Polymers of unsymmetrically substituted 1,4-dioxane-2,5-diones
First Claim
1. A method of forming a polymer containing more than 2% by weight of recurring units of the formula:
- ##STR19## and the remaining units are ##STR20## where R1 and R2 are not the same as R3 and R4, R1 has at least one carbon atom, and R1, R2, R3, R4, R5, and R6, are separately selected from the group consisting of hydrogen and the radicals methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclohexyl, and phenyl which comprises heating, in the presence of a catalyst, at least 2% by weight of an unsymmetrically substituted 1,4-dioxane-2,5-dione of the formula;
##STR21## where R1, R2, R3 and R4 are defined as above and at least one compound of the formula;
##STR22## where R5 and R6 are defined as above.
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Abstract
Unsymmetrically 3,6-substituted 1,4-dioxane-2,5-diones may be polymerized to give living-tissue absorbable, hydrolytically degradable surgically useful polymers. These polymers have predominantly regular rather than random spacings of side chains, may be stereoregular and tend toward higher crystallinity than randomly sequenced polymers. A polymer of 3-methyl-1,4-dioxane-2,5-dione has the same empirical formula as an equimolecular copolymer of lactic and glycolic acid but has unique physical properties resulting from its more regular steric configuration. Polymers and copolymers of 3- and 3,6-unsymmetrically substituted 1,4-dioxane-2,5-diones have surgically useful mechanical properties. On implantation, in living mammalian tissue, the polymers are absorbed, and replaced by living tissue.
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Citations
5 Claims
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1. A method of forming a polymer containing more than 2% by weight of recurring units of the formula:
- ##STR19## and the remaining units are ##STR20## where R1 and R2 are not the same as R3 and R4, R1 has at least one carbon atom, and R1, R2, R3, R4, R5, and R6, are separately selected from the group consisting of hydrogen and the radicals methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclohexyl, and phenyl which comprises heating, in the presence of a catalyst, at least 2% by weight of an unsymmetrically substituted 1,4-dioxane-2,5-dione of the formula;
##STR21## where R1, R2, R3 and R4 are defined as above and at least one compound of the formula;
##STR22## where R5 and R6 are defined as above. - View Dependent Claims (2)
- ##STR19## and the remaining units are ##STR20## where R1 and R2 are not the same as R3 and R4, R1 has at least one carbon atom, and R1, R2, R3, R4, R5, and R6, are separately selected from the group consisting of hydrogen and the radicals methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclohexyl, and phenyl which comprises heating, in the presence of a catalyst, at least 2% by weight of an unsymmetrically substituted 1,4-dioxane-2,5-dione of the formula;
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3. A polymer containing more than 2% by weight of recurring units of the formula:
- ##STR23## and the remaining units are ##STR24## where R1 is CH3 - or H-.
- View Dependent Claims (4, 5)
Specification