Poly(ether ketone ketone) (PEKK) composites
AssigneesSolvay Specialty Polymers USA, LLC, Cytec Industries Inc.
InventorsChantal Louis, James Pratte, Craig Swanson
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Abstract
Poly(ether ketone ketone) (PEKK) composites include reinforcing fibers in a PEKK polymer matrix that includes a PEKK polymer. It was surprisingly discovered that by washing unneutralized PEKK polymer powder with an acid or base, the melt stability of the PEKK polymers can be improved, as compared with PEKK polymers prepared by conventional methods. The PEKK composites are especially well-suited for fabrication of thick composite parts where melt stability is especially important.
Claims12
A method of increasing the melt stability of an unneutralized poly(ether ketone ketone) (PEKK) polymer powder comprising:
- washing the unneutralized poly(ether ketone ketone) (PEKK) polymer powder with a solution including an acid or base to form a neutralized PEKK polymer,
- wherein the unneutralized PEKK polymer has a residual acidity of greater than 10 μeq/g or a residual basicity greater than −24 μeq/g;
- and
- wherein,
- the acid is selected from the group consisting of acetic acid, mono alkali metal citrates, alkali or alkaline earth metal dihydrogenphosphates, and combinations thereof,
- the base is selected from the group consisting of organic amines, tetraalkylammonium hydroxides, tetraalkylammonium acetates, tetraalkylphosphonium hydroxides, tetraalkylphosphonium acetates, alkali or alkaline earth metal hydroxides, alkali or alkaline earth metal monohydrogenphosphates, alkali or alkaline earth metal phosphates, and combinations thereof;
- and
- if the residual acidity is greater than 10 μeq/g, the solution includes the base and the washing reduces the residual acidity of the unneutralized PEKK polymer to less than or equal to 10 μeq/g;
- if the residual basicity is greater than −24 μeq/g, the solution includes the acid and the washing reduces the residual basicity of the unneutralized PEKK polymer to less than or equal to −24 μeq/g.
A composite comprising reinforcing fibers in a polymer matrix,
- wherein the polymer matrix comprises a poly(ether ketone ketone) (PEKK) including at least one recurring unit (RMPEKK) and at least one recurring unit (RPPEKK),
- wherein:
- each recurring unit (RMPEKK) is represented by formula:
- -[-Mm-O—]-, (1), and
- each recurring unit (RMPEKK) is represented by formula:
- -[-Mp-O—]-, (2)
- wherein:
- Mm and Mp are represented by the following formulae, respectively:
- and
- and
- wherein:
- each R1 and R2, at each instance, is independently selected from the group consisting of an alkyl, an alkenyl, an alkynyl, an aryl, an ether, a thioether, a carboxylic acid, an ester, an amide, an imide, an alkali or alkaline earth metal sulfonate, an alkyl sulfonate, an alkali or alkaline earth metal phosphonate, an alkyl phosphonate, an amine, and a quaternary ammonium;
- and
- each i and j, at each instance, is an independently selected integers ranging from 0 to 4;
- further wherein:
- the poly(ether ketone ketone) (PEKK) includes greater than 30 wt·ppm of aluminum and greater than 200 wt·ppm of phosphorus as determined by ICP-OES, and
- the poly(ether ketone ketone) (PEKK) has a thermal stability (Td 2%) of at least 495° C. as measured by thermal gravimetric analysis according to ASTM D3850 from 30° C. to 800° C. under nitrogen (60 mL/min) at 10° C./minute.
Dependencies are inferred from the claim text.