METHOD FOR PREPARING NANODIAMOND-CONTAINING THERMOPLASTIC FIBERS AND THE USE OF SUCH FIBERS IN YARNS AND FABRICS
The present disclosure relates to methods for preparing nanodiamond-containing thermoplastic fibers and filaments having diamond particles substantially uniformly distributed throughout. The process comprises melt extruding a material comprising a thermoplastic polymer and from about 0.001% to about 0.25% by weight nanosized diamond particles. The present disclosure also relates to yarns and fabrics comprising the nanodiamond-containing thermoplastic fibers or filaments, and to garments comprising these yarns and/or fabrics. Yarns and fabrics comprising nanodiamond-containing thermoplastic fibers and filaments have been found to have enhanced thermal properties, enhanced mechanical properties, and/or enhanced softness.
1 . A method for preparing a nanodiamond-containing thermoplastic fiber comprising:
melt extruding a material comprising
at least 98.0% by weight thermoplastic polymer, and
from about 0.001% to about 0.25% by weight diamond particles having particle sizes between about 2 and about 500 nm;
to produce a fiber having diamond particles substantially uniformly distributed throughout the fiber.
2 . The method of claim 1 , wherein the nanodiamond-containing thermoplastic fiber contains from about 0.005% to about 0.100% by weight diamond particles.
3 . The method of claim 1 , wherein the thermoplastic polymer is selected from the group consisting of: polyesters, polypropylene, polycarbonate, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polytrimethylene naphthalate (PTN), polyether ketone (PEK), polyether ether ketone (PEEK), poly(p-phenylene sulfide) (PPS), polyamides (nylon), thermoplastic polyurethanes (TPU), thermoplastic elastomers (TPE), and combinations thereof.
4 . The method of claim 1 , wherein the thermoplastic polymer comprises one or more polyamides.
5 . The method of claim 4 , wherein the thermoplastic polymer comprises nylon 6,6; nylon 6; or a combination thereof.
6 . The method of claim 1 , wherein the diamond particles have particle sizes between about 2 nm and about 10 nm.
7 . The method of claim 1 , wherein the melt extruding comprises at least the following two steps:
a. preparing diamond concentrate pellets comprising
a first thermoplastic polymer,
about 0.1% to about 10% by weight diamond particles, and
about 0.1% to about 1% by weight dispersion agent; and
b. preparing the nanodiamond-containing thermoplastic fiber by melt extruding a mixture of a second thermoplastic polymer and the diamond concentrate pellets prepared in step (a).
8 . The method of claim 7 , wherein the second thermoplastic polymer is a polyamide.
9 . The method of claim 8 , wherein the first thermoplastic polymer is a polyamide.
10 . The method of claim 9 , wherein the first thermoplastic fiber is nylon 6 and the second thermoplastic polymer is nylon 6,6.
11 . The method of claim 7 , wherein the first thermoplastic polymer and the second thermoplastic polymer differ from one another.
12 . The method of claim 7 , wherein the first thermoplastic polymer and the second thermoplastic polymer are the same.
13 . The method of claim 7 , wherein the dispersion agent comprises zinc stearate, calcium stearate, or a mixture thereof.
14 . The method of claim 7 , wherein step (a) comprises heating the first thermoplastic polymer to form a viscous phase, blending the nanodiamond particles and dispersion agent into the first thermoplastic polymer, and extruding the resulting mixture.
15 . The method of claim 7 , wherein step (b) comprises feeding pellets of the second thermoplastic polymer and the diamond concentrate pellets into an extruder in controlled quantities to produce a nanodiamond-containing thermoplastic fiber that contains a predetermined concentration of nanodiamond.
16 . The method of claim 1 , wherein incorporation of the diamond particles produces at least a 5% increase in the thermal conductivity of the fiber in contrast to the fiber without the diamond particles.
17 . The method of claim 1 , wherein incorporation of the diamond particles produces a substantial increase in the strength of the fiber over the fiber without the diamond particles, without producing a substantial decrease in elongation.
18 . A nanodiamond-containing thermoplastic fiber comprising:
about 99.0% to about 99.9% by weight thermoplastic polymer;
about 0.001% to about 0.25% by weight diamond particles, the diamond particles having particle sizes between about 2 and about 500 nm;
about 0.002% to about 0.02% by weight dispersion agent.
19 . The nanodiamond-containing thermoplastic fiber of claim 18 , wherein the thermoplastic polymer is nylon.
20 . The nanodiamond-containing thermoplastic fiber of claim 18 , wherein the dispersion agent comprises zinc stearate, calcium stearate, or a mixture thereof.
21 . The nanodiamond-containing thermoplastic fiber of claim 18 , wherein the nanodiamond-containing thermoplastic fiber comprises about 0.005% to about 0.100% by weight diamond particles.
22 . The nanodiamond-containing thermoplastic fiber of claim 21 , wherein the diamond particles have particle sizes between about 2 nm and about 10 nm.
23 . The nanodiamond-containing thermoplastic fiber of claim 18 , wherein the nanodiamond-containing thermoplastic fiber has at least a 5% higher thermal conductivity than a fiber containing only the thermoplastic polymer.
24 . The nanodiamond-containing thermoplastic fiber of claim 18 , wherein the nanodiamond-containing thermoplastic fiber has at least a 4% higher strength than that of a fiber containing only the thermoplastic polymer and an elongation that is within about 2% of that of the fiber containing only the thermoplastic polymer.
25 . The nanodiamond-containing thermoplastic fiber of claim 18 , further comprising about 0.001% to about 0.25% by weight sub-micron particles of boron nitride, graphite, graphene, silica, one or more aluminosilicates, or a combination thereof.
26 . A fabric comprising the nanodiamond-containing thermoplastic fiber of claim 18 .
27 . A garment comprising the fabric of claim 26 , the garment being configured to provide transfer heat away from a wearer's body.
28 . A method of increasing the thermal conductivity of a fabric comprising:
preparing a fiber having
at least 98.0% by weight thermoplastic polymer, and
from about 0.005% to about 0.100% by weight diamond particles having particle sizes between about 2 and about 500 nm, wherein the diamond particles are substantially uniformly distributed throughout the fiber;
incorporating the fiber into a yarn; and
preparing a fabric that comprises the yarn;
wherein incorporation of the diamond particles in the fabric produces at least a 5% increase in the thermal conductivity of the fabric in contrast to the fabric without the diamond particles.
29 . A method of increasing the strength of a fabric without a significant loss in the elongation of the fabric, comprising:
preparing a fiber having
at least 98.0% by weight thermoplastic polymer, and
from about 0.005% to about 0.100% by weight diamond particles having particle sizes between about 2 and about 500 nm, wherein the diamond particles are substantially uniformly distributed throughout the fiber;
incorporating the fiber into a yarn; and
preparing a fabric that comprises the yarn;
wherein incorporation of the diamond particles in the fabric produces a substantial increase in the strength of the fabric in contrast to the fabric without the diamond particles, without producing a substantial decrease in elongation of the fabric.