, and blue portions in the color image. A binary (black and white) image was generated from grayscale images by applying a maximum entropy threshold. Using this method, all image pixels can be classified into foreground (regions where the aziridine of the present invention is open by 5 (6) -carboxyfluorescene) or background pixels. The percentage of the surface depth after the first post-reform was determined by determining the ratio of the width of white pixels (corresponding to post-surface modification) to half the width of the film in the line and averaging from each of the 10 or more samples.

Post-modification of aziPDMS via ring opening of aziridine was first carried out with carboxylic acid derivatives. Aziridine having an electron donating substituent (benzyl N-substituent of the present invention) was subjected to ring-opening reaction with a catalyst and an additive-free carboxylic acid under a nitrogen atmosphere at a relatively high temperature such as an ambient temperature or 50 ° C.

The acidic proton of the carboxylic acid reacts with the lone electron pair of the nitrogen atom of the aziridine. This reaction produces an activated aziridinium structure, followed by subsequent addition of the carboxylate. The ring opening reaction of the aziridine exhibits excellent chemical and positional selectivity and high yield (> 90%). Mapping analysis was performed by reacting aziridine in aziPDMS with 5 (6) - carboxyfluoscein, a photoluminescent carboxylic acid derivative, to visualize the post - modification of aziPDMS.

At room temperature, aziPDMS of Example 1.6 and PDMS of Comparative Example 1 were incubated in a solution of 2.5 mM 5 (6) -carboxyfluoresin methanol: CH ₂ Cl ₂ = 1: 1 (by volume) for 18 hours, _{2 &lt;} RTI ID = 0.0 &_gt; Cl2 &lt; / RTI &gt; to remove unreacted 5 (6) -carboxyflucecein.

As shown in FIG. 2A, aziPDMS of Example 1.6 emits light easily visible to the naked eye when irradiated with ultraviolet rays (254 nm; 24 W of a mercury UV lamp), whereas PDMS of Comparative Example 1 emits light Did not release. The above results indicate that the ring-opening reaction of aziridine and carboxylic acid is efficient and orthogonal.

As shown in FIG. 7, the photoluminescence spectrum of aziPDMS exhibited? _Max at? 531 nm. The emission band was slightly reddish (Δλ _max = ~ 10) in solution (λ _max = ~ 521 nm in methanold) relative to free 5 (6) -carboxyfluorescine. The red shift of λ _max is an indicator to identify 5 (6) -carboxyfluorescein covalently attached to the skeleton of aziPDMS, and the interaction between 5 (6) -carboxyfluorescein molecules linked to PDMS is λ _max Because it induces change.

Test Example 4. Evaluation of Elongation

The modulus of elasticity of the aziPDMS of Example 1.6 before and after the ring opening reaction of aziridine and 5 (6) -carboxyfluorescein was measured to determine whether the elastic properties of aziPDMS of Example 1.6 changed during post-reforming. FIG. 2B is an intensity-elongation curve of the PDMS and aziPDMS fibers before and after the ring-opening reaction with the carboxylic acid compound (5 (6) -carboxyfluoscein). The tensile strengths for untreated and open aziPDMS were 0.66 MPa and 0.51 MPa, respectively (~ 1.3).

On the other hand, FIG. 2C shows an image of the ring-opened aziPDMS fiber of the present invention at different elongation ratios, and it was confirmed that the elongated aziPDMS fibers stretched to 200% sufficiently.

Test Example 5. Compatibility Study

In order to confirm that the aziPDMS according to the present invention can be compatible with the conventional PDMS, PDMS and aziPDMS were repeatedly thermally cured to produce a laminate structure as shown in FIG. 2d. To perform the mapping analysis on the entire structure, the prepared laminated film was cultured in a 5 (5) -carboxyfluoscein solution. As shown in FIG. 2d, the photoluminescence was selectively observed in the azi PDMS region other than the PDMS region, and the azi PDMS region was selectively post-modified. From the above results, it was confirmed that the ring opening reaction of aziridine in aziPDMS was effective for post-reforming the PDMS support.

Test Example 6. Characterization of aziPDMS according to aziridine content

AziPDMS films different in aziridine content in aziPDMS were prepared by adjusting the weight ratio x of aziridine having a terminal vinyl to the base while maintaining the weight ratio of the base and the curing agent in the same manner as in Example 1 and the properties according to the aziridine content .

Figure 3a shows a slight change in apparent optical clarity in aziPDMS films according to Examples 1.1 to 1.5. In addition, referring to the UV-vis absorption spectrum shown in Fig. 3B, the intensity of the absorption band at 259 nm linearly increased as the amount of aziridine increased.

To confirm the ring opening reaction with the aziridine content gradient, the aziPDMS films according to Examples 1.1 to 1.5 were incubated in a 2.5 mM 5 (6) -carboxyfluorescein solution for 18 hours at room temperature and then washed with chloroform and methanol , Dried in a hot oven and under vacuum. Figure 3c is an image of the films taken under visible light and UV irradiation. The photoluminescence intensities of ring - opened aziPDMS increased with increasing aziridine content. As shown in FIG. 3D, it was confirmed that the photoluminescence emission characteristics were linearly correlated with the content of aziridine.

Test Example 7. Evaluation of Substrate Range

Compounds having various functional groups such as carboxylic acid, thiol, alcohol and amine derivatives as a substrate for aziPDMS exchange may be used. Particularly, since fluorine atoms give a strong signal in XPS measurement, it is easy to confirm whether or not ring opening reaction of aziPDMS is due to XPS. Therefore, in the present invention, a fluorine-containing compound was used for the experiment.

AziPDMS of Examples 1.1 to 1.5 and PDMS of Comparative Example 1 were treated with a THF solution of 0.25 mM fluorine-containing compound at room temperature for 3 hours or 6 hours, then washed with pure THF, CH ₂ Cl ₂ and methanol, Dried in an oven and under vacuum. As shown in FIG. 3E, the F1s peak appeared in the XPS spectrum of ring-opened aziPDMS, but not in PDMS. The above results show a wide substrate range of the ring opening reaction of aziridine after the modification.

Test Example 8. Evaluation using surface wettability

As shown in Figure Ic, conventional PDMS generally exhibits low wettability (static contact angle of water droplet &amp;thetas; = ~ 113 DEG). The PDMS exhibits very low wettability by liquids of high dielectric constant such as water or methanol, whereas PDMS spreads to most regions on the surface by low dielectric constant liquids such as n-hexane or chloroform. The surface wettability of these PDMSs further exploited the post-modification of the aziPDMS post-site specificity (surface-to-volume).

As shown in Fig. 4, aziPDMS was made into a cubic body (1 cm x 1 cm x 1 cm), and then a polar solution (0.25 mM 5 (6) -carboxyfluorescein) CHCl ₃ : MeOH = 1: 5 by volume), washed with pure CHCl ₃ and MeOH, and dried under high temperature oven and vacuum. Solution is lower than the other light emitting compounds containing the dried cubes (0.25 mM 7- that emits blue light emission under 254 nm UV irradiation hydroxy coumarin) polarity (CHCl _3: 1 volume ratio: MeOH = 5) in sequence in the Lt; / RTI &gt; Washing the cubes in pure CHCl ₃ and MeOH, and dried under a high-temperature oven and vacuum, and sejeol.

When irradiated with ultraviolet light, the cube showed yellow and blue light emission on the surface and inside, respectively (Fig. 4A). This site-specific post-modification of aziPDMS was also confirmed in the photoluminescent image of the chopped film. The surface depth of the post-reform can be controlled by forming a gradient of the polarity of the solution. The photoluminescent compound 5 (6) -carboxyfluorescein was dissolved in various volume ratios of CHCl ₃ : MeOH co-solvent (0: 100 to 60:40), then the aziPDMS cube was cultured, washed, They were cultured in a non-polar solution to modified after (1 volume _{CHCl 3:: MeOH = 9)} . The surface depth was estimated using the above image analysis method. As the volume of methanol in the solution decreased after surface modification, the modified surface depth increased as shown in Figure 4b. This tendency can be confirmed by relating the% surface depth defined by the ratio of the volume ratio of methanol (directly related to the polarity of the solvent) to the half-width of the entire surface to the first post-modification surface depth (FIG. The% surface depth began to change at a point where the methanol ratio was 70%.

Claims (9)

A polymer represented by the following formula 1:
[Chemical Formula 1]

In the above formula (1)
Ph is a phenyl group,
a is an integer of 1 to 20,
b is an integer of 0 to 20,
c is an integer of 1 to 20,
l is an integer of 1 to 20,
m is an integer of 1 to 20; The method according to claim 1,
Wherein the aziridine group is opened by reacting with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group, and the compound is attached to the ring-opened aziridine moiety. The method according to claim 1,
Wherein the polymer exhibits elasticity. A compound represented by the following formula (2), a compound represented by the following formula (3) and a compound represented by the following formula (4) are reacted under a karstedt catalyst to obtain a compound represented by the following formula A process for producing a polydimethylsiloxane-based polymer having an aziridine group, comprising:
(2)

(3)

[Chemical Formula 4]

[Chemical Formula 1]

In the above Chemical Formulas 1 to 4,
Ph is a phenyl group,
a is an integer of 1 to 20,
b is an integer of 0 to 20,
c is an integer of 1 to 20,
l is an integer of 1 to 20,
m is an integer of 1 to 20,
n is an integer from 2 to 30,
a + b + c = n. 5. The method of claim 4,
Wherein the reaction is carried out at 50 to 100 DEG C for 0.5 to 3 hours. 5. The method of claim 4,
Wherein the compound of Formula 4 is prepared by reacting (1-benzylaziridin-2-yl) methanol with chlorodimethyl (vinyl) silane at 40 to 80 ° C. The method according to claim 6,
The above (1-benzylaziridin-2-yl)
Reacting ethyl 2,3-dibromopropanoate with benzylamine in the presence of a nitrogen stream and triethylamine to produce ethyl 1-benzylaziridine-2-carboxylate; And
Reacting the ethyl 1-benzyl aziridine-2-carboxylate with lithium aluminum hydride. 5. The method of claim 4,
0.5 to 2 parts by weight of the compound represented by the formula (3) and 0.02 to 0.2 part by weight of the compound represented by the formula (4) are added to 10 parts by weight of the compound represented by the formula (2) Gt; 5. The method of claim 4,
Reacting a compound represented by the formula (1) with a compound containing a carboxylic acid, an alcohol, an amine group or a thiol group to ring an aziridine group of the formula (1).

Images