Ceskoslovenska Akademie Ved

Jiri Trekoval

Jiri Stamberg

Stanislav Sevcik

Jan Holata

Lubomir Lochmann

Otto Wichterle

Jiri Vacik

Jiri Michalek

Lubomir Lochman

Jiri Coupek

Miroslava Rodova

Hydrophilic three dimensional polymers, the prevailing mass of which is formed by structural units corresponding to monomers miscible with water at any ratio, and the method for their production, wherein one weight part of the monomers miscible with water is copolymerized, by the effect of free-radical initiators, with 0.01 to 1 weight part of a polyfunctional unsaturated oligomer, which is prepared with an average degree of polymerization x=3 to x=100 by the anionic polymerization of allyl methacrylate, with the contingent addition of methacrylonitrile or methacrylic esters of univalent saturated alcohols containing 1 to 4 carbon atoms or methacrylic esters of monohydroxy compounds containing at least one etheric oxygen atom in the chain, or where 0.7 to 1 weight part of monomers miscible with water is copolymerized with 0.01 to 0.3 weight parts of hydrophobic monomers of the alkyl methacrylate or acrylate type in the presence of an oligomeric crosslinking agent with at least two olefinic double bonds added in the amount of 0.01 to 0.1 weight parts, advantageously up to 0.05 weight parts, by the effect of free-radical initiators.

Hydrophilic three dimensional polymer and a method for production thereof

The invention relates to polymers and copolymers of pivaloyloxyalkyl methacrylates which contain structural units of the general formula ##STR1## where R.sup.1 is (CH.sub.2).sub.n.sbsb.1 --O (n.sub.1 =2 to 10) or (CH.sub.2 CH.sub.2 --O).sub.n.sbsb.2 (n.sub.2 =1 to 4) and to the method of their preparation and modification. The polymerization and copolymerization can be initiated by free-radical initiators of the peroxy type or by anionic initiators, e.g., alkali metal alkoxides or butyllithium, and carried out in a solution, bulk or suspension process in the presence of a crosslinking agent or without it. Anionic polymerization may result in stereoregular polymers or may be used for preparation of block copolymers by the 'living' polymer technique. The polymers and copolymers can be modified by the partial or total conversion of the pivaloyloxyalkyl methacrylate units into hydroxyalkyl methacrylate units by selective hydrolysis, alcoholysis or other reaction.

Polymers of pivaloyloxyalkyl methacrylates, method for their preparation

The invention pertains to a method for preparation of polymers, grafted polymers, and copolymers from olefins substituted by polar groups (ester, nitrile, or aryl) or from dienes, wherein the polymerization is initiated by the system formed by mixing of an organic amide of alkaline metal with an alkaline metal alkoxide. The organic amide is derived from primary or secondary amines or polyamines, or from tertiary polyamines containing at least one primary or secondary amino group. These amines contain N-C or N-Si bonds, 1-4000 C atoms and 1-1000 N atoms in a molecula, or have the molecular weight below 100,000. The alkoxides are derived from C.sub.3 -C.sub.16 alcohols. The polymerizations are carried out at -80.degree. to +80.degree. C. (advantageously at +20.degree. C.), at the monomer/organic amide molar ratio 5-1500, at the molar ratio alkoxide/amide 0.5-10, and in hydrocarbon or ether solvents. The advantage of organic amides of alkaline metals is the easy and economical preparation and suitable physical and chemical properties (solubility, higher resistance to contamination), while the alkoxide component exhibits the superadditive effect on the polymerization rate and yield and affects the microstructure of polymer. The method is also suitable for preparation of block copolymers by successive addition of various monomers, block copolymers with polyamine blocks, and grafted polyamine polymers.

Method for the preparation of polymers and copolymers of vinyl monomers

The invention relates to polymers and copolymers of pivaloyloxyalkyl methacrylates which contain structural units of the general formula ##STR1## where R.sup.1 is (CH.sub.2).sub.n.sbsb.1 --O (n.sub.1 = 2 to 10) or (CH.sub.2 CH.sub.2 --O).sub.n.sbsb.2 (n.sub.2 = 1 to 4) and to the method of their preparation and modification. The polymerization and copolymerization can be initiated by free-radical initiators of the peroxy type or by anionic initiators, e.g., alkali metal alkoxides or butyllithium, and carried out in a solution, bulk or suspension process in the presence of a crosslinking agent or without it. Anionic polymerization may result in stereoregular polymers or may be used for preparation of block copolymers by the 'living' polymer technique. The polymers and copolymers can be modified by the partial or toal conversion of the pivaloyloxyalkyl methacrylate units into hydroxyalkyl methacrylate units by selective hydrolysis, alcoholysis or other reaction.

The invention relates to anionic polymerization and copolymerization of methacrylate and acrylate esters and related polar monomers, e.g. acrylonitrile, by initiation with carboxylic acid esters formally substituted in the .alpha.-position with Li, Na, K, Rb or Cs and containing 3 - 30 C atoms in the straight or branched chain and 1 - 6 ester group in one molecule either alone or in the presence of C.sub.3 - C.sub.16 alkali metal alkoxide with the straight or branched chain. The polymerization or copolymerization is carried out at -80.degree. to +50.degree. C, advantageously at 20.degree. C and the molar ratios of monomers to .alpha.-metallo ester 10 to 1500 and alkoxide to .alpha.-metallo ester 0.5 to 80. Instead of the pure isolated .alpha.-metallo esters also a reaction mixture may be used which was prepared from the alkaline salt of substituted organic amide and non-metallated ester. Aliphatic, cycloaliphatic or aromatic hydrocarbons, organic ethers or their mixtures were used as solvents for both monomers and initiatora. The method is also suitable for preparation of block copolymers of the aforesaid monomers, if the second or further comonomer is always added after the completed polymerization of the preceding monomer and if the subsequent monomers are used either of the equal anionic polymerizability or in the sequence of their increasing anionic polymerizability.

Method for preparation of methacrylate and acrylate polymers and

Polymeric alkoxides based on hydroxyalkyl methacrylates consist of units ##EQU1## where X is the organic bivalent group with the straight or branched C.sub.2 --C.sub.20 chain and M is Li, Na or K. The polymer has advantageously a heterogeneous structure of a macroporous gel with the inner surface 0.5 - 500 m.sup.2 /g. Polymeric alkoxides are prepared by treatment of a homopolymer or copolymer containing hydroxyl groups with the necessary amount of an alkali metal organic compound dissolved in an aprotic solvent, to convert the hydroxyl groups. Alkyl, aralkyl or aryl C.sub.1 to C.sub.30 derivatives of Li, Na or K are used as the alkali metal organic compounds.

Polymeric alkoxides based on hydroxyalkyl methacrylates and a method for

The invention relates to new esters of carboxylic acids formally substituted in the alpha-position by sodium or potassium which have the formula

Esters of carboxylic acids formally substituted by sodium or potassium

A method for preparation of polymethacrylate esters by the anionic polymerization characterized by application of new initiation systems based on esters of .alpha.-lithio carboxylic acids having 2-30 carbon atoms in a straight or branched chain and 1-6 ester groups in a molecule, or on their adducts or complexes with lithium alkoxides having 3-16 carbon atoms in a straight or branched chain. The polymerization is carried out at temperatures -70.degree. to +50.degree. C, preferably at +20.degree. C, with the monomer - to - initiator ratio equal 10 to 1500. The polymers which have new mechanical and solution properties due to the new preparation method are suitable as additives into mineral oils increasing their viscosity indexes and suppressing their solidification temperature, as a cement in medical practice, and the like.

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Prague, Czechia

Jiri Trekoval