Patent ID: 12215193

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical idea of the present invention is not limited to the embodiments described herein and may be embodied in other forms. The embodiments introduced herein are provided to sufficiently deliver the spirit of the present invention to those skilled in the art so that the disclosed contents may become thorough and complete.

When it is mentioned in the specification that one element is on another element, it means that the first element may be directly formed on the second element or a third element may be interposed between the first element and the second element. Further, in the drawings, the thicknesses of the membrane and areas are exaggerated for efficient description of the technical contents.

Further, in the various embodiments of the present specification, the terms such as first, second, and third are used to describe various elements, but the elements are not limited to the terms. The terms are used only to distinguish one element from another element. Accordingly, an element mentioned as a first element in one embodiment may be mentioned as a second element in another embodiment. The embodiments illustrated here include their complementary embodiments. Further, the term “and/or” in the specification is used to include at least one of the elements enumerated in the specification.

In the specification, the terms of a singular form may include plural forms unless otherwise specified. Further, the terms “including” and “having” are used to designate that the features, the numbers, the steps, the elements, or combinations thereof described in the specification are present, and are not to be understood as excluding the possibility that one or more other features, numbers, steps, elements, or combinations thereof may be present or added.

Further, in the following description of the present invention, a detailed description of known functions or configurations incorporated herein will be omitted when it may make the subject matter of the present invention unnecessarily unclear.

Although the invention has been described in detail with reference to exemplary embodiments, the scope of the present invention is not limited to a specific embodiment and should be interpreted by the attached claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Amino acid containing a biomass-derived pyrrolidone group and a method for preparing the same according to an embodiment of the present invention will be described.

For the preparation of the amino acid containing the biomass-derived pyrrolidone group, itaconic acid and diamine may be provided. The itaconic acid may be represented by [Formula 1] below. According to one embodiment, the itaconic acid may be a natural product-derived monomer.

The diamine may be represented by [Formula 2] below, and may be a diamine-based monomer having 2 to 13 carbon atoms.

For example, the diamine-based monomer may be any one of 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, and 1,13-diaminotridecane, which have 2 to 13 carbon atoms.

Amino acid containing a biomass-derived pyrrolidone group according to an embodiment of the present invention, which is represented by [Formula 3] below, may be prepared by Michael addition reaction and amidation of the itaconic acid and the diamine. For example, 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA), which is the amino acid containing the biomass-derived pyrrolidone group, may be prepared by Michael addition reaction and amidation of the itaconic acid and 1,10-diaminodecane, which is one of the diamine.

Specifically, the method for preparing the amino acid containing the biomass-derived pyrrolidone group may include preparing a salt-type monomer, and heating the salt-type monomer to prepare the amino acid containing the biomass-derived pyrrolidone group.

In the preparing of the salt-type monomer, this preparation may be performed with an itaconic acid solution and a diamine solution by dissolving the itaconic acid and the diamine in a solvent, respectively. For example, the solvent may be any one of alcohols such as ethyl alcohol, methyl alcohol, etc.

In the preparing of the salt-type monomer, a heating process may be performed in such a way that the prepared itaconic acid solution and the diamine solution are added and mixed in a reaction vessel and heat is applied thereto. The salt-type monomer including the itaconic acid and the diamine, represented by [Formula 4] below, may be prepared by the above process.

A heating process in which heat is applied to the salt-type monomer may be performed, and thus Michael addition reaction may be performed. Accordingly, an intermediate product represented by [Formula 5] below may be prepared. With respect to a form of a heater used in the heating process, a type thereof is not particularly limited. For example, the heater may be any one of a heater, a hot plate, or a heating coil.

The intermediate product represented by above [Formula 5] may be heated to prepare the amino acid containing the biomass-derived pyrrolidone group represented by above [Formula 3]. For example, the intermediate product may be heated at 240° C.

A bionylon having triple shape memory effects using the amino acid containing the biomass-derived pyrrolidone group and a method for preparing the same according to the embodiment of the present invention described above will be described.

An amino acid containing a biomass-derived pyrrolidone group according to an embodiment of the present invention and α,ω-aliphatic amino acid may be provided. For example, 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA) and α,ω-aliphatic amino acid may be provided.

The α,ω-aliphatic amino acid may be represented by [Formula 6] below, and may be an α,ω-aliphatic amino acid having 4, 9, 10, 11, or 12 carbon atoms.

According to one embodiment, the α,ω-aliphatic amino acid may be commercially available.

For example, the α,ω-aliphatic amino acid may be any one of 1,4-aminobutanoic acid, 1,9-aminononanoic acid, 1,10-aminodecanoic acid, 1,11-aminoundecanoic acid, and 1,12-aminododecanoic acid.

A nylon copolymer may be prepared by condensation polymerization reaction of the amino acid containing the biomass-derived pyrrolidone group and the α,ω-aliphatic amino acid. A nylon copolymer represented by [Formula 7] below may be prepared by condensation polymerization reaction of the amino acid containing the biomass-derived pyrrolidone group represented by above [Formula 3] and the α,ω-aliphatic amino acid represent by above [Formula 6]. x represented by [Formula 7] below may be the number of the amino acids containing the biomass-derived pyrrolidone group involved in the condensation polymerization reaction, and y may be the number of the α,ω-aliphatic amino acids involved in the condensation polymerization reaction. In addition, n, m, x, and y represented by [Formula 7] below may be positive integers.

The condensation polymerization reaction may be an amidation between an amine group (—NH2) and carboxyl acid (—COOH) of the amino acid containing the biomass-derived pyrrolidone group, and carboxylic acid (—COOH) and an amine group (—NH2) of the α,ω-aliphatic amino acid, from which a water molecule (H2O) is generated and discharged, thereby preparing the nylon copolymer having an amide bond.

The method for preparing the nylon copolymer may include a heating process and a stirring process of a reactant.

A heating process may be performed in such a way that the amino acid containing the biomass-derived pyrrolidone group and the α,ω-aliphatic amino acid may be added into a reaction vessel as the reactant, and heat is applied to the reaction vessel under a nitrogen (N2) atmosphere. With respect to a form of a heater used in the heating process, a type thereof is not particularly limited. For example, the heater may be any one of a heater, a hot plate, or a heating coil. In addition, the heating process for the reaction vessel may be performed at 240° C. for two hours. Furthermore, the reaction in the reaction vessel may further include a stirring process. For example, a stirring speed in the stirring process may be 160 rpm. With the heating process and the stirring process, the condensation polymerization reaction of the amino acid containing the biomass-derived pyrrolidone group and the α,ω-aliphatic amino acid may be performed to prepare the nylon copolymer.

The nylon copolymer may have two phase transition temperatures (a glass transition temperature (Tg) and a melting temperature (Tm)). Based on the two phase transition temperatures (the glass transition temperature (Tg) and the melting temperature (Tm)), the nylon copolymer may have a glass state section at the glass transition temperature (Tg) or lower, a rubbery state section between the glass transition temperature (Tg) and the melting temperature (Tm), and a melt state section at the melting temperature (Tm) or higher, in which a storage modulus is drastically changed and the storage modulus is constantly maintained in the melt state section at the melting temperature or higher. The nylon copolymer may be prepared by condensation polymerization reaction between the amino acid containing the biomass-derived pyrrolidone group in a molar content of 20% to 60% and the α,ω-aliphatic amino acid in a molar content of 80% to 40%. Accordingly, the nylon copolymer (nylon copolymer) may have a shape fixed, deformed and recovered through two steps based on the two phase transition temperatures (glass transition temperature (Tg) and melting temperature (Tm)), thereby providing triple shape memory effects.

If a molar content of the amino acid containing the biomass-derived pyrrolidone group is less than 20%, there may be no storage modulus in the melt state section at the melting temperature (Tm) or higher, and if a molar content of amino acid containing the biomass-derived pyrrolidone group is more than 60%, there may be no melting point (Tm), thereby failing to provide two phase transition temperatures (glass transition temperature (Tg) and melting point (Tm)), such that two steps of shape deformation and fixing may not be easy. Accordingly, if a molar content of the amino acid containing the biomass-derived pyrrolidone group is less than 20% and if a molar content of the amino acid containing the biomass-derived pyrrolidone group is more than 60%, it may not be easy to prepare a bionylon with triple shape memory effects.

The nylon copolymer prepared according to the embodiment of the present invention described above may have a melting temperature (Tm) of 101.4 to 167.6° C., a glass transition temperature (Tg) of 37.4 to 44.4° C., and an intrinsic viscosity of 1.16 to 1.18 ml/g.

Hereinafter, a method for using a nylon copolymer having triple shape memory effects according to the embodiment of the present invention described above will be described.

An initial shape (A) of the nylon copolymer may be primarily deformed by a force applied from outside at a melting temperature (Tm) or higher. The primarily deformed nylon copolymer may maintain a shape (B) of the primarily deformed nylon copolymer as it is even after cooling down to the glass transition temperature (Tg) and removing the force having caused the primary deformation. The primarily deformed nylon copolymer may be secondarily deformed by the force applied from outside around the glass transition temperature (Tg). The secondarily deformed nylon copolymer may maintain a shape (B) of the secondarily deformed nylon copolymer even after cooling down to room temperature and removing the force having caused the secondary deformation. In addition, when the secondarily deformed nylon copolymer is heated again to the glass transition temperature (Tg), and the shape (B) of the primarily deformed nylon copolymer may be recovered. In addition, when the primarily deformed nylon copolymer is heated again to the melting temperature (Tm), and the initial shape (A) of the nylon copolymer may be restored to a state just before the primary deformation occurs. Accordingly, the nylon copolymer prepared according to an embodiment of the present invention may have triple shape memory effects as the nylon copolymer is capable of shape deformation, fixing and recovery through the two steps. A shape recovery temperature may be easily controlled by adjusting a molar content of the amino acid containing the biomass-derived pyrrolidone group, which is used when preparing the nylon copolymer.

Unlike the embodiment of the present invention described above, an existing shape memory polymer has dual shape memory effects, in which an initial permanent shape is memorized, temporarily deformed by an appropriate stimulus, and then restored to an original initial shape. The dual shape memory polymer is not easy to control a shape recovery temperature to a desired level, and thus there is a limit to the application in a wide range of fields.

However, as described above, in the case of a nylon copolymer having triple shape memory effects prepared according to an embodiment of the present invention, a shape may be deformed, fixed, and recovered through two steps, thereby remembering a triple shape, and also a shape recovery temperature may be easily controlled to a desired level by adjusting a content of a reactant. In addition, a bionylon having triple shape memory effects may be prepared by using a bio-based reactant, and thus may be applied in a wide range of fields such as aircraft, environment, medical field, etc., in addition to an electronics industry.

Hereinafter, the results of evaluating properties of the nylon copolymer prepared according to the embodiment of the present invention described above will be described.

In order to prepare a nylon copolymer according to an embodiment of the present invention, an itaconic acid solution and a diamine solution were prepared by dissolving itaconic acid and 1,10-diaminodecane, which is one of diamine-based monomers, in a solvent of ethanol, respectively. The itaconic acid solution and the 1,10-diaminodecane were added into a beaker at the same mol ratio and reacted at 60° C. for 30 minutes. The product generated by the reaction was dried in a vacuum oven at 50° C. for 12 hours to obtain a salt-type monomer, which was then subjected to a heating process, thereby preparing 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA), which is the amino acid containing the biomass-derived pyrrolidone group. The 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA), which is the amino acid containing the biomass-derived pyrrolidone group, and 11-aminoundecanoic acid (AUA), which is the α,ω-aliphatic amino acid, were added into a 250 ml reaction vessel by varying a mol ratio thereof, and reacted at 240° C. for two hours under a nitrogen (N2) atmosphere so as to prepare the nylon copolymer. The reaction was accompanied by stirring at a speed of 160 rpm. The mol ratio conditions of the ADPA and the AUA are shown in [Table 1] below.

TABLE 1ADPA:AUAClassificationmol ratioFirst Comparative Example0:1First Example2:8Second Example4:6Third Example5:5Fourth Example6:4Second Comparative Example8:2

FIGS.1and2are graphs showing the results of measurement with1H-NMR spectroscopy to explain a chemical bonding structure of a nylon copolymer prepared from an amino acid containing a biomass-derived pyrrolidone group prepared according to a third example (ADPA:AUA=5:5) of the present invention by varying a molar content as well as a first comparative example (ADPA:AUA=0:1) with respect to embodiments of the present invention.

Referring toFIG.1, a chemical bonding structure of nylon11 polymerized with 11-aminoundecanoic acid (AUA), which is an α,ω-aliphatic amino acid, was confirmed from the1H-NMR graph.

As can be understood fromFIG.2, a chemical bonding structure of a nylon copolymer polymerized with 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA), which is the amino acid containing the biomass-derived pyrrolidone group, and 11-aminoundecanoic acid (AUA), which is an α,ω-aliphatic amino acid, was confirmed from the1H-NMR graph.

From the results ofFIGS.1and2, it was confirmed that a structure of the pyrrolidone group in the nylon copolymer is clearly synthesized.

With respect to the nylon copolymer prepared by varying a mol ratio of the ADPA and the AUA, the phase transition temperature (glass transition temperature (Tg) and melting temperature (Tm)) of the nylon copolymer was measured at a heating rate of 10° C./min by using a differential scanning calorimetry (DSC) device. The measured values of the phase transition temperature (glass transition temperature (Tg) and melting temperature (Tm)) of the nylon copolymer prepared by varying the mol ratio of the ADPA and the AUA are shown in [Table 2] below.

TABLE 2ADPA:AUATmTgClassificationmol ratio(° C.)(° C.)First Comparative0:1188.445.3ExampleFirst Example2:8167.644.4Second Example4:6135.544.0Third Example5:5134.940.6Fourth Example6:4101.438.7Second Example8:2—37.4

[Table 2] shows the measurement results according to the first comparative example (ADPA:AUA=0:1), the second comparative example (ADPA:AUA=8:2), the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5) and the fourth example (ADPA:AUA=6:4).

As can be understood from [Table 2], it was confirmed that the nylon copolymer prepared according to the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5) and the fourth example (ADPA:AUA=6:4), in which a molar content of the amino acid containing the biomass-derived pyrrolidone group is 20% to 60%, have both phase transition temperatures (glass transition temperature (Tg) and melting temperature (Tm)). As such, in the case of having two phase transition temperatures, a phase may be fixed, deformed and recovered through two steps based on the two phase transition temperatures. In addition, as a molar content of the amino acid containing the biomass-derived pyrrolidone group increases, it was confirmed that the glass transition temperature (Tg) and the melting temperature (Tm) of the prepared nylon copolymer are different. Accordingly, it was confirmed that it is possible to prepare the nylon copolymer having triple shape memory effects, which may easily control a shape recovery temperature by adjusting a molar content of the amino acid containing the biomass-derived pyrrolidone group.

FIG.3is a graph showing the results of measurement with dynamic mechanical analysis (DMA) to explain a storage modulus of a nylon copolymer prepared by varying a molar content of amino acid containing a biomass-derived pyrrolidone group prepared according to an embodiment of the present invention.

Referring toFIG.3, the nylon copolymer was prepared by the same method as described above by varying a molar content of 1-(10-aminodecyl)-2-pyrrolidone-4-carboxylic acid (ADPA), which is an amino acid containing a biomass-derived pyrrolidone group, prepared according to an embodiment of the present invention, and 11-aminoundecanoic acid (AUA), which is an α,ω-aliphatic amino acid. The mol ratio conditions of the ADPA and the AUA are as shown in above <Table 1>.

With respect to the nylon copolymer prepared by varying a mol ratio of the ADPA and the AUA, a storage modulus according to a temperature change was measured at a heating rate of 10° C./min with respect to the nylon copolymer prepared by using a dynamic mechanical analysis (DMA) device. The measured values of the storage modulus of the nylon copolymer prepared by varying a mol ratio of the ADPA and the AUA are as shown in [Table 3] below.

TABLE 3E′ atE′ atE′ atADPA:AUA30° C.50° C.150° C.Classificationmol ratio(MPa)(MPa)(MPa)First Comparative0:11200530160ExampleFirst Example2:8118040027Second Example4:614005000.4Third Example5:57501200.4Fourth Example6:4830800.6Second Comparative8:228050.7Example

FIG.3shows the measurement results of storage modulus according to the first comparative example (ADPA:AUA=0:1), the second comparative example (ADPA:AUA=8:2), the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5) and the fourth example (ADPA:AUA=6:4).

Referring toFIG.3, in the case of the nylon copolymer prepared according to the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5) and the fourth example (ADPA:AUA=6:4), in which a molar content of the amino acid containing the biomass-derived pyrrolidone group is 20% to 60%, it was confirmed that based on the two phase transition temperatures (the glass transition temperature (Tg) and the melting temperature (Tm)), the nylon copolymer may have a glass state section at the glass transition temperature (Tg) or lower, a rubbery state section between the glass transition temperature (Tg) and the melting temperature (Tm), and a melt state section at the melting temperature (Tm) or higher, in which a storage modulus is drastically changed and the storage modulus is constantly maintained in the melt state section at the melting temperature or higher. Accordingly, it could be understood that a shape may be fixed, deformed and recovered through two steps based on the two phase transition temperatures. Accordingly, it was confirmed that it is possible to prepare the nylon copolymer having triple shape memory effects, which may easily control a shape recovery temperature by adjusting a molar content of the amino acid containing the biomass-derived pyrrolidone group.

In contrast, in the case of the nylon prepared according to the first comparative example (ADPA:AUA=0:1) in which a molar content of the amino acid containing the biomass-derived pyrrolidone group is less than 20%, it was confirmed that there are a melting temperature (Tm) and a glass transition temperature (Tg), but there is no storage modulus in a melt state section at the melt temperature (Tm) or higher. Accordingly, if a molar content of the amino acid containing the biomass-derived pyrrolidone group is less than 20%, it was confirmed that there is no storage modulus in the melt state section, thus failing to express the triple shape memory effects. In addition, in the case of the nylon copolymer prepared according to the second comparative example, in which a molar content of the amino acid containing the biomass-derived pyrrolidone group is more than 60%, it was confirmed that there is no melting temperature (Tm). Accordingly, if a molar content of the amino acid containing the biomass-derived pyrrolidone group is more than 60%, it was confirmed that there are not two phase transition temperatures, thus failing to express the triple shape memory effects. Thus, it can be understood that using the amino acid containing the biomass-derived pyrrolidone group having a molar content of 20% to 60% is an efficient method for preparing a nylon copolymer having triple shape memory effects.

FIG.4shows experimental images on the triple memory properties of the first example out of the nylon copolymers prepared according to the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5), and example 4 (ADPA:AUA=6:4), which are prepared by the same method as described below.

Referring toFIG.4, it was confirmed that the nylon copolymer having a film form which is an initial shape (A) prepared according to the first example (ADPA:AUA=2:8) of the present invention maintains the primarily deformed shape (B) even after the nylon copolymer is heated at 167.6° C. or higher, which is the melting temperature (Tm) of the first example shown in above [Table 2] to apply the primary deformation, and then cooled down to around 44.4° C., which is the glass transition temperature (Tg) of the first example shown in above [Table 2], and the external force having maintaining the primary deformation is removed. Then, it was confirmed that the secondarily deformed shape (C) is maintained even after a sample is heated around 44.4° C., which is the glass transition temperature (Tg) of the first example shown in above [Table 2] to apply the secondary deformation, and then cooled down to a room temperature of 25° C., and the force having maintained the primary deformation is removed. In addition, it was confirmed that when the nylon copolymer having the secondarily deformed shape (C) is again heated around 44.4° C., which is the glass transition temperature (Tg) of the first example shown in above [Table 2], the shape is restored to the primarily deformed shape (B), and when the nylon copolymer is again heated at 167.6° C. or higher, which is the melting temperature (Tm) of the first example shown in above [Table 2], the nylon polymer is restored to have a film form, which is the initial shape (A).

As described above in the first example, it was confirmed that the nylon copolymer having a film form which is an initial shape (A) prepared according to the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5) and the fourth example (ADPA:AUA=6:4) of the present invention maintains the primarily deformed shape (B) even after the nylon copolymer is heated at the melting temperature (Tm) or higher of each example shown in above [Table 2] to apply the primary deformation, and then cooled down to around the glass transition temperature (Tg) of each example shown in above [Table 2], and the external force having maintaining the primary deformation is removed. Then, it was confirmed that the secondarily deformed shape (C) is maintained even after a sample is heated around the glass transition temperature (Tg) of each example shown in above [Table 2] to apply the secondary deformation, and then cooled down to a room temperature of 25° C., and the force having maintained the primary deformation is removed. In addition, it was confirmed that when the nylon copolymer having the secondarily deformed shape (C) is again heated around the glass transition temperature (Tg) of each example shown in above [Table 2], the shape is restored to the primarily deformed shape (B), and when the nylon copolymer is again heated at the melting temperature (Tm) or higher of each example shown in above [Table 2], the nylon polymer is restored to have a film form, which is the initial shape (A).

In order to evaluate the mechanical properties of the nylon copolymer prepared according to the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5), and the fourth example (ADPA:AUA=6:4) of the present invention, tensile strength and tensile elongation were measured. The tensile strength (MPa) and the tensile elongation (%) were measured repeatedly five times at a strain rate of 50 mm/min at room temperature by using a universal testing machine (UTM), and then an average value thereof was calculated. The calculated values of tensile strength (MPa) and tensile elongation (%) are as shown in [Table 4] below.

TABLE 4PropertiesTensileTensile100%ADPA:AUAstrengthelongationmodulusClassificationmol ratio(MPa)(%)(MPa)First Example2:85338035Second Example4:65338527Third Example5:55040024Fourth Example6:44438522

Referring to [Table 4], it was confirmed that the nylon copolymer prepared according to the first example (ADPA:AUA=2:8), the second example (ADPA:AUA=4:6), the third example (ADPA:AUA=5:5), and the fourth example (ADPA:AUA=6:4) of the present invention has excellent mechanical properties and is capable of adjusting the values of tensile strength (MPa) and tensile elongation (%) as a molar content of amino acid containing the biomass-derived pyrrolidone group is changed. Accordingly, it was confirmed that the mechanical properties of the nylon copolymer prepared according to a molar content of the amino acid containing the biomass-derived pyrrolidone group may be easily adjustable.

A nylon copolymer having triple shape memory effects according to an embodiment of the present invention is a bio-based nylon which is eco-friendly, remembers a triple shape, and is also capable of controlling a shape recovery temperature to a desired level, and thus is applicable to a wide range of fields such as a medical field, actuators, aircrafts, automobiles, an electronic industry, etc.