| 摘要 |
combination of at least two polyamides. The catheter component can be made from a blend of the two polyamides, or a co-extrusion of the two polyamides with an inner layer and an outer layer. The first polyamide has a Shore D durometer hardness of more than seventy seven (77), and can be selected from various transparent amorphous nylons having an amorphous segment such as an aliphatic segment, an aromatic segment, or a cycloaliphatic segment. The second polyamide has a lower durometer hardness than the first polyamide, and preferably less than 73, and can be a block copolymer of nylon and polytetramethylene glycol. Both polyamides have the same amide block or segment, e.g. nylon 12. Adding small amounts of the high hardness polyamide can reinforce the low polyamide at the amorphous segments, thereby increasing the overall strength of the material.
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