Surface-treated polymeric particles, slurry containing the same, and use thereof

Patent metadata

Field	Value
Publication number	US-2017190836-A1
Application number	US-201615394952-A
Country	US
Kind code	A1
Filing date	Dec 30, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

Surface-treated polymeric particles which are dispersible in water or an aqueous solution without the aid of any surfactant. Surface treatment of hydrophobic polymeric particles is carried out to increase the surface energy and to render the surfaces of the particles hydrophilic, thereby eliminating the need for a surfactant to disperse the polymeric particles in water or an aqueous solution. As such, a surfactantless slurry can be formed from the surface-treated particles for the fabrication of fiber-reinforced thermoplastic composite structures.

First claim

1 . Surface-treated polymeric particles, each particle comprising a core of hydrophobic thermoplastic polymer and a hydrophilic outer surface, said hydrophilic outer surface having a dispersive surface energy of less than 50 mJ/m 2 , preferably, about 30 mJ/m 2 to about 49 mJ/m 2 , as measured by Inverse Gas Chromatography (IGC),
wherein the hydrophobic thermoplastic polymer is selected from the group consisting of: polyaryletherketones (PAEKs); polyamides; poly(phenylene oxide) (PPO); polyimides; polyetherimide (PEI); polyamide-imides; polyarylsulphones; polyphenylene sulfide (PPS), polyethethylene terephthalate (PET), polyethylene terephthalate glycol (PETG); polyoxymethylene (POM); liquid crystalline polyester (LCP); polylactic acid or polylactide; poly-L-lactic acid or poly-L-lactide; polyglycolic acid; co-polymers and combinations thereof.

2 . The surface-treated polymeric particles according to claim 1 , wherein the core of each surface-treated polymeric particle constitutes at least 80% by volume of the particle.

3 . The surface-treated polymeric particles according to claim 1 , wherein the surface-treated polymeric particles have a mean particle size (d50) of about 100 μm or less, or about 1 μm to about 100 μm, as measured by laser diffraction.

4 . The surface-treated polymeric particles according to claim 1 , wherein each particle comprises a fluoro-oxidized outer surface.

5 . The surface-treated polymeric particles according to claim 1 , wherein each particle comprises a core of polyaryletherketone (PAEK) polymer or copolymer, and a hydrophilic outer surface comprising fluorine and oxygen atoms.

6 . The surface-treated particles of claim 4 , wherein the hydrophilic outer surface is obtained by exposing the particles to a gaseous atmosphere comprising oxygen and fluorine.

7 . The surface-treated polymeric particles according to claim 1 , wherein the hydrophilic outer surfaces comprise polar functional groups selected from carbonyl and hydroxyl.

8 . The surface-treated particles of claim 7 , wherein the hydrophilic outer surfaces further comprise fluorine atoms.

9 . The surface-treated particles according to claim 1 , wherein the particles have a dispersive surface energy of less than about 50 mJ/m 2 as measured by Inverse gas chromatography (IGC).

10 . The surface-treated particles according to claim 1 , wherein the surface-treated polymeric particles have a mean particle size (d50) of about 100 μm or less as measured by laser diffraction.

11 . A surfactantless slurry comprising:
the surface-treated particles according to claim 1 dispersed in an aqueous solution or in water, wherein the dispersion is void of any surfactant (or surface active agent).

12 . The surfactantless slurry of claim 11 , wherein the surface-treated particles are present in an amount of about 0.5% to about 60% by weight based on the total weight of the slurry.

13 . A method for fabricating a thermoplastic composite structure, comprising:
(a) exposing particles of hydrophobic thermoplastic polymer to a surface treatment that renders the outer surfaces of the particles hydrophilic; (b) forming an aqueous slurry comprising the surface-treated particles without adding any surfactant; (c) applying the aqueous slurry to a first layer of reinforcement fibers to distribute the particles onto the fibers, forming a first particle-coated layer; (d) placing an additional layer of reinforcement fibers on the first particle-coated layer; (e) applying the aqueous slurry to the additional layer of reinforcement fibers to distribute the particles onto the fibers, forming a subsequent particle-coated layer; (f) drying the particle-coated layers; and (g) consolidating the particle-coated layers by applying heat and pressure.

14 . The method of claim 13 further comprising:
repeating (d) and (e) to build up a composite laminate prior to drying at (f).

15 . The method according to claim 13 , wherein the reinforcement fibers are in the form of continuous unidirectionally aligned fibers, woven fabric, nonwoven fabric, or nonwoven mat of randomly arranged fibers.

16 . The method according to claim 13 , wherein the reinforcement fibers are selected from carbon fibers, aramid fibers, glass fibers, and combinations thereof.

17 . The method according to claim 13 , wherein the particles of hydrophobic thermoplastic polymer at (a) are particles of a thermoplastic material selected from: polyaryletherketones (PAEKs); polyamides, including semi-aromatic polyamide such as polypthalamide (PPA); thermoplastic poly-olefins; poly(phenylene oxide) (PPO), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), polyimides; polyetherimide (PEI); polyamide-imides; poly aryl sulones including PES, PEES; polyphenylene sulfide (PPS), polyethethylene terephthalate (PET), polyethylene terephthalate glycol (PETG); polyoxymethylene (POM); liquid crystalline polyester (LCP); polymethylmethacrylate (PMMA); polylactic acid or polylactide; poly-L-lactic acid or poly-L-lactide; polyglycolic acid; co-polymers and combinations thereof.

18 . The method according to claim 17 , wherein the particles of hydrophobic thermoplastic polymer at (a) are particles of PAEK polymer or copolymer thereof.

19 . The method according to claim 13 , wherein the surface treatment is carried out by exposing the particles to a gaseous atmosphere comprising oxygen and fluorine.

Assignees

• Cytec Ind Inc

Inventors

• Griffin James Martin
• Ho Kingsley Kin Chee
• Pratte James Francis

Classifications

• B32B2307/54

  Yield strength; Tensile strength · CPC title

• B32B2262/0253

  Polyolefin fibres · CPC title

• B32B2605/18

  Aircraft · CPC title

• B29K2071/00

  Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material · CPC title

• B32B5/06

  characterised by a fibrous {or filamentary} layer {mechanically connected, e.g. by needling} to another layer, e.g. of fibres, of paper · CPC title