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FIELD OF THE INVENTION
The present invention is related to chiral smectic liquid crystalline
polymers, in particular to side-chain chiral smectic liquid crystalline
polymers.
BACKGROUND OF THE INVENTION
Recently, the synthesis of liquid crystalline polymers has attracted an
increasing interest among various macromolecular compounds, because of
their versatile applications, such as liquid crystal display (LCD)
devices, optical filtering lens, reflection lens, linear optical
polarizing lens (Displ. Technol., 1, 81 (1985)), and stationary phase
materials used in high performance chromatography (J. Org. Chem., 49, 4947
(1984)). In addition, researchers have focused on their use as an optical
memory material in the fabrication of erasable optical discs, for examples
articles published in Mol. Cryst. Liq. Letters., 102, 78 (1984); Mol
Cryst. Liq. Cryst., 102, 78(1984).
The potential applications of ferroelectric liquid crystals in
fast-switching, high resolution electrooptical devices is well documented.
[Clark, N. A. and Lagerwall, S. T. appl. Phys. Lett. 1980, 36,899;
Lagerwall, S. T. and Dahl, I. Mol. Crys. Liq. Crys. 1984, 114, 151;
Lagerwall, S. T., et al. Mol. Cryst. 1987, 152,503]
A number of ferroelectric liquid crystalline side-chain polymers have been
prepared during the past few years. Among them there are liquid
crystalline polymers having a backbone based on acrylates or acrylate
derivatives [V. P. Shibaev, et al. Polymer Bulletin, 12, 299 (1984); J. C.
Dubois, et al. Mol. Cryst. Liq. Cryst., 1986, Vol. 137, pp. 349-364; S.
Esselin, et al. Mol. Cryst. Liq. Cryst., 1988, Vol. 155, pp. 371-387; S.
Bualek, et al. Mol. Cryst. Liq Cryst., 1988, Vol. 155, pp. 47-56; S.
Uchida, et al. Mol. Cryst. Liq. Cryst., 1988, Vol. 155, pp. 93-102; K.
Shiraishi et al., Makromol. Chem., 190, 2235-2243 (1989); V. Percec, et
al. Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 27,
2367-2384 (1989); S. Esselin, et al. Liquid Crystal, 1987, Vol. 2, No. 4,
505-518; B. Messner, et al. Makromol. Chem. 192, 2383-2390 (1991); E. C.
Bolton, et al. Liquid Crystal, 1992, Vol. 12, No. 2,305-318; J. Bomelburg,
et al. Makromol. Chem., Rapid Commun. 12, 483-488 (1991); G. Scherowsky,
et al. Liquid Crystal, 1991, Vol. 10, No. 6, 809-819], liquid crystalline
polymers having a backbone of polylaurates [J. M. Guglieminetti, et al.
Polymer Bulletin 16, 411-418 (1986)], liquid crystalline polymers having a
backbone based on diazo-compounds or derivatives thereof [R. Zentel, et
al. Liq. Cryst., 1987, 2(1), 83-89; S. Bualek, et al. Makromol. Chem.,
189, 797-804(1988); H. Kapitza, et al. Makromol. Chem., 189, 1793-1807
(1988); R. Zentel Makromol. Chem., 190, 2869-2884 (1989); H. Kapitza, et
al. Makromol. Chem., 192, 1859-1872 ( 1991 ); S. U. Vallerien, et al.
Makromol. Chem., Rapid Commun., 10, 333-338 (1989)], liquid crystalline
polymers having a backbone of polytartrates [S. Ujiie, et al. Polymer.
Journal, Vol. 23, No. 12, pp. 1483-1488 (1991 )], and liquid crystalline
polymers having a backbone of polysuccinates [K. Fujishiro, et al. Liquid
Crystals, 1992, Vol. 12, No. 4, 561-573]. The above-mentioned liquid
crystalline polymers do not have a segment of polysiloxane in the
backbones thereof.
B. Hahn, et al. in their articles, Mol. Cryst. Liq. Cryst. Inc. Nonlin.
Opt., 1988, Vol. 157, pp. 125-150; and Macromolecules, Vol. 20, No. 12,
1987, disclose liquid crystalline polymers having a backbone of
polysiloxane. The mesogenic groups of these liquid crystalline
polysiloxanes contain 1,3-dioxanyl. C. Destrade, et al. in their article,
Liquid Crystals, 1991, Vol. 10, No. 4, pp. 457-493, disclose liquid
crystalline polysiloxanes containing .alpha.-chloroalkyl carboxylic acid
or aromatic ester of alkyl carboxylic acid mesogenic groups. The present
invention is directed to liquid crystalline polysiloxanes containing
mesogenic groups of alkyl ester or chloroalkyl ester of aromatic
carboxylic acid.
An object of the present invention is to provide novel liquid crystalline
polymers.
Another object of the present invention is to provide liquid crystalline
polysiloxanes.
Still another object of the present invention is to provide mesogenic
monomers for graft polymerizing onto a polysiloxane backbone.
SUMMARY OF THE INVENTION
A liquid crystalline polysiloxane having the following formula (I) is
disclosed:
##STR2##
wherein Me is methyl;
m represents the degree of polymerization of polymer backbone and is an
integer of about 40-80;
n represents the spacer between the backbone and the side-chain mesogenic
groups and is an integer of about 1-12;
Ar is phenylene, biphenylene, or naphthalene;
Ar' is phenylene or naphthalene;
X is halogen or methyl; and
R is C.sub.1 -C.sub.4 alkyl, such as methyl, ethyl, n-propyl, isopropyl,
n-butyl, 1-methylpropyl and 2-methylpropyl.
Preferably, Ar is para-phenylene; 4-,4'-para-biphenylene; or
2-,6-naphthalene.
Preferably, Ar' is para-phenylene or 2-,6-naphthalene.
Preferably, X is chlorine or methyl.
BRIEF DESCRIPTION OF THE DRAWINGS
The file of this patent contains at least one drawing executed in color.
Copies of this patent with color drawings will be provided by the Patent
and Trademark Office upon request and payment of the necessary fee.
FIG. 1 is a plot which show phase transition behavior of monomers I-10 to
I-12 as a function of the length of spacer, wherein .circle-solid.
represents the melting point, Tm; .box-solid. represents the isotropic
phase temperature, Ti; .tangle-solidup. represents the crystallization
temperature, Tc; and .quadrature. represent the cholesteric phase
temperature, N*.
FIG. 2 is a plot which show phase transition behavior of monomers I-13 to
I-15 as a function of the length of spacer, wherein .circle-solid.
represents the melting point, Tm; .box-solid. represents the isotropic
phase temperature, Ti; .tangle-solidup. represents the crystallization
temperature, Tc; and .quadrature. represent the cholesteric phase
temperature, N*.
FIG. 3 are normalized Differential Scanning Calorimeter (DSC) thermograms
(10.degree. C./min) for polymers P-2 to P-3: A) heating scan; B) cooling
scan.
FIG. 4 are normalized Differential Scanning Calorimeter (DSC) thermograms
(10.degree. C./min) for polymers P-5 to P-6: A) heating scan; B) cooling
scan.
FIG. 5 is a plot which show phase transition behavior of polymers P-1 to
P-3 as a function of the length of spacer, wherein .circle-solid.
represents the isotropic phase temperature; and .tangle-solidup.
represents the glass transition temperature.
FIG. 6 are Differential Scanning Calorimeter (DSC) thermograms (10.degree.
C./min) for monomer I-24.
FIG. 7 are Differential Scanning Calorimeter (DSC) thermograms (10.degree.
C./min) for polymer P-9.
FIG. 8 are Differential Scanning Calorimeter (DSC) thermograms (10.degree.
C./min) for monomer I-30.
FIG. 9 are Differential Scanning Calorimeter (DSC) thermograms (10.degree.
C./min) for polymer P-12.
FIG. 10 is a plot which shows mesomorphic ranges of monomers I-22 to I-24
and monomers I-28 to I-30: N*: chiral nematic phase; S.sub.A : smectic A
phase; and Sc*: chiral smectic C phase.
FIG. 11 is a plot which shows mesomorphic ranges of polymers P-7 to P-12:
S: smectic phase; K: crystalline phase; S.sub.1 : smectic A phase; and
S.sub.2 : chiral smectic C phase.
FIG. 12 is an optical polarizing micrograph (magnification 640X) of monomer
I-10: smectic A texture obtained at 46.8.degree. C.
FIG. 13 is an optical polarizing micrograph (magnification 640X) of monomer
I-11: smectic A texture obtained at 62.8.degree. C.
FIG. 14 is an optical polarizing micrograph (magnification 640X) of monomer
I-11: smectic A texture obtained at 64.7%.
FIG. 15 is an optical polarizing micrograph of polymer P-3: smectic texture
obtained at 157.5%.
FIG. 16 is an optical polarizing micrograph of monomer I-13: cholesteric
texture obtained at 76.7.degree. C.
FIG. 17 is an optical polarizing micrograph of monomer I-13: smectic A
texture obtained at 67.3%.
FIG. 18 is an optical polarizing micrograph of polymer P-5: smectic A
texture obtained at 25%.
FIG. 19 is an optical polarizing micrograph of polymer P-6: smectic A
texture obtained at 25%.
FIG. 20(A), (B) are optical polarizing micrographs of monomer I-22: (A)
cholesteric texture obtained at 83.degree. C.; (B) smectic A texture
obtained at 66.3%.
FIGS. 21(A) and (B) are the optical polarizing micrographs of monomer I-23:
(A) the cholesteric texture obtained at 87.degree. C. on cooling; (B) the
smectic A texture obtained at 78.4.degree. C. on cooling.
FIGS. 22(A) and (B) are the optical polarizing micrographs of monomer I-24:
(A) the focal-conic fan smectic A texture obtained at 92.degree. C. on
cooling; (B) the broken fan texture of chiral smectic C phase obtained at
40.degree. C. on cooling.
FIGS. 23 (A) and (B) are the optical polarizing micrographs of polymer P-9:
(A) fan-like texture of smectic A phase obtained at 98.degree. C. on
cooling; (B) broken fan texture obtained at 30.degree. C.
FIGS. 24 (A) and (B) are the optical polarizing micrographs of monomer
I-28: (A) cholesteric texture obtained at 203.degree. C. on cooling; (B)
chiral smectic C texture obtained at 145.degree. C. on cooling.
FIGS. 25 (A) and (B) are the optical polarizing micrographs of monomer
I-29: (A) smectic A texture obtained at 170.degree. C. on cooling; (B)
chiral smectic C texture obtained at 148.degree. C. on cooling.
FIGS. 26 (A) and (B) are the optical polarizing micrographs of monomer
I-30: (A) smectic. A texture obtained at 181.degree. C. on cooling; (B)
chiral smectic C texture obtained at 124.degree. C. on cooling.
FIGS. 27 (A) and (B) are the optical polarizing micrographs of polymer
P-12: (A) smectic A texture obtained at 275.degree. C. on cooling; (B)
chiral smectic C texture obtained at 122.degree. C. on cooling.
DETAILED DESCRIPTION OF THE INVENTION
A suitable method of synthesizing the liquid crystalline polymer of the
above formula (I) comprises graft polymerizing the following monomer (II):
##STR3##
wherein n, Ar, Ar', X and R: are defined same as in the formula (I), onto
a polymer backbone having the following formula (III) in a suitable
solvent and under suitable reacting conditions:
##STR4##
wherein Me and m are defined same as in the formula (I).
Said suitable solvent includes any organic solvent which renders the
compounds of the above formulas (I), (II) and (III) soluble or dispersible
therein, and does not reacted with the compounds of the above formulas
(I), (II) or (III), such as aromatic solvent: benzene, toluene,
dimethylbenzene, and the like. The organic solvent is preferably
dehydrated to an anhydrous form before use.
Said suitable reacting conditions mainly includes a suitable catalyst and a
suitable reacting temperature under which the graft polymerization of the
compounds (II) and (III) can be carried out. Said suitable catalyst can be
any catalyst which catalyzes the graft polymerization of
polymethylhydrosiloxane and monomer having vinyl group, such as
platinum-divinyltetramethyldisiloxane complex. Said suitable reacting
temperature means a temperature which is not higher than the boiling point
of said suitable solvent, preferably ranging from about 60.degree. C. to
about 150.degree. C., and most preferably ranging from 80.degree. C. to
110.degree. C. A refluxing apparatus is preferably adopted when the graft
polymerization undergoes at the boiling temperature of said organic
solvent.
The polymer backbone of formula (III) can be prepared by any known methods
disclosed in the art or purchased directly from the market, namely
Petrarch Systems Inc., Bristal, Pa., U.S.A.
The mesogenic monomers of formula (II) can be synthesized according to, but
not limited to, the methods disclosed in the following Preparation
Examples.
In the following examples, the organic solvents used are preferably in
anhydrous form. Anhydrous ethyl ether was prepared by drying over sodium
particles and distilling under nitrogen with refluxing, wherein dibenzyl
ketone was used as an indicator. Toluene, benzene and ethanol were dried
over sodium metal. Anhydrous dichloromethane was prepared by drying over
calcium chloride, refluxing under nitrogen for several hours, and then
distillation. The organic solvents were dehydrated immediately before use
or the dehydrated organic solvents were sealed in containers which were
then stored in a drier.
The following apparatuses were used in the analysis and identification of
the characteristics of the intermediates and liquid crystalline
polysiloxanes synthesized in the following examples:
1. FT-IR spectrum: Nicolet: 520 FT-IR spectrometer was used; a liquid
specimen was contained between two KBr tablets and measured; and the unit
is cm.sup.-1.
2. NMR spectrum: Bruker AM 400 MHz NMR was used. d-Chloroform was used as
solvent; the chemical shift unit is ppm; the unit of coupling constant is
Hz; and .delta.=0.00 ppm of tetramethylsilane was used as an internal
standard. s represents singlet; d represents doublet; t represents
triplet; q represents quarlet; and m represent multiplet.
3. Differential Scanning Calorimeter (DSC): Dupont, type 910 DSC equipped
with a mechanical cooling accessory and type 2100 Computer/Thermal
Analyzer were used. The temperature calibration was carried out by using
5-10 mg in both heating and cooling curves. The heating and cooling rates
were 10.degree. C./min. The phase transition temperatures and the
thermodynamic function values (.DELTA.H and .DELTA.S)of the specimens were
collected by taking the maximum or minimum values. The glass transition
temperatures (Tg's) of polymer specimens were taken at the point of
maximum inflection.
4. Optical Polarizing Microscope: Nikon, Microphot-FX optical microscope
(40X-800X) was used. Heating and cooling rates were controlled at
10.degree. C./min by using a Mettler FP82 hot stage and a FP 80 central
processor.
5. Digital Polarimeter: JASCO MODEL DIP-140 polarimeter equipped with a
sodium lamp was used. The length of the specimen groove is 100 cm; 1%
dextrose having [.alpha.].sub.D =+52.5.about.+53 was used as a calibration
standard; and all the specimens were tested at room temperature.
6. Medium Pressure Liquid Chromatography: BUCHI 681 Chromatography pump,
Merck Lichro-prop Si 60 310 mm.times.25 mm (40-63 .mu.m) Chromatography
column and BUCHI 3684 fraction collector were used. This apparatus was
used when a purification of a monomer specimen by column chromatography
was required.
7. Rotary Vacuum Evaporator: EYELA, type N-1 reduced pressure concentrator
was used.
The present invention will be further understood from the following
Preparation Examples 0-30 and Examples 1-12, which are used to illustrate
and not to limit the scope of the present invention.
PREPARATION EXAMPLE 0
Synthesis of 10-Undecen-1-yl tosylate (I-0)
Nitrogen was introduced into a three necks flask containing 50 ml anhydrous
pyridine which was stirred at 10.degree. C. 17 g (0.1 mole)
10-undecen-1-ol was added to the stirred pyridine, and then p-tolysufonyl
chloride was added slowly such that the temperature of the stirred mixture
was not high than 20.degree. C. The stirring was maintained for 10 hours
at room temperature, 250 ml ice water was added to the stirred mixture and
then extracted with ethyl ether. The ethyl ether layer was collected,
washed with 50% HCl aqueous solution, dried over anhydrous MgSO.sub.4,
filtered and then concentrated to yield 26.81 g colorless liquid. Yield:
79.6%.
.sup.1 H-NMR (CDCl.sub.3, .delta.): I-0 1.11-1.65(m,14H, --(CH.sub.2).sub.7
--, 2.04-2.10 (q,2H,--CH.sub.2 --CH.dbd.),2.49(s,3H, -ph--CH.sub.3),
4.05-4.10 (t,2H, --O--CH.sub.2 --CH.sub.2 --),
4.93-5.05(m,2H,--CH.dbd.CH.sub.2), 5.78-5.88(m,1H, --CH.dbd.CH.sub.2),
7.49-7.36(q,4H,ArH)
PREPARATION EXAMPLES 1-2
Synthesis of:
(2S)-2-chloro-4-methyl pentanoic acid (I-1);
(2S,3S)-2-chloro-3-methyl pentanoic acid (I-2).
78.7 g (0.6 mole) 2-amino-4-methyl pentanoic acid (preparation example 1)
or 0.6 mole 2-amino-3-methyl pentanoic acid (preparation example 2) was
dissolved in 700 ml 6N HCl. Total 91 g (1.3 mole) sodium nitrite powder
was divided into several portions and were added To the solution in a span
of 2 hours while an ice bath was used. The reaction was carried out for
5-6 hours at 0.degree.-5.degree. C., the reaction mixture was extracted
with ethyl ether for three times, washed with saturated NaCl aqueous
solution, dried over MgSO.sub.4, concentrated, and distilled under reduced
pressure twice to yield a transparent liquid product. Yield: I-1: 74.7%;
I-2: 69.5%. mp: I-1:92.degree. C./3 mmHg; I-2:88.degree. C./3 mmHg. The
optical rotation [.alpha.].sup.25.sub.D (chloroform): I-1:-I3.98 (neat
liquid); I-2: -4.78 (neat liquid).
.sup.1 H-NMR (CDCl.sub.3, .delta.) I-1 0.85-1.2 (q, 6H,
--CH.sub.3),1.75-1.90(m,3H,--CH--, --CH.sub.2 --), 4.28-4.38 (t,1H,
--CH--COO), 8.8 (b,1H,COOH) I-2
0.86-1.04(m,6H,--CH.sub.3),1.75-1.90(m,3H,--CH--CH.sub.2 --),
4.32-4.41(d,1H,--CH--COOH), 10.32(b,1H,COOH)
PREPARATION EXAMPLES 3-4
Synthesis of
(2S)-2-chloro-4-methyl pentanol (I-3);
(2S,3S)-2-chloro-3-methyl pentanol (I-4)
To a solution of 9.05 g (238.5 mmole) LiAlH.sub.4 in 250 ml anhydrous ethyl
ether 36.42 g (238.5 mmole) compound I-1 (preparation example 3) or 238.5
mmole compound I-2 (preparation example 4) was added dropwise while an ice
bath was used. The ice bath was removed when the addition was completed,
and the reaction was carried out at room temperature for five hours, an
excess amount of ethyl acetate was added to the reaction mixture to react
with the residual LiAlH.sub.4, and then 60 ml 10% HCl aqueous solution was
introduced until no bubbles was generated in the mixture. The resulting
reaction mixture was filtered, extracted, dried over MgSO.sub.4,
concentrated and distilled under reduced pressure to yield a transparent
liquid product. Yield: I-3: 46%; I-4: 40%. mp: I-3:48.degree. C./3 mmHg;
I-4: 36.degree. C./1 mmHg. The optical rotation [.alpha.].sup.25.sub.D
(chloroform): I-3: +3.16 (neat liquid); I-4: -7.6 (neat liquid).
.sup.1 H-NMR(CDCl.sub.3,.delta.) I-3
0.88-0.98(q,6H,--CH.sub.3),1.45-1.75(AB-m,2H,--CH--CH.sub.2 --),
2.13(s,1H,HO--), 3.61-3.84(AB-m,2H,--O--CH.sub.2 --),
4.07-4.14(m,1H,Cl--CH--) I-4 0.9-1.0(t,3H,--CH.sub.2 --CH.sub.3),
1.1(d,3H,--CH--CH.sub.3), 1.3-1.7(AB-m,2H,CH.sub.3 --CH--CH.sub.2 --),
1.9-2.0(m,1H,--CH--), 3.6-3.8 (AB-m, 2H, O--CH.sub.2 --), 4.07-4.14
(m,1H,Cl--CH--)
PREPARATION EXAMPLES 5-6
Synthesis of
(2S)-2-chloro-4-methylpentyl 4-hydroxybenzoate (I-5);
(2S,3S)-2-chloro-3-methylpentyl 4-hydroxybenzoate (I-6)
In a 30 ml flask equipped with a Dean-Stark trap 20 ml anhydrous benzene,
9.66 (70 mmole) 4-hydroxybenzoic acid, 20.5 g (150 mmole) compound 3
(preparation example 5) or 150 mmole compound 4 (preparation example 6)
and 4 drops of sulfuric acid were charged in sequence and refluxed until 1
ml water was collected in the Dean-Stark trap. The esterification reaction
mixture was cooled to room temperature, filtered, extracted with 150 ml
ethyl ether. The ethyl ether layer was collected, washed with 10 ml 2%
(w/w) sodium hydrogen carbonate aqueous solution twice, washed with
saturated NaCl aqueous solution, dried over MgSO.sub.4, concentrated,
distilled to remove the residual compound I-3 or I-4, and purified with
silica gel 70-230 mesh column chromatography (500 ml of ethyl
acetate/n-hexane =1/4 mixture was used as eluent) to obtain product.
Yield: I-5: 86%; I-6:-90%. The optical rotation [.alpha.].sup.25.sub.D
(chloroform): I-5: -3.12 (c=1.6); I-6: +2.03 (c=2.7).
.sup.1 H-NMR (CDCl.sub.3, .delta.) I-5 0.9-1.0(q,6H,-CH.sub.3),
1.56-1.90(AB-m,2H,--CH.sub.2 --CO), 4.38-4.51(AB-q,2H,COO--CH.sub.2 --),
6.65(s,1H,ArOH), 6.9-8.0 (AB-d, 4H, ArH) I-6 0.9-1.0 (t,3H,--CH.sub.2
--CH.sub.3) , 1.1 (d,3H,--CH--CH.sub.3), 1.3-1.7(AB,m,2H,CH.sub.3
--CH--CH.sub.2 --), 1.9-2.0(m,1H,CH.sub.3 --CH--), 4.2(m,1H,Cl--CH--),
4.45-4.64(q,2H,COO--CH.sub.2 --), 6.8 (s,1H,ArOH), 6.9-8.0 (AB-d,4H, ArH)
PREPARATION EXAMPLES 7-9
Synthesis of
6-Allyloxy naphthyl-2-carboxylic acid (I-7);
6-(5-Hexene-1-yloxy)naphthyl-2-carboxylic acid (I-8);
6-(10-Undecen-1-yloxy)naphthyl-2-carboxylic acid (I-9).
Compounds I-7 to I-9 were synthesized by the same method. The synthesis of
compound I-7 was described below as an example. 1.5 g (8 mmole)
6-hydroxyl-2-benzoic acid and 500 ml ethanol were charged to a flask, 50
ml water and 1.07 g (19 mmole) KOH were then added and the mixture was
refluxed for one hour. 3.89 g compound I-0 was introduced into the flask
dropwise, the mixture was refluxed for two hours, cooled to room
temperature and diluted with water and dilute HCl aqueous solution. White
precipitate was obtained by filtration and then recrystallized from an
acetic acid aqueous solution to yield 2.32 g of white solid. Yield: I-7:
89%; I-8: 81%; I-9: 85.5%. mp: I-7: 150.degree. C.; I-8: 125.degree. C.;
I-9: 118.degree. C.
.sup.1 H-NMR (CDCl.sub.3, .delta.) I-7 4.6(d,2H,.dbd.CH--CH.sub.2
--O),5.32-5.53(m,2H,CH.sub.2 .dbd.),
6.09-6.20(m,1H,.dbd.CH--),7.2-8.7(m,6H,ArH) I-8 1.56-1.70(m,2H,--CH.sub.2
--),1.86-2.00(m,2H,--CH.sub.2 --), 2.14-2.28(m,2H,.dbd.CH--CH.sub.2
--),4.08-4.20(t,2H, --CH.sub.2 --O),4.98-5.13(mq,2H,.dbd.CH.sub.2),
5.80-5.95 (m, 1H,.dbd.CH--),7.10-8.65(m,6H,ArH) I-9
1.25-1.60(m,12H,--(CH.sub.2).sub.6 --),1.72-1.92 (m,2H, --CH.sub.2
--CH.sub.2 --O),2.0-2.1(q,2H,.dbd.CH--CH.sub.2 --CH.sub.2),
4.12(t,--CH.sub.2
--O),4.91-5.15(m,4H,.dbd.CH.sub.2),5.76-5.90(m,1H,.dbd.CH--),
7.16-8.63(m,6H,ArH)
PREPARATION EXAMPLES 10-15
Synthesis of
(2S)-[4-(2-Chloro-4-methylpentoxycarbonyl)phenyl]6-allyloxy-2-naphthoate
(I-10);
(2S)-[4-(2-Chloro-4-methylpentoxycarbonyl)phenyl]6-(5-hexen-1-yloxy)-2-naph
thoate (I-11);
(2S)-[4-(2-Chloro-4-methylpentoxycarbonyl)phenyl]6-(10-undecen-1-yloxy)-2-n
aphthoate (I-12);
(2S,3S)-[4-(2-Chloro-3-methylpentoxycarbonyl)phenyl]6-allyloxy-2naphthoate
(I-13);
(2S,3S)-[4-(2-Chloro-3-methylpentoxycarbonyl)phenyl]6-(5-hexen-1-yloxy)-2-n
aphthoate (I-14);
(2S,3S)-[4-(2-Chloro-3-methylpentoxycarbonyl)
phenyl]6-(10-undecen-1-yloxy)-2-naphythoate (I-15).
Compounds I-10 to I-15 were synthesized by the same method which comprises
converting an carboxylic acid group of compound I-7 (preparation examples
10 and 13), I-8 (preparation examples 11 and t4) or I-9 (preparation
examples 12 and 15) to acyl chloride group and reacting with the hydroxyl
group of compound I-3 (preparation examples 10-12)or I-4 (preparation
examples 13-15). The synthesis of compound I-10 was described below as an
example. Part (A): 0.6 g (2.36 mmole) compound I-7, 20 ml dichloromethane,
one drop of dimethylformamide and 2 ml thionylchloride were mixed and
refluxed. The solvent and excess thionylchloride were removed under
reduced pressure to give the corresponding acyl chloride which was then
dissolved in 10 ml anhydrous dichloromethane and added to part (B). Part
(B): 0.67 g (2.63 mmole) compound I-3, 0.43 ml triethylamine and 20 ml
anhydrous dichloromethane were mixed and stirred in an ice water bath for
10 minutes. Part (A) solution was poured into part (B), stirred at room
temperature for two hours, and extracted with 20 dichloromethane. The
organic layer was collected, washed with saturated NaCl aqueous solution,
dried over MgSO.sub.4, concentrated, purified with a medium pressure
liquid chromatography (a mixture; of ethyl acetate/n-hexane=1/25 was used
as eluent), and concentrated to obtain a white solid product. Yield: I-10:
75.3%; I-11: 67%; I-12: 78,6%; I-13: 59.7%; I-14: 74.5%; I-15: 76%. The
optical rotation [.alpha.].sup.25.sub.D (chloroform): I-10: -5.96
(c=6.52); I-11: -10.02 (c=1.6); I-12: -5.66 (c=1.1); I-13: +10.72 (c=4);
I-14:I-15: +9.71 (c=0.7).
.sup.1 H-NMR (CDCl.sub.3, .delta.) I-10
0.9-1.1(q,6H,--CH.sub.3),1.5-1.8(AB-m,2H,--CHCl--CH.sub.2 --),
1.9-2.1(m,1H,CH.sub.2 --CH--),4.2-4.3(m,1H,--CHCl--),
4.4-4.6(AB-q,2H,O--CH.sub.2 --CClH--), 4.7 (d,2H;=CH--CH.sub.2
.dbd.O),5.3-5.6(m,2H,CH.sub.2 .dbd.),6.1-6.2(m,1H,.dbd.CH--), 7.2-7.8
(m,10H,ArH) I-11 0.9-1.1(q,6H,--CH.sub.3),1.58-1.80(m,4H,--CH.sub.2
--,--CClH --CH.sub.2 --),1.82-2.01(m,3H,.dbd.CH--CH.sub.2
--,--CH--),2.02-2.22(m,2H,--CH.sub.2 --CH.sub.2 --O--),
4.08-4.15(t,2H,--CH.sub.2 --CH.sub.2 --O),4.2-4.3(m,1H,--CHCl--)
4.4-4.52(AB-q,2H, O--CH.sub.2 --CHCl--), 4.95-5.09(m,2H,CH.sub.2
.dbd.CH--),5.78-5.90(m,1H,CH.sub.2 .dbd.CH--), 7.14-8.68(m,10H,ArH) I-12
0.9-1.1(q,6H,--CH.sub.3), 1.25-1.55(m,12H,--(CH.sub.2).sub.6 --), 1.6-1.8
(Ag-m,2H, CHCl--CH.sub.2 --), 1.85-1.95 (m, 2H,--CH.sub.2 --CH.sub.2
O),1.95-2.02(m,1H,--CH--), 2.03-2.10 (q,2H,.dbd.CH--CH.sub.2 --),
4.1-4.15(t,2H,CH--CH.sub.2 --O), 4.23-4.32(m,1H,--CHCl--),
4.42-4.56(AB-m,2H,.dbd.O--CH.sub.2 --CHCl--), I-13 0.9-1.0
(t,3H,--CH.sub.2 --CH.sub.3),1.05-1.15(d,2H,--CH--CH.sub.3),
1.32-1.72(m,2H,--CH--CH.sub.2 --),1.87-2.05(m,1H,
--CH--),4.15-4.25(m,1H,--CHCl--),4.45-4.65(AB-q,2H, --COO--CH.sub.2
--),4.7(d,2H,.dbd.CH--CH.sub.2 --O),5.32-5.54(m, 2H,CH.sub.2 .dbd.),
6.08-6.21(m,1H,CH.sub.1 .dbd.CH--), 7.18-8.61 m,10H,ArH) I-14
0.9-1.0(t,3H,--CH.sub.2 --CH.sub.3),1.05-1.1(d,3H,--CH--CH.sub.3),
1.32-1.68 (m,4H,--CH--CH.sub.2 --CH.sub.2 --,--CH--CH--CH.sub.2),
1.34-1.56(m,3H,--CH.sub.2 --CH.sub.2 --O--,--CH--), 2.11-2.20
(q,2H,.dbd.CH--CH.sub.2 --), 4.08-4.12(t,2H,--CH.sub.2 --O), 4.14-4.21
(m,1H,--CHCl--),4.44-4.62(AB-q,2H,COO--CH.sub.2 --),
4.96-5.09(m,2H,CH.sub.2 .dbd.),5.8-5.9(m,1H,.dbd.CH--),7.15-8.69
(m,10H,ArH)
I-15 0.9-1.0(t,3m,--CH.sub.2 --CH.sub.3),1.05-1.15(d,3H,--CH--CH.sub.3),
1.24-1.71(m,14H,--CH--CH.sub.2 --CH.sub.3,--(CH.sub.2).sub.6),
1.83-2.0(m,3H,--CH.sub.2 --CH.sub.2
--O,--CH--),2.02-2.1(q,2H,.dbd.CH--CH.sub.2 --),4.09-4.15(t,2H,--CH.sub.2
--O),4.18-4.23(m,1H, CHCl--).4.46-4.64(q,2H,COO--CH.sub.2 --),4.92-5.06(q,
2H,CH.sub.2 .dbd.),5.77-5.90(m,1H,.dbd.CH--),7.20-8.72(m, 10H,ArH)
Examples 1-6
Synthesis of
Poly[methyl[(2S)-[4-(2-chloro-4-methylpentoxy-carbonyl)phenyl]6-allyloxy-2-
naphthoate]siloxane](P-1);
Poly[methyl[(2S
)-[4(2-chloro-4-methylpentoxy-carbonyl)phenyl]6-(5-hexen-1-yloxy)-2-naphth
oate]siloxane](P-2);
Poly[methyl[(2S)-[4-(2-chloro-4-methylpentoxy-carbonyl)phenyl]6-(10-undecen
-1-yloxy)-2-naphthoate]siloxane](P-3);
Poly[methyl[(2S,3S)-[4-(2-chloro-3-methylpentoxy-carbonyl
)phenyl]6-allyloxy-2-naphthoate]siloxane](P-4);
Poly[methyl[(2S,3S)-[4-(2-chloro-3-methylpentoxy-carbonyl)phenyl]6-(5-hexen
-1-yloxy)-2-naphthoate]siloxane](P-5);
Poly[methyl[(2S,3S)-[4-(2-chloro-3-methylpentoxy-carbonyl)phenyl]6-(10-unde
cen-1-yloxy)-2-naphthoate]siloxane](P-6)
Polymethylhydrogensiloxane (Code PS120) having a number average molecular
weight of 2270 and platinum-divinyltetramethyldisiloxane complex catalyst
were obtained from Petrarch Systems Inc., Bristal, Pa., U.S.A. and used as
received. 1.1 equivalent moles of compound I-10 (example 1), I-11 (example
2), I-12 (example 3), I-13 (example 4), I-14 (example 5) or I-15 (example
6) was dissolved in an suitable amount of toluene together with
polymethylhydrogensiloxane. The reaction was carried cut at about
80.degree. C. in the presence of platinum divinyltetramethyldisiloxane
complex catalyst. FT-IR analysis was run to detect the absorption peak of
Si-H bond (2180 cm.sup.-1) of the reaction mixture. The hydrosilation
reaction was complete when the Si-H absorption peak disappeared. The
reaction mixture was concentrated and the reaction product was purified by
several reprecipitations from methanol.
Table 1 shows the m and n values of the synthesized polymers P-1 to P-6 in
the above formula (I).
TABLE 1
______________________________________
Example Monomer Polymer m n
______________________________________
1 I-10 P-1 40 1
2 I-11 P-2 40 4
3 I-12 P-3 40 9
4 I-13 P-4 40 1
5 I-14 P-5 40 4
6 I-15 P-6 40 9
______________________________________
The monomers I-10 to I-15 and polymers P-1 to P-6 were characterized by
differential scanning calorimetry and optical polarizing microscopy.
Tables 2 and 3 present the thermal transitions and thermodynamic parameters
of the synthesized monomers I-10 to I-12 and I-13 to I-15 respectively. It
can be seen from the DSC heating and cooling traces and .DELTA.H values
that monomers I-10 to I-12 and I-13 to I-15 have substantially the same
phase transitions. The optical polarizing micrographs of monomers I-10
(FIG. 12) and I-13 (FIGS. 16-17) display both the cholesteric texture and
smectic A texture. The optical polarizing micrographs of monomers I-11
(FIGS. 13-14), I-12, I-14 and I-15 display only the smectic A texture.
FIG. 1 shows that the phase transition behavior of monomers I-10 to I-12
as a function of the number (n) of carbon atom of the spacer. FIG. 2 shows
that the phase transition behavior of monomers I-13:to I-15 as a function
of the number (n) of carbon atom of the spacer. It can be seen from FIGS.
1 and 2 that the melting point of monomers I-10 to I-15 decreases as the
carbon atom number of the spacer thereof increases, and the temperature
range in which monomers I-10 to I-15 exhibit smectic A phase increases as
the carbon atom number of the, spacer thereof increase. This phenomenon is
more significant in FIG. 2 than in FIG. 1. Tables 4 and 5 present the
thermal transitions and thermodynamic parameters of the synthesized
polymers P-1 to P-3 and P-4 to P-6 respectively. The polymers P-1 to P-3
are different from the polymers P-4 to P-6 only in the substituent
position on the mesogenic group, and the DSC thermograms of P-2 and P-3
presented in FIGS. 3 and the DSC thermograms of P-5 and P-6 presented 5 in
FIG. 4 show that P-2 and P-3 have substantially the same phase transitions
as P-5 and P-6 respectively. The optical polarizing microscopy shows that
all the polymers P-1 to P-6 exhibit smectic A phase (FIGS. 15, 18-19).
FIG. 5 shows that the phase transition behavior of polymers P-1 to P-3 as
a function of the number (n) of carbon atom of the spacer. It can be seen
from FIG. 5 that the glass transition temperature decreases, isotropic
transition temperature increases and the temperature range in which the
polymer exhibits smectic A phase becomes wider, when the carbon atom
number of the spacer of polymers P-1 to P-3 increases. It can be also seen
from Table 4 that .DELTA.H value increases as the carbon atom number of
the spacer of polymers P-1 to P-3 increases. It is believed that these
phenomena are caused by a longer flexible spacer which in turn enhances a
more regular arrangement of the side chains.
TABLE 2
______________________________________
Phase transitions and phase transition enthalpies for
monomers I-10 to I-12
______________________________________
Phase transitions, .degree.C.(corresponding enthalpy
changes, Kcal/mol)
(A) Heating scan
Monomer n Tm(.DELTA.Hm)
T(.DELTA.H)
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