摘要 |
The present invention involves a method of processing polyacrylonitrile into a predetermined form. The first step in this method includes preparing a solution of a room temperature solvent that will dissolve polyacrylonitrile at room temperature and, a room temperature non-solvent that will not dissolve polyacrylonitrile at room temperature. The solution is prepared with sufficient non-solvent to render the room temperature solvent inoperable such that it will not dissolve polyacrylonitrile at room temperature and such that it will be operable at temperatures above 65° C. to dissolve polyacrylonitrile therein. The second step in the present invention method involves combining polyacrylonitrile with the solution to form a mixture, in an amount of at least 20%, by weight, of polyacrylonitrile, based on the total weight of the mixture. Preferred is about 20% to about 50% by weight of the polyacrylonitrile. The third step involves processing the mixture in a hot-melt processor at temperatures in excess of 65° C. to produce a polyacrylonitrile product. An optional fourth step, which would be useful in forming medical devices and related products, involves extracting solvent from the product by liquid extraction, e.g. warm water wash.
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