AQUEOUS POLYMERIC DISPERSIONS, METHODS OF MAKING THE SAME AND SIZED FIBER TOWS
Various embodiments disclosed relate to an aqueous dispersion. The aqueous dispersion includes a plurality of particles. Each of the particles includes a polycarbonate component. Individual particles of the polycarbonate component have substantially the same size. The dispersion further includes a plasticizer component and a surfactant component. In an embodiment, a sized carbon fiber tow can comprise: a polycarbonate sizing on a carbon fiber tow, wherein the polycarbonate sizing has a concentration of volatile organic compounds less than 10 ppm, preferably less than 5 ppm, or less than 2 ppm; and an average sizing content of at least 0.5 wt % of the carbon fiber tow with a coefficient of variation less than 15%, preferably less than 11%.
1 . An aqueous dispersion comprising:
a plurality of particles each particle comprising a polycarbonate component, wherein individual particles have a value of the particle diameter at 90% of the cumulative distribution of particles as determined by analyses of a dynamic light scattering plot (D 90 ) in a range of 300 nm to 4,000 nm and wherein the polycarbonate component comprises at least one of a linear homopolycarbonate of a bisphenol, a branched, cyanophenol end-capped homopolycarbonate, a copolycarbonate comprising bisphenol A carbonate units and bisphenol carbonate units comprising 12 to 60 carbon atoms, a poly(aromatic ester-carbonate), poly(carbonate-siloxane), a poly(ester-siloxane-carbonate), and a poly(aliphatic ester-carbonate);
a plasticizer component; and
a surfactant component,
wherein polycarbonate means a polymer or copolymer having repeating structural carbonate units of Formula (I):
wherein at least 60 percent of the total number of R 1 groups are aromatic, or each R 1 contains at least one C6-30 aromatic group.
2 . The aqueous dispersion of claim 1 , wherein the particles are present in an amount of 50 wt % to 90 wt % of the aqueous dispersion, preferably wherein the aqueous dispersion comprises from 1 wt % to 20 wt % plasticizer component, preferably wherein the aqueous dispersion comprises from 1 wt % to 30 wt % surfactant component, and wherein the total weight percentage in the aqueous dispersion is 100 wt %.
3 . The aqueous dispersion of claim 1 , wherein the individual particles have a D 90 in a range of 300 nm to 4000 nm, preferably in a range of 300 nm to 600 nm, or in a range of 300 nm to 400 nm, preferably the particles have a D 98 of 340 nm to 345 nm.
4 . The aqueous dispersion of claim 1 , wherein the aqueous dispersion is substantially free of phase separation between the plurality of particles and the surfactant component for a time period of greater than 1 month, preferably greater than 12 months.
5 . The aqueous dispersion of claim 1 , wherein a plasticizer of the plasticizer component is resorcinol diphenyl phosphate.
6 . The aqueous dispersion of claim 1 , wherein the surfactant component is an anionic surfactant.
7 . The aqueous dispersion of claim 1 , wherein the plurality of particles has a monomodal size distribution.
8 . An article produced from the aqueous dispersion of claim 1 .
9 . The article of claim 8 , wherein the article is a powder, a film, a sizing, a coating, a tie layer, an adhesive, a composite unidirectional tape, a three-dimensional printed article, or an article of woven fiber.
10 . A method of forming the aqueous dispersion of claim 1 , the method comprising:
combining an organic phase and an aqueous phase to form a first solution, the organic phase comprising a polycarbonate component and a solvent component, the aqueous phase comprising water and a surfactant component;
heating the first solution to evaporate the solvent component; and form a second solution; and
combining a plasticizer component with the second solution to form the aqueous dispersion.
11 . The method of claim 10 , further comprising mixing at least one of the first solution or the second solution, wherein the mixing is performed under shear at 7,000 to 30,000 rpm
12 . The method of claim 10 , wherein heating the first solution comprises heating the first solution to a temperature at or above the boiling point of the solvent component and below the boiling point of the water.
13 . A sized carbon fiber tow, comprising:
a polycarbonate sizing on a carbon fiber tow, wherein polycarbonate means a polymer or copolymer having repeating structural carbonate units of Formula (I):
wherein at least 60 percent of the total number of R 1 groups are aromatic, or each R 1 contains at least one C6-30 aromatic group, and wherein the polycarbonate sizing has a concentration of volatile organic compounds less than 10 ppm, preferably less than 5 ppm, or less than 2 ppm; and
an average sizing content of at least 0.5 wt % of the carbon fiber tow with a coefficient of variation less than 15%, preferably less than 11% wherein the average sizing content is an average of sizing content measured according to ASTM D2584 various points across a predetermined length of the carbon fiber tow, and sizing content is ((w 1 −w 0 )/w 0 )×100, wherein, w 1 =weight of sized carbon fiber tow; w 0 =weight of carbon fiber tow (unsized) and wherein coefficient of variation is 100 times standard deviation, S, divided by the average sizing content, where S=[Σ(x i −x a ) 2 /(n−1)] 1/2 .
14 . The sized carbon fiber tow of claim 13 , wherein the average sizing content ranges from 0.9 wt % to 2.4 wt % of the carbon fiber tow.
15 . The sized carbon fiber tow of claim 13 , wherein the volatile organic compounds are members selected from the group consisting of methylene chloride, perchloro-ethylene, methyl-tertiary butyl ether (MTBE), N-Methyl-2-pyrrolidone, t-butyl acetate, dimethylformamide (DMF), dioxane, dichloromethane (DCM), n-alkane (C12-C18), dimethyl carbonate, cyclopentanone, chloroform, formaldehydes, acetone, toluene, xylene, benzene, hexane, diphenyl carbonate, or combinations thereof.
16 . The sized carbon fiber tow of claim 13 , wherein the polycarbonate sizing is formed from the aqueous dispersion of claim 1 .
17 . A method of preparing the sized carbon fiber tow of claim 13 , comprising:
spreading the carbon fiber tow over a spreader unit at a throughput line speed of at least 0.3 meters/minute and forming spread carbon fibers;
sizing the spread carbon fibers in a sizing bath containing an aqueous polycarbonate sizing dispersion and forming sized carbon fibers; and
drying the sized carbon fibers to obtain the sized carbon fiber tow.
18 . The method of claim 17 , wherein the sized carbon fibers are dried in an oven operating at a temperature ranging from 150° C. to 300° C.
19 . The method according to claim 17 , wherein the aqueous polycarbonate sizing dispersion has a minimum film formation temperature (MFFT) according to ASTM D2354 ranging from 100° C. to 180° C.