CS238940B1 - Process for the production of copolymers of propylene with polyethers - Google Patents

Abstract

Production of propylene copolymers with polyethers. On polypropylene chains, in an environment that does not deactivate ions, cationic centers are generated by oligomeric dications, with which a solution of polyether or a mixture of polyethers is then allowed to react at a temperature of 250 to 350 K.

Description

The invention relates to the production of copolymers of propylene with polyethers by macroionic reactions. Polypropylene, isotactic, syndiotactic and atactic, is one of the most hydrophobic polymers known.

This property limits some of its uses. For example, it cannot be dyed, it displaces stabilizers, and it is not compatible with almost any other polymer or filler. Isotactic polypropylene is produced in significant quantities and is relatively inexpensive.

Expanding the range of its applications is of significant economic importance, as it will enable the replacement of some expensive special materials and/or the production of new quality items.

For a significant part of the applications of polypropylene (and generally most polyalkenes), it would be desirable to introduce a certain degree of hydrophilicity into it, preferably a controllable variable one (controlled for a given purpose).

The above disadvantages would thus be suppressed or eliminated. The hydrophilicity of polymers is caused by the presence of electronegative heteroatoms - such as nitrogen, oxygen and, to a lesser extent, fluorine - capable of forming hydrogen bonds.

FROM

The introduction of such atoms into polypropylene chains is very difficult. Polypropylene is produced by coordination polymerization on Ziegler-Natta catalysts, whose activity ceases in the presence of substances containing nitrogen, oxygen, sulfur and, to some extent, fluorine.

Monomers with these atoms act as catalytic poisons and copolymerization with polar monomers is not possible. The hydrocarbon chain of the finished polyalkene is chemically stable, inert. Additional defined chemical modification of polypropylene is therefore also very difficult and requires special procedures.

For example, polypropylene powder is ozonized. The resulting hydroperoxide groups can be used to initiate emulsion polymerization of hydrophilic monomers. Graft copolymers are formed.

In Czechoslovak Patent Application No. 220422, the modification of polypropylene is described, namely by the interaction of oligomeric dications with polypropylene and subsequent cationic polymerization of oxygen-, nitrogen- or fluorine-containing monomers.

In this way, only copolymers of polypropylene with cationically polymerizing monomers can be obtained. It has now been found that copolymers of polypropylene with polyethers can be obtained if a polyether solution is used in the above reaction instead of the monomer.

The subject of the invention is a method for producing propylene with polyethers, in which polypropylene with cationic centers introduced by means of oligomeric dications is treated at a temperature of 250 to 350 K with a solution of a polyether or a mixture of polyethers, while excluding substances competing with the polyethers in the reaction with the cationic centers.

• The subject matter of the invention formulated in this way is the most concise expression of the complex events taking place in the modification process. Polypropylene reacts with the dication on metal-polymer bonds (present as residues of coordination centers after polymerization of propene), on chain defects (for example, c bonds) or on other reactive sites of the chains to form cationic centers.

Exchange reactions take place at these centers upon contact with the polyether, which can be schematically represented by the equations /wnnJ denotes the polypropylene chain; ©•'νννιφ oligomeric dication;

' 0 half-chain; cationic center; UVU> or —copolymer/:

η_!Τ_π_π_π_ + shaaó® hjhjv vvvvv© * ® ντιη^ττίΓ

-LTiririr?

TJTJT_nJVV© + O U-LTLTIA/

O · ® ΈΓυννΟν ⁺ ©/-v ?

?

/VO +·

-LTLnjl_rL· ⁺ © .rirv *- ίττιπ

Cationic centers on polypropylene chains arise from the interaction of polyalkene λ with dications, for example, the siloxonium type:

b®^í/ch ₃ / ₂ - o - sí/ch ₃ /- o-sí/ch ₃ / ₂ B® where & is a paired ion, such as CIO®, Asi®, Sbř^, Pl^etc., n is 4 to 10 octamethylene-bis-dioxolenylium eP - ového:

ch ₂ -.0 ©: _> ^c - /°¼ CH,—

- CH„

CH, bis /iP/ p xylene - ·.< , diylium :

CH ² VJ

CH, and other dications of this type from alpha, omega dihalohydrocarbon and the corresponding silver salt of the superacid /A^ #(,

From dications formed from tetrahydrofuran or oxepane oligomerized with fluorosulfonic acid anhydrides: cf ₃ SO F S0 ₃ 'O CF, so/^ , F SO ₃ *^*

I which are described in Polymer Preprints' 13, 1, 66 /1972/, J. Macromol. Sol 17 /7/ 1399 /1973/, or dilkationes arising from the decomposition products of diazonium salts during the polymerization of tetrahydrofuran /for example from 4-chlorophenyldiazonium hexafluorophosphate/

PIg is formed by the macromolecules. Chem. 177 3545 / 1976 /

As examples of modifying polyethers, it is possible to mention poly(dimethylene oxide) /polyethylene oxide/ and poly(1-methylethylene oxide); poly(chloromethylethylene oxide) /poly(trimethylene oxide) /poly(3,3 bis chloromethyloxetane) poly(tetramethylene oxide) /polytetrahydrofuran/; poly(hexamethylene oxide) /polyoxepane/ and substituted derivatives of these polyethers.

The degree of hydrophilicity can be controlled by the number of electronegative sites and the distance between them in the copolymer, both by the length of the blocks or grafts with heteroatoms, and by the type of polyethers. The preparation of the copolymer according to the present invention is particularly advantageous if the polyether is formed in a manner other than cationic.

The illustrated processes can be carried out technically relatively simply and with good yield. The invention will be illustrated by the following examples.

Example

To 1.5 g of polypropylene dried in the main branch of a double reactor on a high vacuum line, 0.18 mmol of siloxane dications with paired anions ClO^ are added using a syringe in a countercurrent flow of dry nitrogen.

Meanwhile, 0.5 g of polydimethylene oxide (molecular weight) is dried in the side branch of the reactor.

-i weight 6000/ in 20 cm' of tetrahydrofuran, namely with metallic sodium. After 24 hours of interaction of polypropylene with the dication, the polyether solution is added to it and the mixture is left to react at laboratory temperature for 144 hours.

» .After cutting the reactor, the polyether homopolymer is extracted from the mixture with water. 1.74 g of product is obtained, which is wetted with water.

Example 2

The procedure was as in Example 1, but instead of polydimethylene oxide, polytetramethylene oxide (polytetrahydrofuran) with a molecular weight of 17,500 was used. After extraction in hot isopropanol, 1.65 g of product was obtained, due to the lower hydrophilicity of polytetramethylene oxide, which was only partially wettable with water.

More significant than the increase in hydrophilicity is the decrease in melt viscosity, caused by the presence of polytetramethylene oxide blocks melting at low temperature.

Example 3

The procedure was as in Example 1, but instead of polydimethylene oxide, poly(chloromethyloxirane) (polyepichlorohydrin), dried with CaH ₂ , was used. After extraction in acetone, 1.8 g of product was obtained.

It was characterized by both increased hydrophilicity /compared to polypropylene/ and the content of C - Cl bonds, which allow further modifications by polymer-analogous reactions with macroions.

Example 4

The procedure was as in Example 1, a solution of a mixture of polydimethylene oxide and polychloromethyloxirane was introduced to the cationic centers on polypropylene. The product was well wettable with water and enabled further polymer-analogous reactions with macroanions.

Example 5

The procedure was as in Example 1, but instead of the siloxane dication, a bis p-xylene - oí. , oť diyl dication with ClO^® pair ions was used. The product was identical in wettability to the product of Example No. 1.

Claims (1)

SUBJECT OF THE INVENTION A process for the preparation of copolymers of propylene with polyethers, characterized in that it is converted into polypropylene with cationic polymers. Centers introduced through oligomeric dications act at a temperature of 250 to 350 K with a polyether solution or a mixture of polyethers to eliminate competing polyethers in the reaction with the cationic centers.