Polymer strand and process for producing a polymer strand
A process for producing a polymer strand involves: inserting a nucleation element into a pre-strand composition, the pre-strand composition comprising a polymer mixed with a solvent, the polymer having a concentration in the pre-strand composition that is greater than or equal to an overlap concentration (c*) of the polymer in the pre-strand composition; and, withdrawing the nucleation element from the pre-strand composition so that a strand comprising the polymer is pulled by the nucleation element from the pre-strand composition, the nucleation element being withdrawn at a rate such that a pull time (τ pull ) of the nucleation element is less than reptation time (τ rep ) required to relax polymer entanglements in the pre-strand composition, thereby inducing a viscoelastic response in the pre-strand composition as the strand is pulled by the nucleation element from the pre-strand composition.
1 . A process for producing a multifilament polymer strand of polyethylene oxide (PEO) and collagen, the process comprising:
inserting a nucleation element into a pre-strand composition comprising PEO and collagen mixed with a solvent; and,
withdrawing the nucleation element from the pre-strand composition so that a multifilament strand comprising PEO and collagen filaments is pulled by the nucleation element from the pre-strand composition.
2 . The process of claim 1 , wherein the pre-strand composition has a viscosity in a range of 100-400 Pa·s.
3 . The process of claim 1 , wherein the pre-strand composition has a viscosity in a range of 150-300 Pa·s.
4 . The process of claim 1 , wherein the PEO is present in the pre-strand composition in amount of at least 7 wt %, based on total weight of the pre-strand composition.
5 . The process of claim 1 , wherein the PEO is present in the pre-strand composition in amount of 7-14 wt %, based on total weight of the pre-strand composition.
6 . The process of claim 1 , wherein the PEO is present in the pre-strand composition in amount of 7-10 wt %, based on total weight of the pre-strand composition.
7 . The process of claim 1 , wherein the collagen is present in the pre-strand composition in amount of 0.2-9 wt %, based on total weight of the pre-strand composition.
8 . The process of claim 1 , wherein the collagen is present in the pre-strand composition in amount of 0.3-3 wt %, based on total weight of the pre-strand composition.
9 . The process of claim 1 , wherein the multifilament strand is pulled at a rate in a range of 0.5-4 m/s.
10 . The process of claim 1 , wherein the nucleation element has a surface, and the nucleation element is inserted into the pre-strand composition so that the surface of the nucleation element is wetted over a surface area of at least 11 mm 2 .
11 . The process of claim 1 , wherein the nucleation element is one nucleation element in an array of spaced-apart nucleation elements, neighboring nucleation elements in the array having a center-to-center spacing that is at least 2 times a diameter of a thickest neighboring nucleation element.
12 . The process of claim 1 , wherein the solvent is an aqueous solvent.
13 . The process of claim 1 , wherein the multifilament polymer strand produced by the process has a strand length in a range of 0.01-100 m.
14 . A process for producing a collagen strand, the process comprising:
inserting a nucleation element into a pre-strand composition comprising polyethylene oxide (PEO) and collagen mixed with a solvent;
withdrawing the nucleation element from the pre-strand composition so that a multifilament strand comprising PEO and collagen filaments is pulled by the nucleation element from the pre-strand composition; and,
separating the PEO from the collagen in the multifilament strand to produce the collagen strand.
15 . The process of claim 14 , wherein the multifilament strand is pulled at a rate in a range of 0.5-4 m/s.
16 . The process of claim 14 , wherein the nucleation element has a surface, and the nucleation element is inserted into the pre-strand composition so that the surface of the nucleation element is wetted over a surface area of at least 11 mm 2 .
17 . The process of claim 14 , wherein the nucleation element is one nucleation element in an array of spaced-apart nucleation elements, neighboring nucleation elements in the array having a center-to-center spacing that is at least 2 times a diameter of a thickest neighboring nucleation element.
18 . The process of claim 14 , wherein the solvent is an aqueous solvent.
19 . The process of claim 14 , wherein the multifilament strand has a strand length in a range of 0.01-100 m.