摘要 |
Soft, non-blocking, thermoplastic polyurethanes are prepared by reacting a long chain polyester or polyether diol, a short chain diol, a diisocyanate and a silicone diol of the formula: <IMAGE> wherein x has a value of about 1 to 30, y has a value of about 1 to 200, R is an alkylene group having 2 to 4 carbon atoms, R1 is selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 18 carbon atoms, a phenyl group, a substituted phenyl group, or a phenylalkyl group, and V and W are divalent linking groups. A unique feature of the invention is that the polymers exhibit, less blocking, are less susceptible to hydrolysis and are highly transparent. These polyurethanes are particularly useful in fabricating medical tubing.
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