Thermoplastic compositions including blends of polyether ether ketone and polyetherimide
Thermoplastic compositions include: from about 50 wt % to about 70 wt % of a PEEK (polyether ether ketone) component; from about 5 wt % to about 20 wt % of a PEI (polyetherimide) component; and from about 20 wt % to about 40 wt % of a glass fiber component. The combined weight percent value of all components does not exceed 100 wt %, and all weight percent values are based on the total weight of the composition. Methods for forming a molded article including the thermoplastic composition are described.
1 . A thermoplastic composition consisting of:
from about 50 wt % to about 70 wt % of a PEEK (polyether ether ketone) homopolymer;
from about 5 wt % to about 20 wt % of a PEI (polyetherimide) homopolymer; and
from about 20 wt % to about 40 wt % glass fiber,
wherein a rectangular sample of the composition injection molded into a mold having a length of 8 in (inches), a width of 6 in, and a thickness of 3.2 mm (millimeters) exhibits a shrinkage of less than 0.5% in length and less than 0.5% in width at 23° C., and
wherein the combined weight percent value of all components does not exceed 100 wt %, and all weight percent values are based on the total weight of the composition.
2 . The thermoplastic composition according to claim 1 , wherein the composition consists of from about 55 wt % to about 65 wt % of the PEEK homopolymer, from about 5 wt % to about 15 wt % of the PEI homopolymer, and from about 25 wt % to about 35 wt % of the glass fiber.
3 . The thermoplastic composition according to claim 1 , wherein the composition consists of from about 58 wt % to about 60 wt % of the PEEK homopolymer, about 10 wt % of the PEI homopolymer, and from about 30 wt % to about 32 wt % of the glass fiber.
4 . The thermoplastic composition according claim 1 , wherein the glass fiber consists of chopped glass fiber, flat glass fiber, or a combination thereof.
5 . The thermoplastic composition according to claim 4 , wherein the glass fiber consists of glass fibers having a length of about 3 mm (millimeters).
6 . The thermoplastic composition according to claim 1 , wherein the PEEK homopolymer has a melt viscosity of from 120 to 180 Pascal-seconds (Pa-s) at 400° C. as determined in accordance with ISO 11443.
7 . The thermoplastic composition according to claim 1 , wherein the rectangular sample exhibits a shrinkage of less than 0.45% in length and less than 0.45% in width.
8 . The thermoplastic composition according to claim 1 , wherein the rectangular sample exhibits a shrinkage of about 0.35% in length and about 0.4% in width.
9 . The thermoplastic composition according to claim 1 , wherein the rectangular sample exhibits a total warpage of less than 1.0 mm, wherein total warpage is determined by measuring warpage at each of 4 corners of the rectangular sample and adding the warpage at the 4 corners to determine total warpage.
10 . The thermoplastic composition according to claim 1 , wherein the rectangular sample exhibits at least 50% less total warpage than a comparative sample that does not include the PEI homopolymer, wherein total warpage is determined by measuring warpage at each of 4 corners of the rectangular sample and adding the warpage at the 4 corners to determine total warpage.
11 . A method for forming a molded article, consisting of:
combining, to form a mixture, (a) from about 50 wt % to about 70 wt % of a PEEK (polyether ether ketone) homopolymer, (b) from about 5 wt % to about 20 wt % of a PEI (polyetherimide) homopolymer, and (c) from about 20 wt % to about 40 wt % glass fiber; and
molding the mixture to form the molded article,
wherein a rectangular molded sample of the mixture that is injection molded into a mold having a length of 8 in (inches), a width of 6 in, and a thickness of 3.2 mm (millimeters) exhibits a shrinkage of less than 0.5% in length and less than 0.5% in width at 23° C., and
wherein the combined weight percent value of all components does not exceed 100 wt %, and all weight percent values are based on the total weight of the article.
12 . The method according to claim 11 , wherein the molding consists of injection molding, extrusion, rotational molding, blow molding, thermoforming, or a combination thereof.
13 . The method according to claim 11 , wherein the article consists of from about 55 wt % to about 65 wt % of the PEEK homopolymer, from about 5 wt % to about 15 wt % of the PEI homopolymer, and from about 25 wt % to about 35 wt % of the glass fiber.
14 . An article consisting of the thermoplastic composition according to claim 1 , wherein the article is a compressor plate, a housing for a telecommunications device, or a bracket for an automotive sensor.