Nanotube Polymer Composite Composition and Methods of Making
Embodiments of the invention include compositions comprising a polymer an amount of nanotubes extrusion compounded together. The amount of the nanotubes dispersed in the polymer forms a composition with a storage modulus G′ that does not increase further extrusion compounding of the composition. Extrusion compounded compositions of conductive nanotubes and polymer can be molded into electrically dissipative articles whose resistivity decreases with decreasing shear flow in the molding process.
1 . A composition comprising:
a polymer melt and an amount of single walled carbon nanotubes extrusion compounded together in the composition, the amount of said nanotubes dispersed in the polymer, said composition has a storage modulus G′ that is substantially invariant with further extrusion compounding of the composition.
2 . The composition of claim 1 wherein said polymer is a high temperature, high strength thermoplastic polymer.
3 . The composition of claim 1 wherein a storage modulus at low frequency of the composition is at least about 90 times a storage modulus at low frequency of the polymer when the amount of single walled nanotubes distributed in the composition is 0.5% wt.
4 . The composition of claim 1 wherein an increase in molding shear flow rate or strain of the composition increases the electrical resistivity of an article molded by said composition.
5 . An article comprising a molded composition of claim 1 wherein said molded composition is electrically dissipative.
6 . An article comprising a molded composition of claim 1 wherein said molded composition is flame retardant.
7 . The composition of claim 1 wherein the polymer melt comprises PEEK, PI, or PEI
8 . The composition of claim 1 wherein the polymer melt comprises PEEK or PEI.
9 . An article comprising a molded composition of claim 1 wherein said molded composition is electrically insulating and wherein said molded composition becomes electrically dissipative with heating.
10 . The composition of claim 1 wherein the amount of single walled carbon nanotubes is less than 10% by weight.
11 . The composition of claim 1 wherein the amount of single walled carbon nanotubes is 7% by weight or less.
12 . The composition of claim 1 wherein an axial force measured in a squeeze flow test of said composition is greater than an axial force measured on a second extrusion compounded polymer composition comprising the nanotubes distributed into an extruded melt of the polymer, said nanotubes added into to the extruded melt of the polymer at a location equal to or greater than half the length of an extruder used to make the composition of claim 1 and the second composition.
13 . A composition comprising:
a polymer melt and an amount of single walled carbon nanotubes extrusion compounded together in the composition, the amount of said nanotubes distributed and or dispersed in the polymer melt forms an electrically dissipative solid in a low shear flow molding process, the electrical resistivity of an article molded from said composition increases with increasing molding shear flow rate.
14 . The composition of claim 13 wherein said polymer is a high temperature, high strength thermoplastic polymer.
15 . The composition of claim 13 wherein a storage modulus at low frequency of a non-solid sample of the composition is at least about 90 times a storage modulus at low frequency of a non-solid sample of the polymer when the amount of single walled nanotubes distributed in the composition is 0.5% wt.
16 . An article comprising the composition of claim 13 molded in a low shear flow rate process.
17 . The article of claim 16 wherein the resistivity can be increased by extensional flow.
18 . An article comprising a molded composition of claim 13 wherein said molded composition is flame retardant.
19 . The composition of claim 13 wherein the polymer melt comprises PEEK, PI, or PEI.
20 . The composition of claim 13 wherein the polymer melt comprises PEEK or PEI.
21 . An article comprising a molded composition of claim 13 wherein said molded composition is electrically insulating and wherein said molded composition becomes electrically dissipative with heating.
22 . The composition of claim 13 wherein the amount of single walled carbon nanotubes is less than about 10% by weight.
23 . The composition of claim 13 wherein the amount of single walled carbon nanotubes is about 7% by weight or less.
24 . An article comprising:
a composition of a polymer that is a continuous phase and an amount of single walled carbon nanotubes dispersed in the polymer, wherein a storage modulus at low frequency on a non-solid sample of the article is at least about 90 times a storage modulus at low frequency of a non-solid sample of the polymer when the amount of single walled nanotubes dispersed in the composition is 0.5% wt.
25 . The article of claim 24 where the article is electrically dissipative.
26 . The article of claim 24 wherein an electrical resistivity of the article is reduced by extensional flow.
27 . The article of claim 24 where the article is flame retardant.
28 . The article of claim 24 where the article is flame retardant and electrically dissipative.
29 . The article of claim 24 wherein the polymer comprises PEEK, PI, or PEI
30 . The article of claim 24 wherein the polymer melt comprises PEEK or PEI.
31 . The article of claim 24 where the article is electrically insulating and wherein said the article becomes electrically dissipative with heating.
32 . The article of claim 24 wherein the amount of single walled carbon nanotubes is less than about 10% by weight.
33 . The article of claim 24 wherein the amount of single walled carbon nanotubes is 7% by weight or less.
34 . The article of claim 24 that has an surface resistivity of less than about 10 9 ohms/sq.
35 . The composition of claim 24 that has an surface resistivity of less than about 10 7 ohms/sq.
36 . The composition of claim 24 that has an surface resistivity of less than about 10 4 ohms/sq.
37 . A composition comprising:
a thermoplastic polymer; and
a network of single walled carbon nanotubes dispersed in said thermoplastic polymer, a melt of said composition has a storage modulus proportional to frequency according to G′=Kω z where K is a proportionality constant, ω is the frequency between 0.01 and 1 rad/sec, and z is less than 1.7; and
wherein an amount of said single walled carbon nanotube in said composition is greater than 0.5 wt %, said storage modulus at a fixed frequency decreases with further extrusion compounding of the composition.
38 . The composition of claim 37 wherein the metal extractables of said composition is less than 200 microgram/gram of iron as determined by acid digestion of said composition.
39 . The composition of claim 37 wherein said single walled carbon nanotubes are single walled carbon nanotubes having an aspect ratio of 100 or more.
40 . The composition of claim 37 wherein said composition outgasses organics less than 0.01 microgram/gram.
41 . The composition of claim 37 where said single walled carbon nanotubes are not polymer wrapped single walled carbon nanotubes.
42 . The composition of claim 37 having a surface resistivity less than 10 9 ohms/sq.
43 . The composition of claim 37 wherein the amount of single walled carbon nanotubes is between 0.5 wt % and 10 wt %.
44 . The composition of claim 37 wherein the network is characterized by a storage modulus that is at least 90 times greater than the storage modulus of the polymer at a frequency of 1 rad/sec or less when the amount of single walled carbon nanotubes is between 2 and 7 wt %.
45 . The composition of claim 37 wherein the composition does not comprise added carbon powders.
46 . The composition of claim 37 wherein the volume resistivity or surface resistivity of said composition can be decreased with heat treatment.
47 . A fluid handling article comprising the composition of claim 37 .
48 . A carrier comprising the composition of claim 37 .
49 . A housing comprising the composition of claim 37 .
50 . The composition of claim 37 wherein the network is characterized by a storage modulus that is at least 150 times greater than the storage modulus of the polymer at a frequency of 0.1 rad/sec when the amount of single walled carbon nanotubes is greater than 2 wt %.