SU887574A1 - Liquid crystal polyacrylates and polymethacrylates containing cyanodiphenyl groups possessing activity towards orientation in electric field - Google Patents

Description

viscosity in tetrahydrofuran at 30 ° C from 0.06 to 0.3. In this case, absolute benzene is used as solvents. and tetrahydrofuran, and as initiators, gs (., o-azobisisobutyronitrile (DAK) and dicyclohexyl peroxydicarbonate (CPC).

Example 1. Poly-4-G1 ((methacryloyloxy) -UNedacyloxy-4-cyanodiphenyl. 1.5 g of (methacryloyl oxy) -undecyloxy-4-cyanodiphenyl and 0.0075 g of DAK are dissolved in 15 ml of absolute benzene. Polymerization is carried out in an argon atmosphere for 30 hours. The polymer is precipitated with methanol, re-precipitated from chloroform to methanol and dried in vacuum. Yield: 1.25 g (83.5%). Cl3 0.30 (tetrahydrofuran, 30 °).

Found,%: C 77.54; H 8, 11; N 3.33,

CggUjsNOg,

Calculated,%: C 77.60; H 8.03; N 3.24.

Example 2. Poly- | 4-Cu- (methacryloyloxy) -amyloxy and J-4-cyanodiphenyl are prepared in a similar manner; , with a yield of 80%. P 10.16 (THF, 30 C)

Found,%: C 76.08; H 6.72; N 4.19.

Sgna Oz

Calculated,%: 75.70; H 6.60; N 4.01.

Example 3. Analogously to example 1, poly-4- (3- (methacryloyloxy) -ethoxy3-4-cyanodiphenyl) is obtained with a yield of 64%. P o, 13 (THF, 30 ° C).

Found,% .j C 74.05; H 5.44; N 4.62.

C 9lt | 7NO.

Calculated,%: C, 74.30; H 5.54; N .4,65.

Example 4 Poly-4 (methacryloyloxy) -undecyl} -4-cyanodiphenyl 4. 1.0 g of (methacryloyloxy) -decyl} -4-cyanodiphenyl and 0.005 g of CPA are dissolved in 15 ml of absolute benzene. The polymerization is carried out in an argon atmosphere at 30 ° C for 20 hours. The polymer is precipitated with methanol, re-precipitated from chloroform to methanol twice and dried in vacuum. Yield: 0.66 g (66%). 0.16 (THF, 30 ° C).

Found,%: C 80.07, H 8.34, N 3.19.

C28% 5-N02.

calculated,%: C 80.58; H 8.39; N 3.36.

Example 5. Analogously to Example 4, poly-j4-p- (acryloyloxy) -ethoxy-4-dianodiphenyl} is obtained in a yield of 83%. P J 0.08 (THF, 30 O.

Found,%: C 73.55; And 5.52; N 4.90.

c eH / s-NOj

Calculated;%: C 73.80; H 5.13; N 4.78.

Example 6. Analogously to Example 4, poly-J4- «;-( acryloyloxy) -amyloxy-4-cyanodiphenyl} is obtained in 89% yield, G 130.06 (THF,).

Found,%: C 75.15; H 6.16; N 4.21.

.NO.

Calculated,%; C 75.30; H 6.28; N 4.18.

Example 7. As in Example 4, poly- 4 - {(V- (methacryloyl) -ylendekanoyl-3-4-cyano diphenyl j is obtained using tetrahydrofuran instead of benzene. Yield 83%, 14 (THF,).

Found,%: C 74.90; H 7.50; N 3.56. C20H35N04

Calculated,%: from 75.20; H 7.39; N 3.14.

Example 8. Copolymer of 4-GM- (methacryloyloxy) -enecyloxy-4-cyanodiphenyl and (acryloyloxy) -ethoxy-4-cyanodiphenyl. 0.300 g of (methacryloyloxy) -undecyloxy-4-cyanodiphenyl a and 0.204 g of (acryloyloxy) -ethoxy-4-cyanodiphenyl (molar ratio) are dissolved in 5 ml of tetrahydrofuran. 0.0025 g of DAK is added and the polymerization is carried out in an argon atmosphere at 60 ° C for 10 hours. The copolymer is precipitated

methanol and re-precipitate twice from chloroform to methanol. Yield 0.3 g (60%), I; K) 0.12 (THF, 30 ° C).

Example 9. Analogously to example 8, get the copolymer

- (methacryloyloxy) -amylox1 / -4-cyanodiphenyl and (acryloyloxy) -ethoxy-4-cyanodiphenyl in 62% yield. , 08 (THF, 30 ° C).

All polymers and copolymers do not crystallize, which is confirmed by

the presence of an amorphous halo on the x-ray diffraction patterns of these polymers, and at certain temperatures, it transforms into a highly elastic (glass transition temperature) and flowable (pour point) state (see table). Polarization-microscopic examination of polymer films shows that all samples, except for sample 3,

birefringent pattern in a glassy, highly elastoic and shaky state. The birefusion retreat disappears and reappears when cooled at a specific temperature for each polymer (clarification temperature) that is much higher than the pour point. The study of polymers by the method of differential scanning calorimetry shows that with

the clarification temperature occurs a first-order phase transition from the liquid-crystal state to an isotropic melt, which is characterized by the heat of transition dM (see

table).

The data in this table confirm the existence of a liquid crystal state in polymers containing cyaniphenyl groups.

For the polymer of Example 4, the dielectric constant anisotropy (D6.) Is evaluated. For this, the anisotropy of a mixture of this polymer with an H-106 nematic liquid crystal is measured at a frequency of 1000 Hz. The dB value for the pure polymer is calculated by the additive scheme and is equal to 14. The larger anisotropy of the dielectric constant, as well as the presence of the nematic structure of the polymers, makes it possible to orient such polymers in an electric field. When exposed to samples of polymers of an alternating electric field with a strength of 6 kV / cm, the birefringent pattern (frequency of 50 Hz) completely disappears in crossed polaroid microscopes. At 9 oh. With full properties

orientation takes about 30 s, npiT 94 ° C in 8-10 s. The homeotropic texture thus obtained is maintained when the sample is cooled in an electric field to room temperature.

Thus, polymers containing cyaniphenyl groups are capable of orientation in an electric field, which occurs at significantly lower temperatures (60-90 ° C)

0 compared to known polymers (190-.); maintaining orientation while cooling polymers in an electric field to room temperature.

five

These polymers, which are capable of orientation in an electric field, can be used to produce polaroid filters and optical filters, which are used in various kinds of optical devices, as well as in optical display devices. liquid crystal polyacrylates and polymethacrylates containing cyaniphenyl groups

Claims (1)

Claim Liquid crystalline polyacrylates and 'polymethacrylates containing cyandiphenyl groups of the general formula - -H ₂ (! - C (R) —------- --_ o R' I where y-N, -CH _g ; in z-i; x = -O- -CH ^ -.- Coo60 with an intrinsic viscosity of 0.06 to 0.30 (tetrahydrofuran, 30 ° C), which are capable of orientation in an electric field.