Zwitterionic polysiloxane for biomedical devices
A zwitterionic polysiloxane polymer (e.g., a polyurethane elastomer) composition having poly(dialkylsiloxane) blocks and a zwitterionic moiety is prepared by the copolymerization of a poly(dialkylsiloxane) diol, a diisocyanate, a tertiary amine alkyl diol, and a poly(dialkylsiloxane) diamine to form a poly(urethane urea) copolymer. A substituted saturated heterocylic compound is reacted with the tertiary amine of the poly(urethane urea) copolymer to introduce a zwitterionic group into the poly(urethane urea) copolymer backbone. A polysiloxane polymer having a zwitterionic moiety is prepared by reacting a diallyl tertiary amine compound and a substituted saturated heterocylic compound to form a diallyl zwitterionic macromer and cross-linking a vinyl terminated poly(dialkylsiloxane) and the diallyl zwitterionic macromer with a curing agent to introduce a zwitterionic group into the poly(dialkylsiloxane) polymer.
1 . A method of preparing a polysiloxane composition comprising a zwitterionic moiety, the method comprising:
reacting a diallyl tertiary amine compound with a substituted saturated heterocyclic compound to produce a diallyl zwitterionic monomer, mixing a vinyl-terminated poly(dialkylsiloxane) and the diallyl zwitterionic monomer with a curing agent, and curing the mixture to introduce a zwitterionic group into the poly(dialkylsiloxane); or
mixing a vinyl-terminated poly(dialkylsiloxane) and a diallyl tertiary amine compound with a curing agent, curing the mixture to form a cross-linked tertiary amine-modified poly(dialkylsiloxane), and reacting the cross-linked tertiary amine-modified poly(dialkylsiloxane) with a substituted saturated heterocyclic compound to introduce a zwitterionic group into the cross-linked tertiary amine-modified poly(dialkylsiloxane).
2 . The method of claim 1 , comprising: reacting a diallyl tertiary amine compound with a substituted saturated heterocyclic compound to produce a diallyl zwitterionic monomer, mixing a vinyl-terminated poly(dialkylsiloxane) and the diallyl zwitterionic monomer with a curing agent, and curing the mixture to introduce a zwitterionic group into the poly(dialkylsiloxane).
3 . The method of claim 2 , wherein a molar ratio of vinyl-terminated poly(dialkylsiloxane) to the diallyl zwitterionic monomer is 1-5:1-12.
4 . The method of claim 1 , comprising:
mixing a vinyl-terminated poly(dialkylsiloxane) and a diallyl tertiary amine compound with a curing agent;
curing the mixture to form a cross-linked tertiary amine-modified poly(dialkylsiloxane); and
reacting the cross-linked tertiary amine-modified poly(dialkylsiloxane) with a substituted saturated heterocyclic compound to introduce a zwitterionic group into the cross-linked tertiary amine-modified poly(dialkylsiloxane).
5 . The method of claim 4 , wherein the diallyl tertiary amine compound has the structure:
wherein R 4 , and R 5 , are independently
where n is at least one, and R 6 is linear alkyl.
6 . The method of claim 1 , wherein the substituted saturated heterocyclic compound is selected from:
7 . The method of claim 1 , further comprising coating or fabricating an article with the polysiloxane composition, wherein the article optionally is a blood-contacting article.
8 . The method of claim 7 , wherein the blood-contacting article is a stent, a coil, a catheter, a vascular graft, an artificial valve, a gas-permeable membrane, or a microfluidic device.
9 . The method of claim 2 , wherein the diallyl tertiary amine compound has the structure:
wherein R 4 , and R 5 , are independently
where n is at least one, and R 6 is linear alkyl.
10 . The method of claim 4 , wherein a molar ratio of vinyl-terminated poly(dialkylsiloxane) to the diallyl tertiary amine compound is 1-5:1-12.
11 . The method of claim 1 , wherein the vinyl-terminated poly(dialkylsiloxane) comprises one or more of: a dimethyl siloxane; a diphenylsiloxane; a diethylsiloxane; a trifluoropropyl methyl siloxane; a phenylmethylsiloxane; a copolymer of dimethylsiloxane with one or more of a diphenylsiloxane, a diethylsiloxane, a trifluoropropyl methyl siloxane, a phenylmethylsiloxane; and/or an aminopropylmethylsiloxane-(dimethylsiloxane).