SU1650656A1 - Polysiloxaneurethanes as binding agents for manufacturing of gas permeable membranes - Google Patents

Abstract

This invention relates to polysiloxane-nuritanes (PPS) suitable for the manufacture of gas separation membranes (M). The invention makes it possible to increase the hydrolytic stability of M by using a POC of the ORiOCONHR2NHCO x Pz structure (5 (CH3 OSi (CH3) (CH2) m R3CONHR2 MHCO y, where Ri: -CH2CH (CH3) CH2-; -CH2 (CH3) 2 -CHN -: - СН2С (С2Н5) 2СН2-; CH2C (CH2CI -CH2-; - (СН2) 2-СБН4; -СНзСН-СНг -,) 2 (СНСН) 2; CeHio bCH2-; Ra: -O-, -S- n 6-19; m 1-4; x 1-3; at 1-4, with a mol.m. 31 000 - 105 000.3 table.

Description

The invention relates to new polymers, more specifically to polysiloxanurethanes, which can be used as materials for gas separation membranes with enhanced hydrolytic stability in aggressive media, and can be used in the chemical industry.

The purpose of the invention is to obtain polysiloxanurethanes, which can be used to create gas separation membranes with enhanced hydrolytic stability in aggressive media.

The goal is achieved by a new chemical structure, which is expressed by the general formulain., Cm3

, OCN-RrNC- | -r K CH W HjOS,) n (CH2V th. O NOЈ „,

He is noJ CH;

-R3CN-R2 NC-Rr-CH2CHC L -OM2C-CMr,

CrH5CH.CI MS3 CM,

-CH-C-CH

CH2C CH, -CH2-Q. SI, -.

ON SYA O O SL O

cn5

CHjCl

-sne-ciiciijSM- CH,

I I 3

ns -sn-, -si-si, axis

SI,

-CH-CHjCHj- ;. RT / VciL / L- .O- -

IV - / N-

- 5 4; l-c,: .H2O-:

Оos ™ g

R3 - -0 -.-- S-: n 6-19; m 1-4; x is 1-3; at 1-4, mol. 31000-105000 m

In the synthesis of these polysiloxautanes, aliphatic branched compounds having primary and secondary hydroxyl groups, for example, 2,2-dimethyl-1,3-propan-diol, 2-methyl-1,3-pro-, are used as low-molecular diols. pandiol, 2,2-diegil-1,3-propanediol, 1,4-hydroxymethylcyclohexane, 2,3-butanediol, dipropylene glycol, 1,2-propylene glycol, 1,3-butanediol, 2,2-di (chloromethyl} -1,3-pspanediol. Branched diols are available industrial products used in a herbal way to make polyesters.

The oligodimethylsiloxanes used are carbo-functional compounds in which the terminal OH and SH groups are bonded to silicon through a hydrocarbon chain. Their mol.m. 730-1800 (preferably 1000-1400).

As organic diisocyanates, aromatic, fatty aromatic and alicyclic compounds are used: 4,4-diphenylmethane-, 4,4-dicyclohexylmethane-, 1,5-naphthylene-, 2,4-toluidine-, 1,4-phenylene -, 1,5-xylylene diisocyanate.

Polysiloxanurethan get one-or two-stage method. In the first case, the reaction is carried out directly and the interaction of the organic diisocyanate with a mixture of low molecular weight diol of branched structure and oligodimethylsiloxane. In the second, the diol is reacted with a silicone prepolymer having terminal NCO groups. Prepolymer is preliminarily prepared on the basis of oligodimethylsiloxane and an excess of diisocyanate in the melt at 80–100 ° C (molar ratio of components 1: 1.5–2, which corresponds to the conversion of NCO – rpynn 50–67%). Free isocyanate groups are determined chemically.

The polymerization reaction is carried out at 35-80 ° C for 2-4 hours in the presence of .0.01-0.1 wt.% Organotin catalyst in an aprotic organic solvent medium — methylene chloride, ethyl acetate, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane. .

0

5 0 5

0

five

0 5 0

five

The isolation of polymers from the reaction mixture is achieved by precipitating in water or another precipitant or by evaporating the solvent. The yield of polymers is quantitative (94.7-99.2%).

Polysiloxanurethanes, which are white powdery or flaky substances, are well soluble in chlorinated hydrocarbons (chloroform, methylene chloride), complex ethers (ethyl acetate), ketones (acetone, methyl ethyl ketone), amide solvents (dimethylformamide),

The structure and composition of the synthesized polysiloxanurethanes was confirmed by elemental analysis, PMR and IR spectroscopy. In the IR spectra, characteristic absorption bands, corresponding to C – N vibrations (1350,1300 cm), have been identified; N-H (3340-3320), (1730 cm-1), C-0 (1080-1060) in the urethane group; С-Н in aliphatic groups (2960. 2870); C — H in aromatic groups (770); SI- 0 (1050-1020), SI-C (1260, 820-810) in dimethylsiloxane groups.

Example 1. In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a tube for the introduction of argon, 4.120 g (4.905 10 3 mol) of oligodimethylsiloxane (mol.m. 840) and 1.839 g (7.358 mol) of 4,4-diphenylmethanediisocyanate The contents of the flask are heated to 90 ° C and kept at this temperature for 80 minutes. The content of NCO-groups in the prepolymer is 3.53% (3.46% is calculated). After cooling to 20 ° C, a solution of 0.0013 g of tin octoate in 4 ml of freshly distilled ethyl acetate is added to the reaction mixture, and then a solution of 0.255 g (2.452 mol) of 2,2-dimethyl-1 is introduced from a dropping funnel over 5 minutes, 3-propane diol in 7 ml of ethyl acetate. Then the reaction mixture is heated to 50 ° C and kept for 2.5 hours at this temperature. After completion of the reaction, the polymer is isolated by precipitation into water and dried in vacuum at 50 ° C to constant weight. The polymer yield of the general formula (0 (t 3; n 9; x 1; y 2) is 6.1 g (98.0% of theoretical), the reduced viscosity is 0.52 dl / g (determined for solution 0, 5 g of polymer in 100 ml of Dioksang at 25 ° C), mol. M. 48800. Elemental analysis data.

Found%: Si 21.61,

Calculated,%: Si 22.00.

Example 2

The flask is charged with 58.320 g (46.29-10 3 mol) of oligodimethylsiloxane (mol.m. 1260), 4.810 g (46.29 mol) of 2.2-dimethyl-1,3-propanediol, 0.034 g of tin dibutyldylurinate and 50 ml of freshly distilled methylene chloride . The reaction mixture is heated to 3 ° C and a solution of 23.140 g (92.57 mol) of 4,4-diphenylmethanediisocyanate in 70 ml of methylene chloride is added to it via the dropping funnel within 10 minutes. The mixture is then kept at 35-40 ° C for 3 hours, after which 2 ml of ethanol is added. The isolation of the polymer from the reaction solution is carried out by evaporation of a volatile solvent. The yield of the polymer of general formula (I) (t 1; n 14.5; x 1; y 1) is 84.0 g (9.7.4% of the theoretical), 7dr 0.98 dl / g, mol.m. 105000. Elemental analysis data.

Found%: Si 22.97.

Calculated,%: Si 23.42.

In tab. 1 shows examples of the synthesis of polysiloxane (examples 1-12), carried out according to the method similar to example 2. as well as their main characteristics.

Films for subsequent tests are obtained from 10% solutions of polymers in chloroform having a thickness of 100 microns.

The hydrolytic stability of film samples is estimated by weight loss and a decrease in strength at break when they are aged in 10% aqueous solutions of HNOa and NaOH at 25 ° C (Table 2).

Claims (1)

In tab. 3 shows the results of tests of gas separation and deformation-strength properties of membranes based on polysiloxanurethanes. Gas permeability coefficients are determined by gas chromatographic method at 25 ° C. Mechanical tests are carried out on a Paulmeter dynamometer at 25 ° C. Formula of Invention Polysiloxanurethanes of General Formula SI, CH, II OR, OCN Rj-KC- | -R3 (CH, Si (CH, yoSi) n (cH2) m- OH BUT with | CCH, BUT he I CH3 five  -RaQN-R Nc-kg-sp2snsng-.-Ch2s-sn2-; cm, I SI, SL CH, C) -СНгС-СНг -: - СН. С-С1 ,, - СН7Х-СН: -, - СНз 0 cn5 -CHCHjI CH, C1 CH, CH, ,, 3 -sn -sn-. sk-mon, osn, -sn,. I g g I CH3CH3 -sn-snsi2--, i- / L-siG sn, ch -O-CH ..- With J , n. - Basic O-3--0-, -S-; n 6-19; m 1-4; x 1-3; y - 1-4, mol. 31000-105000 as a binder for the preparation of gas separation membranes. Table continuation Table 2 Table3