CS257650B1 - 3-cyanopropyl-containing polysiloxanes - Google Patents

Abstract

Polysiloxanes containing a 3-cyanopropyl group can be prepared by the addition of allyl cyanide to poly(hydrogen(methyl)siloxanes) with an average molecular weight of 500 to 20,000 and a hydrogen content of 0.04 to 1.6 wt. %. These new substances are suitable for the treatment of the surface of materials and the treatment of chromatographic sorbents and columns.

Description

The invention relates to 3-cyanopropyl-containing polysiloxanes.

It is known that polysiloxane oils are used in technical practice, including those containing Si-H bond, because they allow long-term hydrophobization of paper and textiles and are components of so-called liquid silicone rubbers (eg Stark FO ·, in the book Comprehensive Organometallic Chemistry, Vol. 2, p. 395, Pergamon Press 1982).

However, these oils are currently only available in the form of dimethyl (methylhydrogen) siloxane copolymers, which have recently been modified by a non-polar alkyl or phenoxypropyl group. However, for some purposes (e.g., to modify chromatographic materials), it would be desirable that the polysiloxane oils containing the Si-H bond also contain a polar group.

The compounds of the invention suitably meet this requirement.

The present invention provides polysiloxanes containing a 3-cyanopropyl group formed by the addition of allyl cyanide cyanide to poles (hydrogen (methyl) siloxanes) having an average molecular weight ranging from 500 to 20,000 and a hydrogen content of 0.04 to 1.6 wt. %.

This addition, illustrated by the reaction scheme of CH, CH,

II (CH3), S1- (O-Si-) - (O-Si) -OSi (CH3), + z CH, = CH-CH, CN- ^JJ | ^χ | ytt ^CH 3 ^H

CH, (CH 2), Si- (O-Si-) - (O-Si) - (O-Si | j | x | y-z |

CH, H

-) _from -Si (CH ₃ ) ₃ can be carried out under similar conditions to the hydrosilylation of allyl cyanide with monomeric silanes.

This addition can be carried out by catalysing transition metal complexes or compounds at not very elevated temperatures, preferably at 50 to 150 ° C. The most commonly used catalyst is chloroplatinic acid or rhodium complexes, for example tris (triphenylphosphane) rhodium complex. The reaction can be carried out in aprotic solvents, preferably without solvent. The relative ratio of the reactants is primarily determined by the degree of conversion of the Si-H bonds, since the presence of a portion of the Si-H bonds after addition is preferred for some applications, since they allow anchoring of silicone oils to the surfaces of the treated materials. For other applications, the absence of Si-H bonds increases oil stability.

The following examples illustrate the polysiloxane oils of the invention without limiting or limiting them.

He did

To 91 g of poly (hydrogen (methyl) siloxane) having an average molecular weight of 500 and a hydrogen content in the form of Si-H bonds of 1.6 wt. 70 g of allyl cyanide and 2 ml of a 0.1 M solution of chloroplatinic acid in isopropanol were added. The mixture was heated to 100 ° C for 5 h. Thereafter, unreacted allyl cyanide was distilled off to obtain a viscous polysiloxane oil containing hydrogen in the form of 0.5 wt% Si-H bonds. %. In its infrared spectrum (in substantia) were found bands corresponding to valence vibrations of siloxane bonds (1,088 and 1,031 cm ^), valence vibrations of CH bonds (at 2,953 cm ^), valence vibrations of Si-H bonds at 2,152 cm and sharp band at 2 241 cm due to vibration of the nitrile group.

Example 2

To 60 g of a hydrogen (methyl) dimethylsiloxane copolymer having an average molecular weight of 20,000 and a hydrogen content in the form of Si-H bonds of 0.04 wt. 8 g of allyl cyanide with 1 ml of a 0.1 M solution of chloroplatinic acid in tetrahydrofuran was added and the mixture was heated to 120 ° C for 6 h with stirring. The volatiles were then removed by distillation under vacuum, no Si in the product. -H bonds, in the infrared spectrum of the viscous oil thus prepared, the bands mentioned in the previous example were found except for the band corresponding to the vibrations of the Si-H bonds.

Claims (1)

SUBJECT OF THE INVENTION Polysiloxanes containing 3-cyanopropyl group transportable by addition of allyl cyanide to poly (hydrogen (methyl) siloxanes) having an average molecular weight of 500 to 20,000 and a hydrogen content of 0.04 to 1.6 wt. %.