KR20220068893A - Polymer composition, shape memory polymer formed therefrom, and preparation method thereof - Google Patents

Abstract

The present invention relates to a polymer composition, a shape memory polymer formed therefrom, and a preparation method thereof, and more specifically, to a polymer composition which comprises: polycaprolactone polyol, isocyanate, poly(styrene-allylalcohol) and a catalyst, a shape memory polymer formed therefrom, and a preparation method thereof.

Description

Polymer composition, shape memory polymer formed therefrom, and method for manufacturing the same

The present invention relates to a polymer composition, a shape memory polymer formed therefrom, and a method for manufacturing the same.

Thermoplastic polymers are easily processed, but have the disadvantage of being easily corroded by chemical and physical stimuli. On the other hand, thermoset polymers have high chemical and physical stimuli stability because polymer chains are connected to each other, but have difficulty in reprocessing. Vitrimers are a new category of polymer materials with the easy processability of thermoplastic polymers and the chemical and physical stimuli stability of thermosetting polymers. These non-trimers are chemically linked by covalent bonds and have a structure capable of dynamic cross-linking, so they are reprocessing and self-healing materials.

A shape memory polymer (SMP) refers to a polymer with a shape memory effect in which a shape memorized under certain conditions is temporarily deformed and returned to its original state by external stimuli and changes in the environment. In shape-memory polymers, the shape-memory effect is due to the transformation of the polymer chain by external stimuli, so it responds to various stimuli such as light, pH, and electromagnetic fields in addition to heat.

As a related art, in Non-Patent Document 1 ( Macromolecules , 2017, 50, 6117-6127), commercial polybutylene terephthalate (Poly(butylene terephthalate), PBT) and a base catalyst are used to transesterify through transesterification. Epoxy non-trimer material that can be reprocessed has been prepared, and in Non-Patent Document 2 ( Polym . Chem ., 2019, 10, 136-144), the molar content of the base catalyst affects the transesterification reaction and mechanical properties. research has been conducted on In addition, in Non-Patent Document 3 (Nature Comm., 2018, 9, 1831), which is a technology utilized as a 3D printing material through related research, 3D printing based on a digital light processing (DLP) method using UV curing have performed

While the present applicant was conducting research on a non-trimeric material capable of transesterification, if the ester bond satisfies certain conditions in the presence of a hydroxyl monomer and a catalyst, it can be applied as a non-trimeric material capable of a dynamic bond exchange reaction. point was discovered, and using this, a polymer material with reshaping and shape memory properties was developed from a commercial polymer composition, and it was confirmed that a shape memory structure could be formed by using it as a 3D printing material, and the present invention was completed. .

Macromolecules, 2017, 50, 6117-6127 Polym. Chem., 2019, 10, 136-144 Nature Comm., 2018, 9, 1831

In one aspect, the purpose

An object of the present invention is to provide a polymer composition, a shape memory polymer formed therefrom, and a method for manufacturing the same.

In order to achieve the above object,

In one aspect,

A polymer composition comprising polycaprolactone polyol, isocyanate, poly(styrene-allyl alcohol) and a catalyst is provided.

In this case, the molar ratio ([NCO]/[OH]) of the NCO groups of the isocyanate to the OH groups of the polycaprolactone polyol is 0.9 to 2.5.

The polycaprolactone polyol and the isocyanate form a urethane crosslink,

The molar ratio of the OH groups of the poly(styrene-allyl alcohol) to the repeating unit (-COO-) of the polycaprolactone polyol and the total OH groups of the poly(styrene-allyl alcohol) [OH])*100) is 2 to 18.

In addition, the catalyst is an organometallic catalyst,

The molar ratio of the metal of the catalyst to the repeating unit (-COO-) of the polycaprolactone polyol and the total metal of the catalyst ([Zn]/([COO]+[Zn])*100) is 0.2 to 12.

In addition, the organometallic catalyst is zinc acetylacetonate hydrate (Zn(acac) ₂ ).

In another aspect,

A method for producing a polymer is provided, including a step of crosslinking polycaprolactone polyol, isocyanate and poly(styrene-allyl alcohol) under a catalyst.

The reaction may be carried out at a temperature of 120 °C to 140 °C.

In another aspect

Provided is a shape memory polymer composition comprising a polymer including a urethane crosslink formed by reacting polycaprolactone polyol and an isocyanate, poly(styrene-allyl alcohol), and a catalyst.

In another aspect

There is provided a shape memory polymer formed from the polymer composition or the shape memory polymer composition.

The shape memory polymer includes dynamic crosslinking.

In another aspect

A shape memory structure comprising the shape memory polymer is provided.

The polymer composition provided in the present invention can form a shape memory polymer having excellent mechanical properties and shape memory properties.

Since the shape memory polymer can be 3D printed, it can output a 4D printed object whose shape changes depending on the external environment, and can be used for smart materials such as soft robots.

1 is a schematic diagram showing a film manufacturing process using a polymer prepared according to an embodiment of the present invention.
FIG. 2 is a photograph showing a film manufactured by the film manufacturing process of FIG. 1 .
3 is a schematic diagram illustrating a process of forming a filament using a polymer prepared according to an embodiment and printing with a 3D pen.
4 is a photograph showing an embodiment of the filament manufacturing process of FIG. 3 and the manufactured filament.
5 is a photograph showing a non-laminated printing structure manufactured by printing a filament manufactured according to an embodiment with a 3D pen.
6 is a photograph showing a laminated printing structure manufactured by printing the filament prepared according to the embodiment with a 3D pen.
7 is a graph showing the results of FT-IR analysis of the polymer prepared according to the preparation example of the present invention.
8 is a photograph showing that the U _1.5 -PCL-PSA ₆ -Zn _c film prepared according to the example does not melt after 24 hours in a THF solvent and maintains the shape of the film.
9 is a graph of the gel fraction according to the PSA molar content of the polymer prepared according to the embodiment.
10 is a graph of the gel fraction according to the Zn(acac) ₂ molar content of the polymer prepared according to the embodiment.
11 is a graph of the DSC analysis result according to the PSA molar content of the polymer prepared according to the example.
12 is a graph of the DSC analysis result according to the Zn(acac) ₂ molar content of the polymer prepared according to the embodiment.
13 is a photograph confirming the reprocessing characteristics of the film prepared according to the embodiment.
14 is a graph showing the results of FT-IR analysis after reprocessing the film prepared according to the embodiment.
15 is a graph showing the result of analyzing the melting point (T _m ) change according to the number of reprocessing for the film manufactured according to the embodiment.
16 is a graph showing the results of analyzing the crystallinity (X _c %) change according to the number of reprocessing for the film manufactured according to the embodiment.
17 is a photograph confirming the self-healing properties according to the increase in temperature of the film of U _1.5 -PCL-PSA ₆ -Zn ₂ component prepared according to the embodiment through an optical microscope.
18 is a photograph confirming the self-healing properties according to an increase in temperature through an optical microscope for a film of U _1.5 -PCL-PSA ₆ -Zn ₄ prepared according to an embodiment.
19 is a photograph confirming the self-healing properties of the film of the U _1.5 -PCL-PSA ₆ -Zn ₄ component prepared according to the example through an optical microscope, and when exposed at 160° C. for 30 minutes, scratches on the surface are healed shows how to become
20 is a photograph confirming the shape memory characteristics of the film manufactured according to the embodiment.
21 is a photograph confirming the shape memory characteristics of the film manufactured according to the embodiment after reprocessing 3 times.
22 and 23 are photographs confirming the shape memory characteristics of the non-laminated printing structure manufactured according to the embodiment.
24 and 25 are photographs confirming the shape memory defect of the multilayer printing structure manufactured according to the embodiment.
26 is a photograph comparing and confirming the heat resistance of the laminated printing structure manufactured according to the Example and Comparative Example.

Hereinafter, the present invention will be described in detail.

On the other hand, the embodiment of the present invention can be modified in various other forms, the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

Furthermore, in the entire specification, "including" a certain element means that other elements may be further included, rather than excluding other elements, unless specifically stated otherwise.

In one aspect,

A polymer composition comprising polycaprolactone polyol, isocyanate, poly(styrene-allyl alcohol) and a catalyst is provided.

The polycaprolactone polyol and the isocyanate of the polymer composition form a urethane crosslink.

The polycaprolactone polyol may have a number average molecular weight (Mn) of 1200 to 5000, more preferably 1500 to 2500.

The poly(styrene-allyl alcohol) may have a number average molecular weight (Mn) of 500 to 5000, more preferably 1000 to 2000.

In this case, the molar ratio ([NCO]/[OH]) of the NCO groups of the isocyanate to the OH groups of the polycaprolactone polyol may be 0.9 to 2.5, 1.0 to 2.0, 1.1 to 1.7, and 1.3 to It can be 1.5.

By adjusting the content of [NCO]/[OH] of the polymer composition to the above range, it is possible to increase the gel fraction of the polymer produced by increasing the urethane crosslinking during the preparation of the polymer.

The molar ratio of the OH groups of the poly(styrene-allyl alcohol) to the repeating unit (-COO-) of the polycaprolactone polyol and the total OH groups of the poly(styrene-allyl alcohol) [OH])*100) may be 2 to 18, may be 4 to 14, and may be 6 to 10.

In addition, the catalyst is an organometallic catalyst, preferably zinc acetylacetonate hydrate (Zn(acac) ₂ ).

The molar ratio of the metal of the catalyst to the repeating unit (-COO-) of the polycaprolactone polyol and the total metal of the catalyst ([Zn]/([COO]+[Zn])*100) may be 0.2 to 12, and , may be 1 to 8, may be 2 to 6, may be 4.

By adjusting the poly(styrene-allyl alcohol) and catalyst contents of the polymer composition to the above ranges, non-trimer properties, that is, reworkability, self-healing properties, and shape memory properties can be further improved.

in another aspect

A method for producing a polymer is provided, including a step of crosslinking polycaprolactone polyol, isocyanate and poly(styrene-allyl alcohol) under a catalyst.

The reaction may be carried out at a temperature of 120 °C to 140 °C.

In the method for preparing the polymer, a polymer including a urethane cross-linkage formed by reacting a polycaprolactone polyol and an isocyanate may be formed, and the polymer including the urethane cross-linkage and the poly(styrene-allyl alcohol) are transesterified. Through this, it is possible to prepare a shape-memory polymer that forms dynamic cross-linking.

In the polymer manufacturing method, a shape memory polymer having excellent reworkability can be prepared by controlling the content of the poly(styrene-allyl alcohol) and the catalyst.

In another aspect,

Provided is a shape memory polymer composition comprising a polymer including a urethane crosslink formed by reacting polycaprolactone polyol and an isocyanate, poly(styrene-allyl alcohol), and a catalyst.

In another aspect

There is provided a shape memory polymer formed from the polymer composition or the shape memory polymer composition.

The shape memory polymer includes dynamic crosslinking.

By using the shape memory polymer, it is possible to form various types of shape memory structures, such as a one-dimensional (1D) filament form, a two-dimensional (2D) film form, and a three-dimensional (3D) three-dimensional figure form.

Since the shape memory polymer can be used as a 3D printing material, 3D printing, more specifically, 3D printing of a fused deposition modeling (FDM) method can be performed, and through this, a 4D deformable 4D according to external environmental factors (4D) can form a printing material.

In another aspect

A shape memory structure comprising the shape memory polymer is provided.

The shape memory structure may have various forms, such as, for example, a one-dimensional filament form, a two-dimensional film form, and a three-dimensional three-dimensional figure form.

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

However, the following examples and experimental examples are only to illustrate the present invention, the content of the present invention is not limited by the following examples.

Experiment preparation

Polycaprolactone diol (PCL, number average molecular weight (Mn): about 2000 g/mol, Sigma-Aldrich), poly(hexamethylene diisocyanate) ((Poly(hexamethylene diisocyanate), PHMDI, Sigma-Aldrich) , Zinc acetylacetonate hydrate, Zn(acac) ₂ , Sigma-Aldrich) poly(styrene-co-allyl alcohol) ((Poly(styrene-co-allyl alcohol), PSA, number average molecular weight (Mn): about 1200) g/mol, allyl alcolhol 40 mol%, Sigma-Aldrich) and tetrahydrofuran (Tetrahydrofuran, THF, stabilized, >99.9%, Samchun Pure Chemical Industries) were prepared and used All other reagents and solvents were supplied as standard Used as received from the company.

<Production example> Urethane crosslinked polycaprolactone (U _a -PCL) preparation

Polycaprolactone containing a urethane crosslink is named U _a -PCL, where a represents the molar ratio of NCO groups of PHMDI to OH groups of PCL ([NCO]/[OH]).

U _a -PCL was synthesized by the following method.

The molar feed ratio, [NCO]/[OH] of the NCO group of PHMDI compared to the OH group of PCL was changed under the conditions of Table 1 below.

First, PCL (2.50 g, 1.16 mmol), Zn(acac) ₂ (0.447 g, 0.118 mmol), and THF (5 mL) were placed in a 20 mL vial with a magnetic stirring bar and stirred for 1 hour. . PHMDI dissolved in THF (2 mL) was added to the vial at different ratios shown in Table 1 below, and the remaining THF was removed after stirring at room temperature for 1 hour. The vial was dried in a vacuum oven at 60° C. for 2 hours to obtain U _1.5 -PCL (refer to Scheme 1). At this time, the molar feed ratio of Zn of the catalyst to the ester (-COO-) repeating unit of U-PCL, [COO]:[Zn] was fixed at 98:2.

<Scheme 1>

a value ([NCO]/[OH]) PCL PHMDI Zn(acac) ₂ Preparation Example 1 0.9 2.50 g
(1.16 mmol) 0.471 g
(0.983 mmol) 0.118 g
(0.447 mmol) Preparation 2 1.0 2.50 g
(1.16 mmol) 0.526 g
(1.10 mmol) 0.118 g
(0.447 mmol) Preparation 3 1.1 2.50 g
(1.16 mmol) 0.581 g
(1.21 mmol) 0.118 g
(0.447 mmol) Preparation 4 1.3 2.50 g
(1.16 mmol) 0.686 g
(1.43 mmol) 0.118 g
(0.447 mmol) Preparation 5 1.5 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.118 g
(0.447 mmol) Preparation 6 1.7 2.50 g
(1.16 mmol) 0.897 g
(1.87 mmol) 0.118 g
(0.447 mmol) Preparation 7 2.0 2.50 g
(1.16 mmol) 1.05 g
(2.20 mmol) 0.118 g
(0.447 mmol) Preparation 8 2.5 2.50 g
(1.16 mmol) 1.32 g
(2.75 mmol) 0.118 g
(0.447 mmol)

<Example 1-6> Urethane crosslinked polycaprolactone vitrimer (U _1.5 -PCL-PSA _b -Zn ₂ ) manufacturing (1)

Polycaprolactone nontrimer containing urethane crosslink is named U _a -PCL-PSA _b -Zn _c , where a is the molar ratio of NCO groups of PHMDI to OH groups of PCL ([NCO]/[OH]) represents, b represents the repeating unit of polycaprolactone polyol (-COO-) and the molar ratio of OH groups of PSA to the total OH groups of PSA ([OH]/([COO]+[OH])*100), c represents the repeating unit (-COO-) of polycaprolactone polyol and [Zn]/([COO]+[Zn]*100), which is the molar supply ratio of Zn to the total Zn of the catalyst.

U _1.5 -PCL-PSA _b -Zn ₂ was synthesized by the following method (refer to Scheme 2).

PCL (2.50 g, 1.16 mmol), Zn(acac) ₂ (0.447 g, 0.118 mmol), and THF (5 mL) were placed in a 20 mL vial with a magnetic stirring bar and stirred for 1 hour. PHMDI (0.791 g, 1.65 mmol) dissolved in THF (2 mL) was added to the vial, stirred at room temperature for 1 hour, and PSA dissolved in THF (5 mL) was added to the content shown in Table 2 below. After that, the remaining THF was removed. The vial was dried in a vacuum oven at 60° C. for 2 hours, and then heat-treated in a vacuum oven at 120° C. for 20 hours to obtain U _1.5 -PCL-PSA ₆ . At this time, [Zn]/([COO]+[Zn]*100), which is the molar supply ratio of Zn to the total Zn of the repeating unit (-COO-) of the polycaprolactone polyol and the catalyst, was fixed at 2, [NCO] The molar feed ratio of /[OH] was fixed at 1.5.

<Scheme 2>

b value
([OH]/([COO]+[OH])*100) PCL PHMDI PSA Zn(acac) ₂ Example 1 2 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.0833 g
(0.0694 mmol) 0.118 g
(0.447 mmol) Example 2 4 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.167 g
(0.139 mmol) 0.118 g
(0.447 mmol) Example 3 6 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.118 g
(0.447 mmol) Example 4 10 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.417 g
(0.347 mmol) 0.118 g
(0.447 mmol) Example 5 14 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.595 g
(0.496 mmol) 0.118 g
(0.447 mmol) Example 6 18 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.757 g
(0.631 mmol) 0.118 g
(0.447 mmol)

<Example 7-13> Urethane cross-linked polycaprolactone vitrimer (U _1.5 -PCL-PSA _6- -Zn _c ) manufacturing

U _1.5 -PCL-PSA _{6 -} -Zn _c was synthesized by the following method.

PCL (2.50 g, 1.16 mmol), Zn(acac) ₂ , and THF (5 mL) were placed in a 20 mL vial with a magnetic stirring bar and stirred for 1 hour. At this time, Zn(acac) ₂ was added with different contents shown in Table 3 below. PHMDI (0.791 g, 1.65 mmol) dissolved in THF (2 mL) was added to the vial, and after stirring at room temperature for 1 hour, PSA (0.260 g, 0.217 mmol) dissolved in THF (5 mL) was added. THF was removed.

The vial was dried in a vacuum oven at 60° C. for 2 hours, and then heat-treated in a vacuum oven at 120° C. for 24 hours to obtain U _1.5 -PCL-PSA ₆ -Zn ₂ .

At this time, the molar supply ratio of [NCO]/[OH] was fixed to 1.5, and the molar supply ratio of [OH]/([COO]+[OH])*100 was fixed to 6.

c value
([Zn]/([COO]+[Zn]*100) PCL PHMDI PSA Zn(acac) ₂ Example 7 12 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.749 g
(2.84 mmol) Example 8 8 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.477 g
(1.81 mmol) Example 9 6 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.350 g
(1.33 mmol) Example 10 4 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.229 g
(0.868 mmol Example 11 2 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.112 g
(0.425 mmol Example 12 One 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.0555 g
(0.210 mmol) Example 13 0.2 2.50 g
(1.16 mmol) 0.791 g
(1.65 mmol) 0.260 g
(0.217 mmol) 0.0110 g
(0.0417 mmol)

<Example 14> Preparation of shape memory polymer film

The polymers prepared in Preparation Examples 1 to 8 and Examples 1 to 13 were put in a SUS 30 mm (L) × 30 mm (W) × 0.2 mm (T) mold, and hot pressed at 170° C. for 30 minutes at 10 MPa. was performed to prepare a film shape (see FIGS. 1 and 2). The prepared film was further dried at 70° C. under vacuum conditions for 12 hours before analyzing the experimental examples to be described later.

<Example 15> Manufacturing of shape memory polymer filaments

About 20 g of the polymer U _1.5 -PCL-PSA ₆ -Zn ₄ prepared in Example 10 was put into a filament extruder and extruded at 180° C. at a speed of 2 to 3 to prepare a filament (see FIGS. 3 and 4).

<Example 16> Manufacturing of shape memory polymer 3D structure

A 3D structure was prepared by printing the filament prepared in Example 15 using a 3D pen in a welding molding process (FDM) method.

<Comparative Example 1> Commercial PCL 3D structure manufacturing

A 3D structure was prepared by printing a commercially available polycaprolactone (PCL) filament using a 3D pen in a deposition molding process (FDM) method.

<Comparative Example 2> Preparation of shape memory polymer film without PSA crosslinking agent

U _1.5 -PCL-PSA ₀ -Zn ₂ polymer without PSA crosslinking agent was placed in a SUS 30 mm (L) × 30 mm (W) × 0.2 mm (T) mold, and heated to 10 MPa at 170°C for 30 minutes A press was performed to prepare a film shape.

<Experimental Example 1> Fourier transform infrared (FT-IR) analysis

In order to confirm the polymerization and structure of the urethane crosslinked polycaprolactone (U _a -PCL) prepared in Preparation Examples 1 to 8, attenuated total reflection (ATR) equipment was used in the Bruker Alpha-P FT-IR spectrometer. The analysis was performed using , and the analysis results are shown in FIG. 7 .

As shown in FIG. 7 , as a result of urethane crosslinking, it was confirmed that the isocyanate of PHMDI appeared at 2270 cm ⁻¹ disappeared and urethane crosslinking proceeded through the urethane peak appearing at 1700 cm ⁻¹ .

<Experimental Example 2> Gel fraction (f) _g )measurement

The following experiment was performed to confirm the gel fraction of the film prepared in Example 14.

About 20 mg of the film prepared in Example 14 was put into a 10 mL vial, and THF enough to submerge the film was added. After the vial was stored at room temperature for 24 hours, the remaining film was dried under vacuum conditions at 60° C. for 12 hours. The gel fraction (f _g ) was calculated through Equation 1 below, and the analysis results are shown in FIGS. 8 to 10 and Tables 4 to 6 below.

<Equation 1>

8 is a photograph observing the state of the film prepared according to the embodiment after immersion in THF solvent for 24 hours. As shown in FIG. 8, the film prepared according to the embodiment does not dissolve in THF and maintains the shape of the film can be checked

In addition, as shown in Table 4, FIGS. 9 and 10, the a value ([NCO]/[OH]) and the b value ([OH]/([COO]+[OH])*100) increased as the It can be seen that the value of the gel fraction (f _g (%)) increases, and it can be seen that the gel fraction decreases as the value of c ([Zn]/([COO]+[Zn]*100)) increases. .

Through this, it can be seen that the gel fraction can be controlled by controlling the contents of PHMDI, PSA and catalyst.

<Experimental Example 3> Thermogravimetric analysis (TGA) analysis

Thermogravimetric analysis (TGA) was performed on the polymers of Preparation Examples 1 to 8 and Examples 1 to 13 to measure the thermal stability of the film prepared in Example 14. At this time, TGA was performed using a TA Instrument TGA Q5000 under a nitrogen atmosphere, and the results regarding the temperature (T _TFA-95% (° C.)) at which the weight loss of 5% was shown are shown in Tables 4 to 6 below.

Through this, it can be confirmed that the polymers of Preparation Examples 1 to 8 and Examples 1 to 13 show thermal stability at 200° C. or less.

<Experimental Example 4> Differential scanning calorimeter (DSC) analysis

Evaluation of changes in the melting point (T _m ), crystallization temperature (T _c ), crystallinity (X _c (%)) of the film prepared in Example 14 for the polymers of Preparation Examples 1 to 8 and Examples 1 to 13 To do this, differential scanning calorimetry (DSC) analysis was performed.

At this time, DSC was performed using TA instruments DSC Q1000 under a nitrogen atmosphere, and the results are shown in FIGS. 11 and 12 and Tables 4 to 6 below. In addition, the degree of crystallinity (X _c (%)) was calculated through Equation 2 below based on the melting point (T _m ) result obtained through the above experiment.

<Equation 2>

As shown in Tables 4, 5, and 6 below, as the a-value ([NCO]/[OH]) and b-value ([OH]/([COO]+[OH])*100) increased, the crosslinking density decreased. It can be seen that the melting point (T _m ) and the degree of crystallinity (X _c (%)) decreased with increasing, and it was also confirmed that the melting point (T _m ) disappeared as the content of PSA increased.

From the above results, the molar ratio of the repeating unit (-COO-) of the polycaprolactone polyol, which is the b value, and the OH groups of the PSA to the total OH groups of the PSA ([OH]/([COO]+[OH])* It can be seen that 100) is 10 or less, and more preferably 2 to 10 are more appropriate.

a value T _m (℃) T _c (℃) X _c (%) T _{TFA -95%} (℃) f _g (%) Preparation Example 1 0.9 48 17 39.48 241 37 Preparation Example 2 1.0 46 11 37.74 219 36 Manufacturing Example 3 1.1 46 10 36.13 232 37 Manufacturing Example 4 1.3 46 2 23.75 220 65 Manufacturing Example 5 1.5 41 -20 22.79 231 68

b value T _m (℃) T _c (℃) X _c (%) T _{TFA -95%} (℃) f _g (%) Example 1 2 48 8 24.3 234 49.39 Example 2 4 41 -9 20.1 234 73.91 Example 3 6 40 -8 15.5 240 74.21 Example 4 10 31 - 5.26 236 82.69 Example 5 14 - - - 231 69.68 Example 6 18 - - - 236 89.64

c value T _m (℃) T _c (℃) X _c (%) T _{TFA -95%} (℃) f _g (%) Example 7 12 35 - 2.2 216 36 Example 8 8 36 - 2.5 221 45 Example 9 6 36 - 13 223 62 Example 10 4 38 -19 18 223 75 Example 11 2 38 -10 20 254 78 Example 12 One 38 -12 25 281 80 Example 13 0.2 33 -25 25 315 95

<Experimental Example 5> Confirmation of reprocessing characteristics

The following experiment was performed to confirm the reprocessing properties of the film through the dynamic bonding ability using the transesterification reaction of the polymer prepared according to the example.

For the polymers of Examples 7 to 13 (U _1.5 -PCL-PSA _{6 -} -Zn _c ) prepared by varying the catalyst content, the film prepared by the method of Example 14 and U _1.5 -PCL without PSA crosslinking agent -PSA ₀ -Zn ₂ For the polymer, the film prepared by the method of Example 14 (Comparative Example 2) was cut into small pieces, and then again as in Example 14, SUS 30 mm (L) × 30 mm (W ) × 0.2 mm (T) into a mold, and hot press at 170 ° C. for 30 minutes at 10 MPa to form a film, and the melting point (T _m ) and crystallinity (X _c %) were analyzed.

13 is a photograph showing the reusability of the polymer of Example 11, and FIGS. 14 to 15 are FT-IR analysis results according to the number of reprocessing after manufacturing a film from the polymer of Example 11, melting point (T _m ) change and a graph comparing the crystallinity (X _c %) change.

As a result of the analysis, the film of Comparative Example 2 prepared with the polymer U _1.5 -PCL-PSA ₀ -Zn ₂ without the PSA cross-linking agent exhibited deterioration in properties that were easily broken after reprocessing. On the other hand, as shown in FIG. 13 , in the case of the film prepared from the polymer of Example 11 (U _1.5 -PCL-PSA ₆ -Zn ₂ ) containing the PSA crosslinking agent, almost no change in physical properties was observed with the naked eye after reprocessing. In addition, as shown in FIG. 14 , it can be seen that there is no significant change in the molecular structure even after reprocessing, and as shown in FIGS. 15 and 16 , there is also a large change in the melting point (T _m ) and crystallinity (X _c %). It can be seen that it does not appear.

From the above results, it can be seen that the hydroxy functional group of the PSA crosslinking agent affects the transesterification reaction, thereby increasing reworkability.

<Experimental Example 6> Confirmation of self-healing properties

The following experiment was performed to confirm the self-healing properties of the film through the dynamic binding ability using the transesterification reaction of the polymer prepared according to the example.

10 mm × 10 mm prepared by the method of Example 14 for the polymer of Example 11 (U _1.5 -PCL-PSA ₆ -Zn ₂ ) and the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) After making scratches on the film, the temperature was raised from 30° C. to 160° C. at a rate of 10° C./min, and the presence or absence of changes in the scratches generated on the film was observed, and the results are shown in FIGS. 17 to 18 . In addition, after making a scratch on the same film, heat was applied at 160° C. for 30 minutes to observe whether or not there was a change in the scratch generated on the film, and the results are shown in FIG. 19 .

As shown in FIGS. 17 and 18 , it was confirmed that the scratches gradually disappeared after the temperature was raised, and Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₂ ) compared to Example 11 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) ), it was confirmed that the scratches disappeared at a faster rate in the film made of the polymer.

In addition, as shown in FIG. 19 , it was confirmed that the scratches disappeared when heat was applied to the scratched film at 160° C. for 30 minutes.

Through this, it can be seen that the polymer according to the embodiment has self-healing properties.

<Experimental Example 7> Confirmation of shape memory characteristics (film)

The following experiment was performed to confirm the shape memory properties of the films prepared using the polymers of Examples.

Referring to Figure 20, the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) was prepared as a film having a permanent shape of 5 mm × 30 mm by the method of Example 14 in a straight line.

The prepared film was changed into a folded form in an oven at 60 ° C., and then fixed in a freezer at a temperature below the crystallization temperature (T _c ) for 10 minutes to obtain a film having a temporary shape. When the film fixed in a temporary shape was exposed to a temperature (60° C.) higher than the melting point (T _m ), it was confirmed that the film returned to the permanent straight shape.

In addition, referring to FIG. 21 , the film was reprocessed twice in the same manner as in Experimental Example 5 to prepare a film having a permanent shape of 5 mm × 30 mm in a straight line. After that, in order to change the permanent shape of the reprocessed film, it was changed to a semi-folded shape in an oven at 140 ° _C. . Thereafter, the semi-folded film was changed to a straight shape in an oven at 60 ° C., and then fixed for 10 minutes in a freezer at a temperature below the crystallization temperature (T _c ) to obtain a film having a temporary shape. When the film fixed in a temporary shape was exposed to a temperature (60° C.) higher than the melting point (T _m ), it was confirmed that the film returned to the permanent shape of the semi-folded shape.

From the above results, it can be seen that the film prepared using the polymer of the example has shape memory properties.

<Experimental example 8> Confirmation of shape memory characteristics (print structure- non-stacked )

The following experiment was performed to confirm the shape memory characteristics of the non-stacked printed structure manufactured using the polymer of the example.

Referring to FIG. 22, the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) was prepared in a bent shape by the method of Example 15, and then changed to a straight shape in an oven at 60 ° C. Then, the crystallization temperature (T _c ) was fixed for 10 minutes in a freezer at a temperature below the temperature to obtain a structure having a temporary shape of a straight line. When the temporary structure was exposed to a temperature (60°C) higher than the melting point (T _m ), it was confirmed that the structure returned to its initial bent shape.

In addition, referring to FIG. 23 , after preparing a star-shaped print structure using the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) by the method of Example 15, it was heated in an oven at 60° C. to form a pentagonal shape. and then fixed in a freezer at a temperature below the crystallization temperature (T _c ) for 10 minutes to obtain a structure having a temporary shape of a pentagon. When the temporary-shaped structure was exposed to a temperature (60° C.) higher than the melting point (T _m ), it was confirmed that it returned to the initial state of the star shape.

From the above results, it can be seen that the non-laminated print structure manufactured using the polymer of the embodiment has shape memory characteristics.

<Experimental example 9> Confirmation of shape memory characteristics (print structure- stacked )

The following experiment was performed to confirm the shape memory characteristics of the stacked-type printed structure manufactured using the polymer of Example.

24, the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) was prepared in a tetrahedral shape by the method of Example 16, and then changed to a crumpled form in an oven at 60 ° C. Then, the crystallization temperature (T _c ) was fixed for 10 minutes in a freezer at a temperature below the temperature to obtain a tetrahedral structure with a temporary crumpled shape. When the temporary structure was exposed to a temperature (60° C.) higher than the melting point (T _m ), it was confirmed that it returned to the tetrahedral shape of the initial state.

In addition, referring to FIG. 25 , the polymer (U _1.5 -PCL-PSA ₆ -Zn ₄ ) of Example 10 was used to prepare a drawbridge structure in which the legs were lowered by the method of Example 16, and then both legs were heated in an oven at 60°C. After changing to an elevated state, it was fixed in a freezer at a temperature below the crystallization temperature (T _c ) for 10 minutes to obtain a drawbridge structure with a temporarily raised leg. When the temporary shape structure was exposed to a temperature (60° C.) higher than the melting point (T _m ), it was confirmed that the initial state of the bridge was returned to the lowered drawbridge structure.

From the above results, it can be seen that the multilayer print structure manufactured using the polymer of the embodiment has shape memory characteristics.

<Experimental Example 10> U _1.5 - PCL - PSA ₆ - Zn ₄ of Heat resistance check

The following experiment was performed to confirm the heat resistance of the laminated print structure manufactured using the polymer of the example, and the results are shown in FIG. 26 .

Referring to FIG. 26 , the drawbridge structure prepared using the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) and the drawbridge structure prepared in Comparative Example 1 were evaluated for the melting point (T _m ) of commercial PCL. When exposed to an oven at a temperature of 80° C. for 5 minutes, the structure prepared with commercial PCL melted, but the structure prepared with the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) did not melt and did not melt. I was able to see how to keep it. Unlike commercial PCL, it was confirmed that the polymer of Example 10 (U _1.5 -PCL-PSA ₆ -Zn ₄ ) had heat resistance that did not melt even though it had a melting point because it was cross-linked.

Claims (12)

A polymer composition comprising polycaprolactone polyol, isocyanate, poly(styrene-allyl alcohol) and a catalyst.
According to claim 1,
The molar ratio of the NCO groups of the isocyanate to the OH groups of the polycaprolactone polyol ([NCO]/[OH]) is 0.9 to 2.5, the polymer composition.
According to claim 1,
The polycaprolactone polyol and the isocyanate form a urethane crosslink, a polymer composition.
According to claim 1,
The molar ratio of the OH groups of the poly(styrene-allyl alcohol) to the repeating unit (-COO-) of the polycaprolactone polyol and the total OH groups of the poly(styrene-allyl alcohol) [OH]) * 100) is 2 to 18, the polymer composition.
According to claim 1,
The catalyst is an organometallic catalyst,
The molar ratio of the metal of the catalyst to the repeating unit (-COO-) of the polycaprolactone polyol and the total metal of the catalyst ([Zn]/([COO]+[Zn])*100) is 0.2 to 12, a polymer composition.
6. The method of claim 5,
The organometallic catalyst is zinc acetylacetonate hydrate (Zn(acac) ₂ ), a polymer composition.
A method for producing a polymer, comprising: crosslinking polycaprolactone polyol, isocyanate and poly(styrene-allyl alcohol) under a catalyst.
8. The method of claim 7,
The reaction is made at a temperature of 120 ℃ to 140 ℃, a method of producing a polymer.
A shape memory polymer composition comprising a polymer comprising a urethane crosslink formed by reacting polycaprolactone polyol and isocyanate, poly(styrene-allyl alcohol), and a catalyst.
A shape memory polymer formed from the polymer composition of claim 1 or the shape memory polymer composition of claim 9 .
11. The method of claim 10,
The shape memory polymer comprises a dynamic crosslinking, shape memory polymer.
A shape memory structure comprising the shape memory polymer of claim 9 .

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