Abstract Synthetic absorbable sutures are prepared from copolyoxalate polymers having isomorphic sequences. The polymers are derived from mixtures of cyclic and linear diols, each having the same carbon chain length of 6 or 8 atoms. The cyclic diol may be aliphatic or aromatic. The diols are polymerized with dialkyl oxalate, preferably in the presence of an inorganic or organometallic catalyst, to obtain a highly crystalline isomorphic copolyoxalate polymer which is melt extruded and drawn to form oriented filaments. The filaments are characterized by good initial tensile and knot strength and a high order of softness and flexibility. When implanted in living animal tissue, the fibers have good strength retention over a period of at least 21 days and eventually absorb with a minimal degree of adverse tissue reaction.
Isomorphic polyoxalate polymers consisting essentially of units of cyclic and linear oxalates and having the general formula ##STR3## wherein each R is ##STR4## and from about 5 to 95 mol percent of the R units are I; A is trans 1,4-cyclohexylene or p-phenylene, n is 1 or 2 and is the same for I and II, and x is the degree of polymerization resulting in a polymer having an inherent viscosity of at least 0.3 as determined on a 1 gm per liter solution of polymer in chloroform or hexafluoro-isopropanol at 25° C.
Claim 2
Dependent Claim
93 words
Isomorphic polyoxalate polymers consisting essentially of units of cyclic and linear oxalates and having the general formula ##STR3## wherein each R is ##STR4## and from about 5 to 95 mol percent of the R units are I; A is trans 1,4-cyclohexylene or p-phenylene, n is 1 or 2 and is the same for I and II, and x is the degree of polymerization resulting in a polymer having an inherent viscosity of at least 0.3 as determined on a 1 gm per liter solution of polymer in chloroform or hexafluoro-isopropanol at 25° C.
Claim 3
Dependent Claim
14 words
The polymer of claim 1 wherein n is 1 and A is trans 1,4-cyclohexylene.
Claim 4
Dependent Claim
14 words
The polymer of claim 1 wherein n is 2 and A is trans 1,4-cyclohexylene.
Claim 5
Dependent Claim
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The polymer of claim 1 wherein from 40 to 75 mol percent of the R groups are comprised of units of formula I.
Claim 6
Dependent Claim
13 words
The polymer of claim 1 wherein n is 1 and A is p-phenylene.
Claim 7
Dependent Claim
13 words
The polymer of claim 1 wherein n is 2 and A is p-phenylene.
Claim 8
Dependent Claim
14 words
A polymer of claim 1 having an inherent viscosity of at least about 0.5.