Silicone copolymers, methods of making, and articles

1. A copolymer composition comprising:

a random silicone copolymer having a backbone composition comprising:

silicone segments in an amount of 5 wt-% to 40 wt-%, based on the total weight of the copolymer;

hydrophilic segments in an amount of 40 wt-% to 75 wt-%, based on the total weight of the copolymer; and

reinforcing segments in an amount of 5 wt-% to 30 wt-%, based on the total weight of the copolymer, wherein the reinforcing segments are derived from the reaction of one or more chain extenders with one or more multi-functional isocyanates, multi-functional carboxylic acids, multi-functional anhydrides, multi-functional esters, or multi-functional acid halides;

wherein the silicone segments, hydrophilic segments, and reinforcing segments are connected randomly through urea, urethane, amide, and/or oxamide linkages;

wherein the hydrophilic segments and the reinforcing segments are present in a weight ratio of 1.8:1 to 8:1; and

wherein the hydrophilic segments and the silicone segments are present in a weight ratio of 1.3:1 to 4.5:1; and

wherein the copolymer composition further comprises a hydrophilic polymer.

2. The copolymer composition of claim 1 wherein the hydrophilic segments comprise polyethylene glycol groups, polypropylene glycol groups, polybutylene oxide groups, polyester groups, amine-terminated polyester groups, amine-terminated polyamide groups, polyester-amide groups, polycarbonate groups, or combinations thereof.

3. The copolymer composition of claim 2 wherein the hydrophilic segments comprise polyethylene glycol groups in an amount of 40 wt-% to 75 wt-%, based on the total weight of the copolymer.

4. The copolymer composition of claim 3 wherein the backbone composition comprises polypropylene glycol segments in an amount of up to 10 wt-%, based on the total weight of the copolymer.

5. The copolymer composition of claim 1 wherein the number average molecular weight of the silicone segments is at least 1,000 grams/mole.

6. The copolymer composition of claim 1 wherein the number average molecular weight of the hydrophilic segments is at least 1,000 grams/mole.

7. The copolymer composition of claim 1 wherein the silicone segments comprise (—Si(Me) 2 -O—) m groups, wherein m is an integer ranging from 2 to 900.

8. The copolymer composition of claim 1 wherein the hydrophilic segments have a formula according to Formula I or Formula III:

—CH 2 —CH 2 —[—O—CH 2 —CH 2 ] x -  (I)

—[—CH(CH 3 )—CH 2 —[—O—CH 2 —CH(CH 3 )—] w —[—O—CH 2 —CH 2 —] x —[—O—CH 2 —CH(CH 3 )—] y ]—   (III)

wherein x is an integer ranging from 2 to 60, and the sum of w and y is an integer ranging from 2 to 8.

9. The copolymer composition of claim 1 wherein the one or more multi-functional isocyanates are selected from the group of aromatic multi-functional isocyanates, cycloaliphatic multi-functional isocyanates, aliphatic multi-functional isocyanates, and araliphatic multi-functional isocyanates, used either alone or in mixtures of two or more.

10. The copolymer composition of claim 1 wherein the one or more chain extenders comprise one or more chain-extending (C3-C12)multi-functional amines.

11. The copolymer composition of claim 1 further comprising an antioxidant.

12. The copolymer composition of claim 1 further comprising an active agent.

13. The copolymer composition of claim 1 further comprising an elutable surfactant and optionally a surfactant carrier.

14. The copolymer composition of claim 13 further comprising a surfactant carrier selected from polyalkylene oxides, polyhydric alcohols, esters of polyhydric alcohols with (C1-C18)alkyl carboxylates optionally substituted with hydroxyl groups, (C2-C18)esters of polycarboxylic acids, and mixtures thereof.

15. The copolymer composition of claim 1 which demonstrates less than 20% by weight of total leached compounds after sterilizing with gamma irradiation up to 50 kGy and aging for a period of 6 months at 23° C.

16. An article comprising the copolymer composition of claim 1 .

17. The article of claim 16 which is a disposable surgical wound edge protector, a surgical retractor, or a surgical sponge.

18. A method of making a copolymer composition, the method comprising:

forming a random silicone copolymer by combining components comprising:

a silicone segment precursor in an amount of 5 wt-% to 40 wt-%, based on the total weight of the silicone copolymer;

a hydrophilic segment precursor in an amount of 40 wt-% to 75 wt-%, based on the total weight of the silicone copolymer; and

one or more chain extenders and one or more multi-functional isocyanates, multi-functional carboxylic acids, multi-functional anhydrides, multi-functional esters, or multi-functional acid halides in amounts sufficient to form reinforcing segments in an amount of 5 wt-% to 30 wt-%, based on the total weight of the silicone copolymer;

wherein the silicone segments, hydrophilic segments, and reinforcing segments are connected randomly through urea, urethane, amide, and/or oxamide linkages;

wherein the hydrophilic segments and the reinforcing segments are present in a weight ratio of 1.8:1 to 8:1; and

wherein the hydrophilic segments and the silicone segments are present in a weight ratio of 1.3:1 to 4.5:1.