KR20140136830A - N,O-Hydroxypropyl Chitosans and their alkanoic acid esters for liquid crystal and method for manufacturing the same - Google Patents

Abstract

The present invention relates to an N,O-hydroxypropyl chitosan forming a thermotropic cholesteric phase, fatty acid esters thereof, and a manufacturing method thereof. The present invention provides a material for a thermotropic liquid crystal in which thermal stability of a cholesteric phase, a range of forming temperatures, and temperature dependency of an optical pitch are controlled by the N,O-hydroxypropyl chitosan esters obtained where the degree of substitution of N,O-hydroxypropyl chitosan changes the degree of molar substitution and carbon numbers of a substitute group introduced in the N,O-hydroxypropyl chitosan.

Description

[0001] N, O-Hydroxypropyl Chitosan and their Fatty Acid Esters for Liquid Crystals and their Production Processes [0002] N, O-Hydroxypropyl Chitosans and Their Alkanoic Acid Esters for Liquid Crystals and Methods for Manufacturing the Same [

The present invention relates to a chitosan-derived fatty acid ester and a process for producing the chitosan-derived fatty acid ester. More particularly, the present invention relates to N, O-hydroxypropyl chitosan (HPCTO) for liquid crystals and fatty acid esters thereof, will be.

Liquid crystals (LCs) with anisotropy of crystals and intermediate order (or symmetry) of isotropic liquids are divided into two types. First, it is a liquid crystal formed by a pure compound or a mixture of compounds in a molten state. The liquid crystal phase that they form is called a thermotropic LC since it is formed by a temperature change. In addition, since the phase transition to the liquid crystal-isotropic liquid with the crystal-diverse molecular arrangement of these materials is caused by the temperature change, these liquid crystal materials are also called thermotropic phase transition LCs. The second is the liquid crystal material formed by the binary or multicomponent solution and is called the lyotropic LC. Also, the phase transition to a liquid crystal phase with an isotropic liquid-diverse molecular arrangement represented by these materials is also referred to as a lyotropic phase transition LC because it occurs not only by temperature but also by a change in solute concentration.

Liquid crystals are classified into smectic, nematic, and cholesteric or chiral nematic liquid crystals depending on the arrangement of molecules. Unlike other liquid crystal materials, cholesteric liquid crystal materials in which pseudonematic layers form a periodic spiral structure have unusual optical properties such as selective reflection by circular polarization, angle dependence of reflection wavelength, It can be utilized as various materials such as flat panel displays, color information, organic pigments, optical filters, laser generation, optical switches, temperature sensors and the like. In order to utilize the cholesteric material for this purpose, not only the film forming ability is good but also the glass transition temperature (T _g ), the thermal stability of the liquid crystal, the formation temperature range and the optical pitch (λ _m ) It is required to establish a manufacturing method of a thermotropic cholesteric substance having controlled temperature dependency.

Chitosan is a mucopolysaccharide having a structure having -NH ₂ in addition to two OH groups in the pyranose ring and can be obtained by deacetylation of chitin. Chitosan has been widely used in various fields such as antibacterial fibers, natural preservatives, food additives, cosmetics, wastewater treatment, medical materials, and liquid crystal materials.

A study on the thermotropic cholesteric liquid crystal characterization using chitosan derivatives was conducted for the very first time. The thermotropic and liquid crystalline behavior of HPCTOs, and Polymer (Korea), Vol. 36, p 380 to 392 (2012).

This study examines the thermal properties of four types of HPCTOs with degrees of substitution (DS) and molar substitution (MS) ranging from 2.47 to 2.52 and 4.9 to 7.8, respectively. The thermal stability on the steric and the temperature dependence of the optical pitch are suggested by the control of DS and MS of HPCTO. However, the disadvantage of this technique is that the glass transition temperature, the cholesteric phase temperature range, the thermal stability and the temperature dependence of the optical pitch are still limited, as well as the way of broadly controlling the DS and MS of HPCTO.

Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide HPCTOs which can widely control T _g , thermal stability and temperature dependence of? _{M in} the conventional thermotropic cholesteric phase, The present invention is directed to a method of manufacturing a semiconductor device.

One aspect of the present invention provides a process for preparing HPCTO having DS = 2.15 ~ 2.39 and MS = 2.9 ~ 4.1 obtained by reacting chitosan and propylene oxide.

Another aspect of the present invention to solve the above problems is to provide a process for producing a thermosetting polyolefin resin composition which comprises reacting HPCTO and alkanoic acid chloride (COCl (CH ₂ ) _m CH ₃ , m = 0 to 9) To provide HPCTO fatty acid esters that form a steric phase.

The method of producing HPCTO and HPCTO fatty acid esters for forming a thermotropic cholesteric phase according to the present invention can provide a method for producing a thermotropic cholesteric liquid crystal material having different thermal and optical properties on a cholesteric phase.

FIG. 1 shows a process for synthesizing HPCTO fatty acid ester according to the present invention.
2 is a graph showing the FTIR spectra of chitosan and HPCTO and HPCTO fatty acid esters according to Preparation Examples 1, 2, 3, 5, 7, 9 and 11 of the present invention.
3 is a graph showing ¹ H NMR spectra of HPCTO and HPCTO fatty acid esters according to Preparation Examples 1, 2, 3, 5, 7, 9 and 11 of the present invention.
FIG. 4 is a graph showing ¹³ C-cross-polarization / magnetic angle spinning (CP / MAS) -NMR spectra of solid state of chitosan and ¹³ C NMR spectra of HPCTO according to Preparation Examples 1 and 2 of the present invention.
Figure 5 is a photograph of optical tissue observed in the production examples of the present invention.
6 is DSC thermal curves of HPCTO and HPCTO fatty acid esters according to Preparation Examples 1 to 12 of the present invention.
Figure 7 is a graph showing the transition temperatures of HPC fatty acid esters (HPCAm) and the HPCTO fatty acid esters according to Preparations 3-12 of the present invention as a function of m + 2.
8 is a graph showing the positions of the average absorption bands of NH and C = O as a function of temperature.
FIG. 9 is a UV-Vis reflection spectral graph of Production Examples 2, 4, 7 and 12 of the present invention. FIG.
10 is a graph showing the temperature dependence of? _M or? _M- ¹ in HPCAm and Production Examples 2 to 12 of the present invention.
11 is an X-ray diffraction graph of HPCTO (MS = 7.8, DS = 2.52) and Production Examples 2 to 12 according to the comparative example.
12 is a graph showing the relationship between the temperature of the HPCTO (MS = 7.8, DS = 2.52) according to the comparative example and the production examples 2, 3, 5 and 7 to 12 of the present invention and the distance d between the similar nematic layers to be.
Fig. 13 is a graph showing the results of comparison between the HPCTO (MS = 7.8, DS = 2.52) according to the comparative example and the cholesteric (P / d) of the similar nematic layers forming the twist angle (q) and 1 pitch (p) between the similar nematic layers.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the present invention is not limited to the embodiments described herein but may be embodied in other forms and includes all equivalents and alternatives falling within the spirit and scope of the present invention.

The terms used in the specification and claims should not be construed to be limited to ordinary or dictionary terms and the inventor may, in accordance with the principle of properly defining the concept of terms to describe his invention, It should be interpreted in terms of meaning and concept consistent with technical thought.

As used herein, the term "ambient temperature" means 15 deg. C to 25 deg. As used herein, the term "DS" means the number of OH and NH substituted in the two OH groups and two NH groups present per glucosamine unit.

As used herein, the term "MS " means the number of moles of propylene oxide introduced per glucosamine unit.

The HPCTO fatty acid ester of the present invention is produced by combining O or N present in HPCTO with (-CO (CH ₂ ) _m CH ₃ ).

≪ Production of HPCTO &

The chitosan chain obtained by deacetylation of chitin, which can be obtained from natural shellfish crust, which is rich in cellulose crust, has chiral nature and is more rigid than cellulose. Unlike cellulose, chitosan has an NH ₂ group at the C-2 position of the pyranose ring. The HPCTO used in the present invention is prepared by reacting chitosan and propylene oxide. The DS and MS of HPCTO can be controlled by varying the molar number of propylene oxide or NaOH and the reaction pressure to 1 mol of glucosamine units.

≪ Preparation of HPCTO fatty acid ester &

The HPCTO fatty acid ester can be synthesized by reacting HPCTO with alkanoic acid chloride (ClOC (CH ₂ ) _m CH _3, m = 0 to 9).

FIG. 1 shows the synthesis of a fatty acid ester of HPCTO having DS = 2.5 and MS = 3.5. It can be seen that an OH or NH group present in HPCTO reacts with an alkanoic acid chloride to form an HPCTO fatty acid ester.

Hereinafter, preferred examples for the understanding of the present invention will be described. It should be understood, however, that the following examples are intended to aid in the understanding of the present invention and are not intended to limit the scope of the present invention.

< HPCTO of Production Examples >

Sodium hydroxide (NaOH) powder with a weight ratio of 1: 10: 1.4 of chitosan: 2-methyl-2-propanol: H ₂ O was added and stirred at room temperature for 1 hour. Thereafter, filter cake was recovered by filtration, and the weight of the alkali chitosan was about three times that of chitosan. After the alkaline chitosan, propylene oxide and hexane were fed into the pressure reactor, the reaction was stirred at 70 ° C for 16 hours under pressure at a pressure of 30 bar. The weight ratio of chitosan and hexane was 1: 9.5. After completion of the reaction, the product recovered by filtration was gradually introduced into a large amount of hot water. To the solution H ₃ PO ₄ An aqueous solution (85 wt%) was added to bring the pH to 7, and the solution was left in hot water (85-95 ° C). Most of the water was removed by tilting and the product obtained was dissolved in a large amount of water at room temperature. The aqueous solution recovered by filtration was precipitated in hot water, tilted, dissolved in water at room temperature, and filtrated repeatedly for 10 times. A solution obtained by dissolving a sample treated with water 10 times in water and formic acid was gradually added dropwise to a large amount of cyclohexane. The solution was stirred for about 3 hours, and the precipitate recovered by filtration was repeated 5-6 times with formic acid and cyclohexane. The recovered precipitate was dried under reduced pressure at 130 DEG C for 48 hours. The products were white solid at room temperature and did not contain Na ions. The DS and MS of HPCTO were controlled as shown in the following table by varying the number of moles of propylene oxide and sodium hydroxide per mole of glucosamine unit, and two types of HPCTO obtained by different reaction conditions were substituted with HPCTOn (n = 1, 2) (See Table 1).

<Comparative Example>

The same procedure as in the HPCTO preparation example was carried out except that the mole number of propylene oxide and sodium hydroxide per 1 mole of glucosamine unit was adjusted as shown in Table 1 to obtain HPCTO having MS of 7.8 and DS of 2.52.

Classification

Reaction pressure (bar) MS DS M _n 10 ^-4 M _w / M _n Production Example 1
(HPCTO1) 0.6 10 30 2.9 2.15 12.1 2.08 Production Example 2
(HPCTO2) 0.8 15 30 4.1 2.39 14.4 2.14 Comparative Example 3.24 80 30 7.8 2.52 15.9 2.50

: The number of moles of sodium hydroxide per mole of glucosamine (GlcN) units of HPCTO,

MS: molar substitution degree, DS: degree of substitution, M _n : number average molecular weight measured by GPC, M _w : weight average molecular weight measured by GPC (molecular weight measured by gel permeation chromatography

< HPCTO  Fatty acid ester Production Examples >

To a mixed solvent of 1,3-dioxane (20 ml) and pyridine (2 ml), 1 g of HPCTO and 1 g of ClOC (CH ₂ ) _m CH ₃ (m = 0, 2) corresponding to 6 moles of moles of glucose units of HPCTO , 4, 7, 9) were injected and refluxed at a temperature of 110 ° C for 24 hours. The reaction product was poured into a large amount of water at room temperature and stirred for 12 hours. The precipitate recovered by filtration was dissolved in acetone. The acetone solution obtained by filtration was poured into a large amount of hot water (85-95 ° C). The precipitate recovered by filtration was repeatedly treated with water, acetone and hot water at room temperature, and the resulting product was dried under reduced pressure at a temperature of 60 DEG C for 48 hours. The fatty acid esters of HPCTOn (n = 1,2) prepared in Preparation Examples 1 and 2 were named HPCTO1Am (m = 0, 2, 4, 7 and 9), HPCTO2Am (m = 9).

n m Production Example 3 (HPCTO1A0) One 0 Production Example 4 (HPCTO1A2) One 2 Production Example 5 (HPCTO1A4) One 4 Preparation Example 6 (HPCTO1A7) One 7 Preparation Example 7 (HPCTO1A9) One 9 Production Example 8 (HPCTO2A0) 2 0 Production Example 9 (HPCTO2A2) 2 2 Production Example 10 (HPCTO2A4) 2 4 Preparation Example 11 (HPCTO2A7) 2 7 Production Example 12 (HPCTO2A9) 2 9

<Properties of Composites Analysis Example 1   Product Analysis>

¹ H NMR (CDCl ₃₎ solution obtained by measurement at room temperature using FTIR (Thermo-Nicolet, YS-10) spectrum obtained by attenuated total reflection and tetramethylsilane (TMS) with (400MHz, Varian VNMR-400NB) spectrum and the CDCl ₃ solution ¹³ obtained by measuring at 40 ℃ using (7 wt%) C NMR ( Varian VNMR-600NB) a HPCTO synthesized in Preparative example analyzes the spectrum HPCTO fatty acid esters. The ¹³ C NMR spectrum of chitosan was obtained by solid state ¹³ C-CP / MAS-NMR spectroscopy. ¹³ C-CP / MAS-NMR spectra were recorded at room temperature using a 300 MHz Varian Mercury Plus spectrometer.

<Properties of Composites Analysis example 2   Molecular Characterization Analysis>

The content of Na ions in HPCTO was measured using ICP-MS (Perkin-Elmer NEXION). The optical structure of the thermotropic liquid crystal phase was observed with a polarizing microscope (Olympus BH-2, Japan) equipped with a heating plate (Metter, FP-82 HT) and a temperature controller (FP-90, Switzerland).

The enthalpy change (ΔH) at the phase transition was evaluated by the heat curve of a differential scanning calorimeter (DSC; Mettler 822e) obtained by measuring the heating and cooling rate at 5 ° C./min under a nitrogen stream.

The average molecular weight of HPCTO was assessed by gel permeation chromatography (GPC; Agilent Infinity 1260). Tetrahydrofuran was used as the eluent and the flow rate was maintained at 1 mL / min. The calibration curve was generated using a standard polystyrene solution in tetrahydrofuran

Collet λ _m on the cholesteric was determined by the maximum of the reflection wavelength of the UV / Vis / NIR spectrophotometer (UV / Vis / NIR spectrophotometer, Perkin-Elmer Lambda 950) spectrum. A sample was injected into a square cell obtained by bonding a polyimide film having a thickness of about 10 mu m to a glass plate with an epoxy resin, and then heated to melt the sample. The cell thus prepared was covered with a cover glass plate and bonded with an epoxy resin. The cell was fixed to a heating plate and allowed to stand for about 36 hours at the temperature at which the? _M of the thermotropic cholesteric phase was to be measured. Reflected spectra were measured by irradiating light to a sample in a nearly uniform planar texture obtained by pressing the oriented sample. The average refractive index of the cholesteric phase was measured using a UV / Vis / NIR spectrophotometer (Perkin-Elmer Lambda 950) equipped with a temperature controller and a 150 mm integrating sphere.

The X-ray diffraction pattern of the samples was recorded by Ultima IV (Rigaku) diffractometer equipped with Ni-filter. The diffraction pattern of the equatorial line was recorded at 2θ in the range of 5 to 30 ° using Cu-Kα (1.5418 Å) radiation generated at 40 kV and 40 mA. The specimen inserted between the glass plates having a thickness of 0.1 mm was heated to a temperature not lower than the transition temperature to the liquid phase on the liquid crystal, cooled and allowed to stand at the temperature to be measured for 12 hours, and fixed to a diffractometer equipped with a temperature controller, Ray diffraction pattern was measured.

Figure 2 is a graph showing the FTIR spectra of chitosan and HPCTO and HPCTO fatty acid esters according to Preparation Examples 1, 2, 3, 5, 7, 9 and 11 of the present invention, 1, a graph embellish appear 2, 3, 5, 7, 9, and HPCTO and ¹ H NMR spectra of HPCTO fatty acid ester according to 11.

(HPCTO1), (c), (d), (d) and (e) are shown in Production Example 2 (HPCTO2) (HPCTO1A4), (f), and (h) show the FTIR spectra of Production Example 7 (HPCTO1A9), Production Example 9 (HPCTO2A2) and Production Example 11 (HPCTO2A7).

Unlike chitosan, the absorption intensity due to the stretching vibration (around 3500 cm ^-1 ) of the hydroxy group (-OH) and the bending vibration (1585 ~ 1605 cm ^-1 ) of NH ₂ decreases in the case of HPCTOn while the CH ₃ and CH ₂ The ratio of asymmetry (2973 ~ 2985cm ^-1 ) and absorption intensity by symmetry (2876 ~ 2882cm ^-1 ) stretching vibration tended to increase. On the other hand, unlike the case of HPCTOn HPCTO1Am and HPCTO2Am OH peak is not observed, new peaks due to the stretching vibration of NH (3300cm ^-1 vicinity) and C = O (-O) (1750 ~ 1780cm -1) of the ester was observed . Other HPCTO fatty acid esters exhibited the same FTIR spectra.

3 (HPCTO1A0), (d), and (e) of Production Example 5 (HPCTO1A4) and (e) of Production Example 1 (HPCTO1) manufacturing example 7 (HPCTO1A9), (f) the preparation 9 (HPCTO2A2), (g) is a graph that appears to embellish the ¹ H NMR spectra of Preparation 11 (HPCTO2A7).

In the case of HPCTOn, CH ₃ (0.9 to 1.4 ppm), OH (2 ppm), CH ₂ (2.8 ppm) adjacent to N when hydroxypropyl groups are introduced at the H and N positions of the C-2 carbon, Peaks due to CH ₂ and CH (3.0-4.2 ppm) and NH (5.7 ppm) in the ternary pyranose ring were observed. MS values of the HPCTOn evaluated using the area between 0.9 and 1.4 ppm and the area of the characteristic peaks (2, 2.8, 3.0 to 4.2 and 5.7 ppm) except for this were shown in Table 1. Unlike in HPCTOn HPCTO1Am and HPCTO2Am is OH peak is not observed a peak due to the terminal CH ₃ of the propylene oxide groups were divided, into three (1.14 ~ 1.25, 1.44 ~ 1.47 , 1.57 ~ 1.63 ppm). This is thought to be due to the fact that the CH ₃ chemical environment of the whole molecule is not equal due to the difference in degree of branches (distribution of MS) of propylene oxide in HPCTO. On the other hand, in the HPCTOnAm - it was observed in the 4.7 ~ 4.9 ppm a peak attributed to their respective, 2.25 ~ 2.18 ppm and 1.81 ~ 1.75 ppm - CH OCO-, -CHOCO CH 2 - and CH ₂ CHOCOCH _2. The peaks of all other hydrogens except for these peaks were observed in the range of 3.0 to 4.2 ppm. Other HPCTO1Am and HPCTO2Am also showed the same ¹ H NMR spectra.

As a result, FTIR and ¹ H NMR analysis show that HPCTOnAm can be a chitosan derivative having three esterifications of 3 in only one OH group existing in HPCTOn and one of two NH groups existing in chitosan.

4 is a graph showing ¹³ C-NMR spectra of ¹³ C-CP / MAS spectra of chitosan and HPCTO according to Production Examples 1 and 2 of the present invention.

4 (a) is a graph showing the ¹³ C NMR spectra of the chitosan, (b) is the production example 1 (HPCTO1), and (c) is the production example 2 (HPCTO2).

The resonance of the carbon linked to the etherified OH group present in the cellulose or chitin chain is shifted to a lower magnetic field than the resonance of the carbon connected to the unsubstituted OH group. Considering this fact and the fact that the peaks attributed to the unsubstituted C-2, C-3 and C-6 carbons in the chitosan chain are observed at 61.5, 74.5 and 62.4 ppm, respectively, 61.8 to 61.9, 75.2 To 75.5 and 63.1 to 63.3 ppm are expected to be peaks due to substituted C-2 carbon (C-2S), C-3 carbon (C-3S) and C-6 carbon . On the other hand, pyrano addition to the carbon present in a ring agarose p (76.5 ~ 78.2ppm), ( Ⅰ) (21.30 ~ 21.55ppm) and (Ⅱ) in CH ₂ (19.05 ~ 19.20ppm) of the peaks are, respectively, hydroxy propyl And CH, the CH ₃ in the terminal hydroxypropyl group, and the CH ₃ carbon in the internal hydroxypropyl group. The DS values of HPCTOn evaluated using the MS value of HPCTO and the area ratio of (I) peak to (II) peak are shown in Table 1.

In conclusion, it can be seen that the MS and DS ranges of HPCTO can be controlled by adjusting the pressure, temperature and time of the reaction and by adjusting the molar ratio of NaOH to propylene oxide to the glucosamine unit.

Figure 5 is a photograph of optical tissue observed in the production examples of the present invention.

HPCTO1Am (m = 0, 2, 4) and HPCTO2Am (m = 0, 2) are white solid at room temperature while HPCTO1Am (m = HPCTO2Am (m = 4, 7, 9)) exhibited a bubble property as a viscous liquid phase substance at room temperature. All the derivatives prepared by the present invention formed a biaxial liquid crystal phase. 5 (a) to 5 (o) show optical structures observed by a polarization microscope when samples are heated to be in an isotropic liquid state and then cooled.

(a) Production Example 1 (HPCTO1, 210 占 폚); (b) tissue (a) when stress is applied to the tissue (HPCTO1, 210 占 폚); (c) Production Example 2 (HPCTO2, 170 DEG C); (d) Production Example 2 (HPCTO2, 95 DEG C); (e) Production Example 3 (HPCTO1A0, 150 占 폚); (f) Preparation Example 3 (HPCTO1A0, 110 占 폚); (g) Production Example 4 (HPCTO1A2, 80 DEG C); (h) Production Example 4 (HPCTO1A2, 60 DEG C); (i) Production Example 5 (HPCTO1A4. 150 占 폚); (j) Production Example 5 (HPCTO1A4, 130 占 폚); (k) Preparation Example 7 (HPCTO1A9, 110 占 폚); (l) Preparation Example 7 (HPCTO1A9, 30 占 폚); (m) Preparation 8 (HPCTO2A0, 130 [deg.] C); (n) Production Example 10 (HPCTO2A4, 25 캜); (o) Preparation 12 (HPCTO2A9, 25 [deg.] C).

HPCTO1 forms a polygonal structure (a) at a temperature range of about 200 to 215 캜, and the structure (a) changed to a planar structure (b) by stress. When the sample was slowly cooled, the tissue (a) changed to a solid phase at a temperature of about 198 ° C. Unlike HPCTO1, HPCTO2 formed fingerprint tissue (c) at high temperature, while focal-conic tissue (d) at low temperature. (F), (g), (j), (f), and (f) at higher temperatures depending on the temperature. , (l) or (n)), and at low temperatures the liquid phase changed to a solid phase (see (h)).

6 is DSC thermal curves of HPCTO and HPCTO fatty acid esters according to Preparation Examples 1 to 12 of the present invention.

For all specimens except HPCTO1, the thermal changes of T _g and cholesteric to liquid phase (T _Ci ) were observed in the temperature range of -5 ~ 36 ℃ and 115 ~ 185 ℃, respectively . On the other hand, when the samples were cooled, the transition temperature (T _iC ) from the liquid to the cholesteric phase and the thermal change determined as T _g were observed in the temperature range of 113 to 183 ° C and -7 to 36 ° C, respectively. For HPCTO1, the thermal change is determined in the same manner as the symptoms that are reported for the DSC thermal curve formed on HPC and derivatives thereof as the only T _g is observed in T or T _{iC Ci} was not observed. This is mainly due to the decrease of regularity of the liquid crystal phase due to the distribution of DS and MS due to the synthesis conditions of HPCTO and the decrease of the heat amount required for phase transition due to the distribution of T _ci or T _iC .

In conclusion, the observation of the polarizing microscope and the results of the DSC measurement show that HPCTOn, HPCTO1Am and HPCTO2Am form a biaxial cholesteric phase.

The transition temperatures and? H values of HPCTOn, HPCTO1Am and HPCTO2Am determined by observation of DSC thermal curves and polarization microscope according to Production Examples 1 to 12 of the present invention are shown in Table 3 below.

Classification heating Cooling T _g (° C) T _ci (캜)
[? H, J / g] T _ic (° C)
[? H, J / g] T _s (° C) T _g (° C) Production Example 1 41 ~ 220 ~ 215 ~ 198 39 Production Example 2 29 185 [1.42] 183 [1.39] ~ 85 27 Production Example 3 36 180 [1.31] 178 [1.29] ~ 101 36 Production Example 4 32 171 [1.53] 169 [1.50] ~ 67 30 Production Example 5 26 164 [1.72] 161 [1.70] ~ 40 23 Production Example 6 20 151 [1.98] 148 [1.95] 24 19 Production Example 7 15 140 [2.12] 136 [2.08] ~ 18 13 Production Example 8 22 163 [1.30] 161 [1.29] ~ 69 20 Production Example 9 15 154 [1.47] 151 [1.41] ~ 47 14 Production Example 10 10 149 [1.63] 145 [1.57] ~ 25 8 Production Example 11 6 131 [1.85] 130 [1.81] ~ 11 3 Production Example 12 -5 115 [1.99] 113 [1.90] ~ 5 -7 T _g = Glass transition temperature, T _Ci = transition temperature from cholesteric phase to liquid phase, T _iC = transition temperature from liquid phase to cholesteric phase, T _s = transition temperature from cholesteric phase to solid phase

Figure 7 is a graph showing the transition temperatures of HPC fatty acid esters (HPCAm) and the HPCTO fatty acid esters according to Preparations 3-12 of the present invention as a function of m + 2.

HPCTO1Am, HPCTO2Am and HPC (Aldrich Co., M _w = 10 ⁵⁾ of the transition temperature reported for HPCAm (m = 0,1 ~ 5,8) in a degree of ester is 2.59 ~ 2.83 scope synthesized using HPCTO or (M + 2) in the substituent introduced into the HPC.

220℃에 비해 HPCTO1Am의 T_g와 T_Ci는 낮으며 HPCAm이 나타내는 현상과 유사하게 m+2가 증가함에 따라 낮아지는 경향을 나타낸다. HPCTO2의 T_g=29℃ 그리고 T_Ci=185℃에 비해 HPCTO2Am의 T_g와 T_Ci는 낮으며 m+2가 증가함에 따라 낮아지는 경향을 나타낸다. 이러한 사실은 주로 수소결합력 감소와 HPCTOn에 도입된 알킬기의 길이의 증가에 의한 곁사슬기들의 충진밀도의 감소(자유체적의 증가)에 따른 주사슬의 가소화(internal plasticization)에 의해 나타나는 것으로 생각된다. 한편, m+2가 동일할 경우, HPCTO1Am의 T_g와 T_Ci에 비해 HPCTO2Am의 T_g와 T_Ci가 낮은 사실은 HPCTO의 MS의 증가로 인한 주사슬의 가소화로 의해 초래되는 반면 HPCTO1Am과 HPCTO2Am T_g와 T_Ci가 HPCAm의 T_g와 T_Ci에 비해 높은 것은 주로 HPCTO 중에 존재하는 NH에 기인한 NH간 및 NH와 C=O간의 작용하는 분자간 혹은 분자내의 수소결합력에 의해 콜레스테릭 상의 열적 안정성이 증가하며 주사슬의 세그멘트 운동이 억제되는 사실로부터 초래되는 것으로 생각된다(아래 도 8 참고).HPCTO1's T _g = 41 ° C and T _Ci

Compared to 220 ° C, T _g and T _ci of HPCTO1Am are low and tend to decrease as m + 2 increases, similar to the phenomenon indicated by HPCAm. Was HPCTO2 of T _g = 29 ℃ and T = _Ci HPCTO2Am the T _g and T _Ci than 185 ℃ is low, tends to be lowered as the m + 2 is increased. This is probably due to the internal plasticization of the main chain due to the decrease in the hydrogen bonding force and the decrease in the packing density of the side chain groups (increase in the free volume) due to the increase in the length of the alkyl groups introduced into HPCTOn. On the other hand, when m + 2 is the same, the fact that the T _g and T _ci of HPCTO2Am are lower than the T _g and T _ci of HPCTO1Am are caused by plasticization of the main chain due to the increase of MS of HPCTO, whereas HPCTO1Am and HPCTO2Am T _g and T _Ci is the thermal stability of the cholesteric by hydrogen bonding in the molecules, or molecules that act between HPCAm the T _g and T liver is higher than the _Ci NH mainly due to NH present in HPCTO and NH and C = O Is increased and the segment movement of the main chain is suppressed (see FIG. 8 below).

HPCTO1Am and HPCTO2Am the △ H values shown in the T _Ci [Table 3] an entropy change at T _Ci is evaluated using (△ S) are respectively 2.07 ~ 5.60 J / K · mol -glucosamine unit and 2.69 ~ 6.31 J / K · It is in the range of mol-glucosamine unit, and ΔS tends to increase as m increases. On the other hand, when m is the same,? S tends to be larger in HPCTO2Am than HPCTO1Am. This fact is similar to the phenomenon that the conventional HPC and HPCTO exhibit ΔS represented by T _Ci as Tc increases with increasing MS. As the length of the substituent introduced into chitosan increases, the substituent shifts from the suppression of the cyclic skeleton to the cholesteric phase The degree of order of the molecular arrangement of the molecule increases.

Consequently, it can be seen that the order of the molecular arrangement on the cholesteric phase is increased by increasing the length of the substituent introduced into HPCTOn.

8 is a graph showing the positions of the average absorption bands of NH and C = O as a function of temperature.

The positions of the average absorption bands of NH and C = O observed in the FTIR spectra of HPCTO1Am and HPCTO2Am with m = 2,9 are shown as a function of temperature. It can be seen that when the temperature reaches T _Ci , the absorption bands of NH and C = O are shifted in the high frequency direction. This fact implies that the thermal stability of the cholesteric phase of the HPCTOnAm and the segment movement of the main chain are governed by the NH bond and the hydrogen bonding force between NH and C = O.

Fig. 9 is a UV-Vis reflection spectral graph of Production Examples 2, 4, 7 and 12 of the present invention.

(HPCTO1A2), (c), (c) and (d) are shown in Table 1 and Table 2, respectively. UV-Vis is a reflection spectra graph.

HPCTO1 was not able to obtain the UV-Vis reflection spectrum of HPCTO1 as a function of temperature because of high T _Ci . For example, in the case of HPCTO2, HPCTO1A2, HPCTO1A9 and HPCTO2A9, examples of UV-Vis spectra as a function of temperature obtained by cooling samples except HPCTO1 from temperatures above T _Ci are shown in FIG. The maximum reflected wave field of the UV-Vis spectrum increases with increasing temperature. Other samples showed the same trend. The mixture of HPC and HPCTOn or HPCTOnAm forming the cholesteric phase with rightward helical structure did not exhibit phase separation.

As a result, it can be seen that all derivatives synthesized in the present invention form cholesteric phases having a right-handed helical structure.

10 is a graph showing the temperature dependence of? _M or? _M- ¹ of HPCAm and Production Examples 3 to 12 of the present invention.

The temperature dependence of λ _m and λ _m ^-1 of HPCTO2, HPCTO1Am and HPCTO2Am determined by the maximum reflected wavelength of the UV-Vis spectrum are shown in (a) and (b), respectively. For comparison, the temperature dependence of λ _m and λ _m ^-1 of HPCAm (m = 0, 1, 2) is also shown. Similar to the HPC derivatives obtained by introducing various non mesogenic groups, there is a linear relationship between λ _m ^-1 and temperature of all derivatives. However, the decrease rate of? _M- ¹ due to the temperature rise of HPCAm and the production examples 2 to 12 of the present invention shows a phenomenon that the plate is changed.

), p 그리고 λ_m간에는 λ_m =

p 의 관계가 성립한다. 한편, d, q 그리고 p간에는 p=2πd/q의 관계가 성립한다.

, d, 및 q는 온도에 의존하며 이들의 온도의존성은 콜레스테릭 상을 형성하는 물질의 종류에 따라 달라진다.The average refractive index on the cholesteric phase (

), between p and lambda _m, lambda _m =

p is established. On the other hand, there is a relation p = 2πd / q between d, q and p.

, d, and q depend on temperature and their temperature dependence depends on the type of material forming the cholesteric phase.

의 온도의존성을 알아보기 위하여 본발명에 따른 제조예 2 내지 12의 HPCTO2, HPCTO1Am,및 HPCTO2Am을 이용하여 75℃, 110℃ 및 130℃에서 측정한

값들을 하기의 [표 4]에 나타냈다. _{Represented in} the range of T _s and T _iC

Were measured at 75 ° C, 110 ° C and 130 ° C using HPCTO2, HPCTO1Am and HPCTO2Am of Production Examples 2 to 12 according to the present invention

The values are shown in Table 4 below.

Classification

Average refractive index

75 ℃ 110 ° C 130 ℃ Production Example 2 1.472 1.471 Production Example 3 1.473 1.472 Production Example 4 1.474 1.472 1.471 Production Example 5 1.473 1.471 1.470 Production Example 6 1.472 1.470 1.469 Production Example 7 1.471 1.469 1.469 Production Example 8 1.473 1.471 1.470 Production Example 9 1.472 1.470 1.469 Production Example 10 1.472 1.470 1.468 Production Example 11 1.471 1.469 1.468 Production Example 12 1.470 1.468

값은 분자의 화학구조와 온도에 민감하게 의존하지 않으며 약 1.5로서 거의 일정한 경향을 나타냄을 알 수 있다.Referring to Table 4, all the derivatives

Value does not depend sensitively on the chemical structure and temperature of the molecule and is about 1.5, indicating a nearly constant tendency.

11 is an X-ray diffraction graph of HPCTO (MS = 7.8, DS = 2.52) and Production Examples 2 to 12 according to the comparative example.

11 (a) is an X-ray diffraction chart of HPCTO1Am, and FIG. 11 (c) is an X-ray diffraction chart of HPCTO2Am at a temperature of 110 DEG C in Production Example 2 (HPCTO2) and HPCTO (MS = 7.8, DS = 2.52).

Peaks widely distributed in the vicinity of 20 deg. Indicate peaks related to the average distance of adjacent chitosan chains in the amorphous state, and peaks in the vicinity of 5 to 7 deg. Indicate peaks related to the average distance (d) between adjacent similar nematic layers .

12 is a graph showing the relationship between the temperature and d of HPCTO (MS = 7.8, DS = 2.52) and Preparation Examples 2, 3, 5 and 7 to 12 according to the comparative example.

값들은 약 1.5로 거의 일정하고 열팽창에 의한 d의 증가율은 대단히 작은 사실을 고려할 때, HPCAm, HPCTO2, HPCTO1Am 그리고 HPCTO2Am의 온도상승에 의한 λ_m의 증가율이 다른 것은(도 10 참고) 주로 온도상승에 의한 분자들의 입체형태(conformation)의 변화에 기인한 유사네마틱 층에 존재하는 셀룰로오스 혹은 키토산 사슬간의 상호작용에 의해 초래되는 q의 감소율의 차이 때문인 것으로 사료된다.The increase rate of d due to temperature rise of HPCTO shows a tendency to increase with increasing MS. On the other hand, the increase rate of d due to the temperature increase of HPCTO1Am and HPCTO2Am shows a tendency to increase as the number of carbon atoms of the substituent introduced into HPCTO increases. However, the thermal expansion coefficient (dlnd / dT) of the preparation examples of the present invention is very small, about 10 ^-3 to 10 ^-4 ° C ^-1 , and the conventional tri-O- (β-methoxyethoxy) ethyl cellulose, poly Ω-methacryloyloxytecanoate), and copolymers of γ-benzyl L-glutamate and dodecyl L-glutamate. The increase rate of? _M due to the temperature rise of acetoxypropylcellulose having an esterification degree of 3 and butoxypropylcellulose having an esterification degree of 2.8 tends to become constant and not increase any more when the degree of polymerization is about 100 or more. The polymerization degree of HPCTOn is 100 or more (Table 1), and the degree of polymerization of HPCTOn, HPCTO1Am and HPCTO2Am

Considering the fact that the values are almost constant at about 1.5 and the rate of increase of d due to thermal expansion is very small, the increase rate of λ _m due to temperature increase of HPCAm, HPCTO2, HPCTO1Am and HPCTO2Am is different (see FIG. 10) And the difference in the rate of decrease of q caused by the interaction between the cellulose or chitosan chains present in the pseudomemic layer due to the change in the conformation of the molecules due to the interaction between the chains.

Fig. 13 is a graph showing the results of comparison between the HPCTO (MS = 7.8, DS = 2.52) according to the comparative example and the cholesteric (D, q, p / d) of the image data.

(A) HPCTO2, MS = 7.8 and DS = 2.52, and HPCTO1Am and HPCTO2Am show changes in d with increasing m + 2 at 75 ° C and 110 ° C, Respectively. In the case of HPCTOs, considering that the number of carbon atoms in the substituent group (hydroxypropyl group) introduced into chitosan increases as MS increases by 1, d represented by HPCTO at 110 ° C indicates that the number of carbon atoms in the substituent introduced into chitosan is 1 0.0 &gt; nm, &lt; / RTI &gt; On the other hand, the d of HPCTO1Am and HPCTO2Am at 75 DEG C increases by about 0.02 nm and about 0.06 nm, respectively, as the number of carbon atoms in the aliphatic substituent is increased by one. Considering the fact that the rate of increase of d due to thermal expansion is very small as mentioned above, increase of d due to an increase in the number of carbon atoms in the substituent represented by HPCTO and HPCTO1Am is almost the same in the NH period existing in HPCTO, The difference in the hydrogen bonding force between NH and C = O groups present in HPCTO1Am and the difference in the chemical structure of the substituents introduced into chitosan, that is, the branch structure of the hydroxypropyl group and the linearity of the aliphatic substituent It is thought that this is caused by the difference in the filling structure of the side chain groups caused by the difference in structure. On the other hand, the increase in d due to the increase of the number of carbon atoms in the aliphatic substituent represented by HPCTO2Am at the same temperature as HPCTO1Am is about three times larger than that of HPCTO1Am due to increase of MS of HPCTO due to decrease of packing density of side chain groups d is decreased.

, d 그리고 λ_m이 온도의 함수로서 주어진 경우, 콜레스테릭 물질이 나타내는 q와 p/d를 온도의 함수로서 구 할 수 있다. 시료들이 나타내는 q와 p/d의 온도의존성을 검토한 예로서 HPCTO2가 110℃에서 나타내는

, d 그리고 λ_m 값들 그리고 HPCTO(MS=7.8, DS=2.52)가 110℃에서 나타내는

=1.470, d=1.445 nm 그리고 λ_m=2387 nm 값들에 의해 평가되는 q 그리고 p/d 값들을 MS의 함수로서 각각 (b) 및 (c)에 나타냈다. 한편, HPCTO1Am과 HPCTO2Am이 75℃ 혹은 110℃에서 나타내는

, d 그리고 λ_m값들에 의해 평가되는 q 그리고 p/d 값들을 m+2의 함수로서 각각 (b) 그리고 (c)에 함께 나타냈다. HPCTO의 q는 MS가 증가함에 따라 감소하는 경향을 나타낸다. 이러한 현상과 유사하게 HPCTOnAm의 q는 m+2가 증가함에 따라 감소하는 경향을 나타낸다. 그러나 HPCTO들과 m+2가 동일한 HPCTOnAm이 나타내는 q는 HPCTO1Am(75℃)>HPCTO1Am(110℃)>HPCTO(110℃)≫HPCTO2Am(75℃)>HPCTO2Am(110℃)의 순으로 큰 경향을 나타낸다. 따라서, HPCTO들과 HPCTOnAm이 75℃혹은 110℃에서 1p를 구성하고 있는 유사네마틱 층들의 수가 현저한 차이를 나타내는 것은 주로 시료들의 q값의 차이 때문임을 알 수 있다. 에스터화도가 약 2.8인 HPCAm이 상온에서 나타내는 지방족 치환기의 탄소가 1개 증가에 의한 q의 평균 감소율은 약 0.27°로 보고되어 있다. 이러한 사실과는 판이하게 HPCTO1Am이 75℃와 110℃에서 나타내는 지방족 치환기의 탄소수 1개 증가에 의한 q의 평균 감소율은 각각 0.12° 그리고 0.08°인 반면 HPCTO2Am이 75℃ 그리고 110℃에서 나타내는 지방족 치환기의 탄소수 1개 증가에 의한 q의 평균감소율은 각각 약 0.009°그리고 0.008°로서 대단히 작은 경향을 나타낸다. 이러한 사실을 고려할 때, HPCTOnAm과 HPCAm이 동일한 온도에서 나타내는 λ_m의 차이는 주로 동일한 온도에서 나타내는 q 값들의 차이때문임을 알 수 있다.As described above, the amount of the substance forming the cholesteric phase

, d and λ _m are given as a function of temperature, we can obtain q and p / d, which are represented by cholesteric materials, as a function of temperature. As an example of examining the temperature dependence of q and p / d that the samples show, HPCTO2 shows

, d and λ _m values and HPCTO (MS = 7.8, DS = 2.52) at 110 ° C.

(B) and (c), respectively, as a function of the MS, which are evaluated by the values of d = 1.470, d = 1.445 nm and λ _m = 2387 nm. On the other hand, when HPCTO1Am and HPCTO2Am are represented at 75 DEG C or 110 DEG C

, q and p / d values evaluated by d and λ _m values are shown together in (b) and (c), respectively, as a function of m + 2. The q of HPCTO shows a tendency to decrease with increasing MS. Similar to this phenomenon, q of HPCTOnAm shows a tendency to decrease with increasing m + 2. However, q represented by HPCTOnAm in the same HPCTOnAm with HPCTOs shows a large tendency in the order of HPCTO1Am (75 ° C)> HPCTO1Am (110 ° C)> HPCTO (110 ° C), HPCTO2Am (75 ° C), and HPCTO2Am . Therefore, it can be seen that the difference in the number of the similar nematic layers constituting 1p at 75 ° C or 110 ° C by HPCTO and HPCTOnAm indicates a significant difference mainly due to the difference in q value of the samples. The average reduction rate of q due to an increase in the number of carbons of the aliphatic substituent group represented by HPCAm having an esterification degree of about 2.8 at room temperature is reported to be about 0.27 °. The average reduction rates of q due to the increase in the number of carbon atoms of the aliphatic substituents represented by HPCTO1Am at 75 ° C and 110 ° C are 0.12 ° and 0.08 °, respectively, while the HPCTO1Am shows the average number of carbon atoms of the aliphatic substituent represented by HPCTO2Am at 75 ° C and 110 ° C The average reduction rate of q by one increase is about 0.009 ° and 0.008 °, respectively, indicating a very small tendency. Considering this fact, it can be seen that the difference in λ _m that HPCTOnAm and HPCAm exhibit at the same temperature is mainly due to the difference in q values at the same temperature.

In conclusion, the difference in the rate of increase of λ _m on the cholesteric phase due to the temperature rise of HPCTO and HPCTOnAm is mainly due to the difference in the decrease of q caused by the difference in the length of the aliphatic substituent introduced in the temperature, MS of HPCTO and HPCTO As shown in Fig.

The contents of the present invention are summarized as follows.

The transition temperatures of glass and cholesteric to liquid phase of HPCTOs showed a tendency to decrease with increasing MS. On the other hand, when MS was the same, the transition temperatures of free and cholesteric to liquid phase of HPCTOA were lower than that of HPCTO, and the tendency was decreased as the length of aliphatic substituent introduced into HPCTO increased.

The HPCTO fatty acid esters of the present invention can be used to prepare cholesteric materials having an optical pitch in a wide wavelength range of about 400 to 1800 nm in a temperature range of about 160 DEG C at room temperature.

Like HPCTO, the optical pitch of HPCTOAs increased with increasing temperature. However, the rate of increase of the optical pitch due to the temperature increase indicated by HPCTOA was plate compared with that of HPCTO, and it decreased with increasing length of aliphatic substituent introduced into HPCTO. On the other hand, when the length of the aliphatic substituent introduced into HPCTO was the same, the increase rate of the optical pitch due to the temperature increase shown by HPCTOA showed a tendency to decrease as the MS of HPCTO increased. These facts indicate that the rate of reduction of the helical twisting power, which is governed by the chiral interaction between chitosan chains due to temperature elevation, decreases with increasing length of aliphatic substituents introduced into MS or HPCTO.

The transition temperature from the cholesteric phase to the liquid phase and the increase in the optical pitch due to temperature rise, which HPCTOAs show, differ markedly from the results reported for the fatty acid esters of HPC. This is due to the fact that the difference in MS and the change in the stereochemistry of HPCTOA due to the increase of temperature due to intramolecular or intermolecular hydrogen bonding between the secondary amino groups or carbonyl groups present in HPCTOA or the secondary amino groups and carbonyl groups are different from those of fatty acid esters of HPC .

Thus, the use of the HPCTO fatty acid esters according to the present invention makes it possible to control the temperature stability of the cholesteric phase, the temperature range of formation, and the temperature dependence of the optical pitch in a wide range, compared with the technology reported in HPCTO fatty acid esters and HPCTO Can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but variations and modifications may be effected within the spirit and scope of the invention. It is possible.

Claims (7)

N, O-hydroxypropyl chitosan having a degree of substitution (DS) in the range of 2.15 to 2.39 and a degree of molar substitution (MS) in the range of 2.9 to 4.1. The method according to claim 1,
Wherein the N, O-hydroxypropyl chitosan is a thermotropic cholesteric material having a right-handed helical structure in which the optical pitch is increased by a temperature rise. The OH group of the N, O-hydroxypropylchitosan or the NH group of the N, O-hydroxypropylchitosan having a degree of substitution (DS) in the range of 2.15 to 2.39 and a molar degree of substitution (MS) in the range of 2.9 to 4.1 is - (CO CH ₂ ) _m CH ₃ group (wherein m is 0 to 9). The method of claim 3,
Wherein the N, O-hydroxypropyl chitosan fatty acid ester is a thermotropic cholesteric material having a right-handed helical structure in which the optical pitch is increased by a temperature rise. The method of claim 3,
The N, O-hydroxypropyl chitosan fatty acid ester is an N, O-hydroxypropyl chitosan fatty acid ester having an esterification degree of 3. Synthesizing N, O-hydroxypropylchitosan; And
Hydroxypropyl chitosan fatty acid ester by reacting the synthesized N, O-hydroxypropyl chitosan with alkanoic acid chloride (ClOC (CH ₂ ) _m CH _{3, where} m is 0 to 9) Hydroxypropyl chitosan fatty acid ester. The method according to claim 6,
Wherein the step of synthesizing the N, O-hydroxypropyl chitosan comprises reacting chitosan with propylene oxide.

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