KR100789730B1 - Acrylic ionic high molecule electric potential actuator material - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer potential driving material capable of manufacturing an ionic polymer-metal composite (IPMC) by replacing Nafion and the like.

At present, the polymer potential driving materials used for the manufacture of IPMC include Nafion, which is provided by a specific manufacturer, and these are expensive because there is no substitute material for the manufacture of IPMC. There is a problem that must be purchased only at the price.

Accordingly, an object of the present invention is to provide a polymer potential driving material for producing IPMC, which can be used by copolymerizing a hydrophobic acrylic monomer having a high hydrophobicity and a hydrophilic acrylic monomer having a carboxylic acid or sulfonic acid group, and the like.

Polymeric potential driving material, acrylic monomer, carboxylic acid, sulfonic acid group

Description

Acrylic ionic high molecule electric potential actuator material

The present invention relates to an ionic polymer potential driving material that can manufacture an ionic polymer-metal composite (IPMC) by replacing Nafion and the like.

Currently, electroactive polymer (EAP) whose shape is changed by external electrical stimulation is lighter than ceramic material or shape memory alloy, and it is easy to process, so it can be widely applied as an electroactive material. have.

In particular, ionic polymer-metal composite (IPMC) is a type of EAP, which has a structure with metal electrodes on both sides of a thin polymer membrane, and the metal electrode usually chemically reduces metal ions. By forming a voltage between the two electrodes, the electrode is bent toward the anode, which quickly responds to a relatively low external voltage of 10 V or less and has a large deformation amount.

Therefore, it is possible to design a light and flexible small actuator (actuator) using such an IPMC has been applied to a variety of applications, such as artificial muscles, micro robots, micro-pumps that mimic biological functions in the medical field.

However, at present, most of the potential commercially available polymer potential driving materials used in the manufacture of IPMC are fluorinated ionic polymer materials, such as Nafion of DuPont, Flemion of Asahi Glass, Aciplex of Asahi Chemical, etc. They have a chemical structure copolymerized with tetrafluoroethylene and fluorinated vinyl ethers having ionic groups of sulfonic acid or carboxylic acid at the ends of long branches, most of which are provided in the form of films having a thickness of 0.1 to 0.3 mm.

Therefore, at present, there is a problem that you need to purchase only at a high price because there is no material that can be used to substitute for the manufacture of IPMC.

Therefore, the present invention is to provide a new ionic polymer potential driving material that can manufacture IPMC in place of Nepion.

To this end, the present invention, when a voltage is applied between the positive electrode of the IPMC can not move the anion covalently fixed to the ionic polymer chain, but the ion-bonded metal cation moves with the hydrated water molecules toward the cathode (cathode) According to the driving principle that the cathode side swells and the anode side contracts, the film-shaped IPMC is bent toward the anode side. According to the driving principle, the polymer material capable of manufacturing IPMC is ion-transferred in a hydrophobic matrix. In view of the fact that the possible hydrophilic channels need to have a phase separation structure in which they are dispersed and connected to each other, an ionic polymer obtained by copolymerizing a hydrophobic acrylic monomer having a high hydrophobicity and a hydrophilic acrylic monomer having a carboxylic acid or a sulfonic acid group is prepared. .

The ionic polymer potential driving material of the present invention is prepared by copolymerizing a hydrophobic acrylic monomer having a high hydrophobicity and a hydrophilic acrylic monomer having a carboxylic acid or sulfonic acid group.

At this time, the hydrophobic acrylic monomers that can be used for the synthesis of the ionic copolymer of the present invention include fluorinated alkyl acrylate or fluorinated alkyl methacrylate, and specific examples are TA-N fluoroalkyl acrylate, TM manufactured and sold by DuPont. fluoroalkyl methacrylate.

In addition, examples of the hydrophilic monomer that can be used for synthesizing the ionic copolymer include acrylic acid, methacrylic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, and the like as the acrylic monomer having a carboxylic acid or a sulfonic acid group. .

In this case, the synthesis of the copolymer using the monomer may be polymerized using a radical, a cation, or an anionic polymerization initiator, and a solvent may be partially used together if necessary.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

<Example 1>

(1) Preparation of Acrylic Copolymer Membrane :

Fluoroalkyl acrylate (FA, Zonyl TA-N) and acrylic acid (AA) copolymer (PFAA) is a radical polymerization initiator that uses 0.3 phr of 2,2'-azobisisobutyronitrile (AIBN) at 60 ° C in a nitrogen atmosphere. Combined and synthesized.

The polymer was crushed and washed with methanol and acetone to wash residual monomers.

Detailed composition and physical properties of the synthesized acrylic copolymer are shown in Table 1.

These acrylic copolymers were dissolved in N, N-dimethylformamide (DMF, Aldrich) / 1,3-bis (trifluoromethyl) benzene mixed solvent with a volume ratio of 50/50, and then cast at a temperature of 80 ° C. on a Teflon plate for 24 hours. A 0.2 mm membrane was prepared.

These membranes were dried for 24 hours at 110 ℃ and vacuum conditions were used in the experiment.

(2) Manufacture of IPMC:

Fluorinated acrylic ionic polymer-platinum composites (IPMC) having platinum electrodes formed on both sides of the film were prepared by chemical reduction.

The compressed film was washed several times with deionized ultrapure water, immersed in ultrapure water at room temperature for 2 days, and swelled, followed by tetraammine platinum (II) chloride hydrate, Pt (NH ₃ ) _{4 at a} concentration of about 10 ^-2 M. Cl _{2 ·} x H ₂ O was dissolved in ultrapure water for 3 hours, and H ⁺ ions of the carboxylic acid group were exchanged with platinum complex ions.

The exchanged platinum complex ions were reduced at 40 ° C. with an aqueous solution of NaBH ₄ dissolved in 5 wt.% To prepare IPMC having platinum deposited on the film surface.

Platinum complex ion exchange and reduction operations were repeated four times, so that platinum of sufficient thickness precipitated on the surface. In the third and fourth reduction, the temperature was increased to 60 ° C.

 (3) Measurement:

When the potential of 3V, 5V, or 9V is added to the IPMC in one direction using the device shown in Figure 1, the current and bending strain are measured and shown in Figures 2 and 3.

The IPMC was cut into a ribbon with a width of 6 mm, and one end was fixed to the device to apply a voltage, and the other end was moved to the left and right by the voltage.

The length of the ribbon to drive was 25mm, the displacement was measured by a laser at a point 5mm from the end.

The sample was preliminarily run several times and the response values were measured to increase the reproducibility of the measurements.

Table 1. Acrylic Polymers of Example 1

  Sample Name  Monomer Supply Composition (Weight%)  Polymer composition  Equivalence of Polymer  Reduced viscosity (dL / g) weight %    Mole% FA AA FA AA FA AA PFAA20 80.0 20.0 93.0 7.0 62.8 37.2 1030 0.76 PFAA25 75.0 25.0 89.4 10.6 51.7 48.3 680 1.29 PFAA30 70.0 30.0 86.4 13.1 45.5 54.5 550 1.11 PFAA35 65.0 35.0 83.7 16.3 39.0 61.0 440 1.12

Figure 1. Schematic diagram of the drive measuring device

Figure 2.Current and displacement when (a) 3V, (b) 5V, and (c) 9V are applied to the PFAA25

Figure 3. Current and displacement when 5V is added to (a) PFAA25, (b) PFAA30, and (c) PFAA35

<Example 2>

Fluoroalkyl methacrylate (FMA, Zonyl TM) and acrylic acid (AA) copolymer (PFMAA) is a radical polymerization initiator that is synthesized by mass polymerization in a nitrogen atmosphere at 60 ° C using 0.3 phr of 2,2'-azobisisobutyronitrile (AIBN). It was.

The polymer was crushed and washed with methanol to wash residual monomers. Detailed composition and physical properties of the synthesized acrylic copolymer are shown in Table 2.

These acrylic copolymers were compression molded at 150 ° C. to prepare a membrane having a film thickness of about 0.17 mm.

IPMC was prepared in the same manner as in Example 1, but after preparing IPMC to observe the effect of the type of cation, the chloride salt of Li ⁺ , Na ⁺ , Ca ^{2 +} , (CH ₃ ) ₄ N ⁺ ion was prepared. It was immersed in an aqueous solution dissolved at a concentration of about 1N and replaced with the corresponding cation.

The measurement is shown in Figure 4 by measuring the degree of bending deformation when applied to IPMC alternately with ± 9V at 0.2Hz using the device shown in Figure 1.

Table 2. Acrylic Polymers of Example 2

Sample Name Monomer Supply Composition (Weight%) Polymer composition Equivalence of Polymer Reduced viscosity (dL / g) weight %    Mole% FMA AA FMA AA FMA   AA PFMAA20 80.0 20.0 91.1 8.9 58.2 41.8 816 0.98 PFMAA25 75.0 25.0 88.2 11.8 50.3 49.7 612 1.28 PFMAA30 70.0 30.0 86.3 13.7 45.9 54.1 524 1.39 PFMAA35 65.0 35.0 82.4 17.6 38.8 61.2 410 2.00

Figure 4. Substituted cation with (○) Li ⁺ , (△) Na ⁺ , (□) Ca ^{2 +} , (●) CH ₃ ) ₄ N ⁺ in IPMC made of PFMAA25, alternating 9V at 0.2Hz Displacement measured in one case

Example 3

The copolymer of FMA and 2-acrylamido-2-methyl-1-propanesulfonic acid (SA) (PFMAS) is a radical polymerization initiator that uses 0.3 phr of 2,2'-azobisisobutyronitrile (AIBN) at 60 ° C in a nitrogen atmosphere. Polymerized and synthesized.

In other words, FMA dissolved in 42.8% concentration in 1,3-bis (trifluoromethyl) benzene and AA, an initiator dissolved in 11.1% concentration in DMF were mixed and polymerized. The polymer was crushed and washed with MEK to wash residual monomers.

Detailed composition and physical properties of the synthesized acrylic copolymer are shown in Table 3.

These acrylic copolymers were compression molded at 160 ° C. to prepare a membrane having a film thickness of 0.1 mm.

IPMC was prepared in the same manner as in Example 1. After preparing the IPMC, the salt of Li ⁺ ions was dissolved in an aqueous solution of about 1N concentration and replaced with Li ⁺ cations. Figure 5 shows the change in displacement when 3V, 5V, or 9V is added.

Table 3. Acrylic Polymers of Example 3

Sample Name Monomer feed composition (weight%) Polymer composition Reduced viscosity (dL / g)   weight%   Mole% FMA SA FMA SA FMA SA PFMAS20 80.0 20.0 81.94 18.06 62.02 37.98 0.45 PFMAS25 75.0 25.0 74.18 25.82 72.06 27.94 0.64 PFMAS30 70.0 30.0 72.92 27.82 73.35 26.65 0.84 PFMAS35 65.0 35.0 70.74 29.26 51.60 48.40 0.62

Figure 5.Displacement observed when (a) 3V, (b) 5V and (c) 9V were added to IPMC:

              (________) PFMAS20, (_ _ _ _) PFMAS25,

              (_._._._) MAS30, (.......) PMAS25

According to the above embodiment, the preparation of IPMC using the ionic polymer potential driving material of the present invention in which the ionic polymer copolymerized with a hydrophobic acrylic monomer and a hydrophilic acrylic monomer having a carboxylic acid or sulfonic acid group in the form of a film It became possible.

As described above, it is possible to manufacture IPMC by replacing the ionic polymer potential driving material, which is composed of the structure of the present invention, which is currently used exclusively.

Claims (3)

An acrylic ionic polymer potential driving material prepared by copolymerizing a hydrophobic acrylic monomer composed of fluorinated alkyl acrylate or fluorinated alkyl methacrylate with a hydrophilic acrylic monomer having a carboxylic acid or sulfonic acid group. delete  The method of claim 1, wherein the hydrophilic acrylic monomer having a carboxylic acid or sulfonic acid group is an acrylic ionic polymer potential drive containing 5-30 wt.% Of acrylic acid, methacrylic acid, or 2-acrylamido-2-methyl-1-propanesulfonic acid. matter.