| 摘要 |
In accordance with an aspect of the invention, methods of forming medical articles are provided, which comprise (a) preparing a melt phase that comprises a molten polymer and a supercritical fluid, (b) forming a polymeric region from the melt phase, and (c) cooling the polymeric region. In certain embodiments, the supercritical fluid is formed from chemical species (e.g., CO2, propane, etc.) that are gases at room temperature (25° C.) and atmospheric pressure (1 atm). According to another aspect of the present invention, medical articles are provided which comprise melt-processed polymeric materials. The polymeric materials have a composition that cannot be melt processed without the use of melt-viscosity reducing additives due to thermal degradation, and yet the polymeric material does not contain such additives.
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