Solvent dispersion thermoplastic polymers

Many studies have used these methods for processing of both thermosetting and thermoplastic polymers. Y. Liao (53) dissolved epoxy in a well-dispersed, ultra-sonicated CNT suspension. The solvent was evaporated, and the epoxy was subsequently cured to form a nanocomposite in which the good CNT dispersion was achieved. Jin et al. (54) produced various types of polymer-coated and polymer-grafted MWNT solutions, in some cases evaporating the solvent and subsequently melt-mixing with another polymer. Yudasaka et al. (55) used a mixture of SWNTs and PMMA in monochlorobenzene (MCB) for dispersion, purification and subsequent spin-casting of the material. 

Very few CPs are produced in bulk quantities. Polyphenylene sulfide, a member of the third generation of polymers, was produced in bulk quantities many years before CPs were established and its dopability was elucidated. Polyethylenedioxythiophene is commercially available as a water-based colloidal dispersion (Baytron P water dispersion), and presumably as dispersible powders. The powders with a conductivity of 5-10 S/cm can be dispersed in thermoplastic polymers and in organic solvents such as xylene. Polyaniline doped with dodecylbenzene sulfonic acid and complexed with zinc dodecylbenzene sulfonate is commercially available as a powder, which can be dispersed in polyolefins. The same polymer doped with p-toluenesulfonic acid is also available as a dispersible powder, Ormecon, and in a predispersed form for solution processing in polar and nonpolar media. Based on Ormecon PANi, there are many commercial products marketed for many different applications. 

Dispersions using PAni in binderless solvents today display a particle size of 10 nm. Thermoplastic polymers or paints contain (secondary) agglomerates with a size of about 100 nm. 

To aid dispersion of the carbon fiber in the polymer matrix, it is usual to apply a polymer compatible size, normally a lower molecular weight version of the polymer can be used, preferably in a water base (e.g. a polyurethane). If the fiber has an epoxy size, this must be removed by solvent extraction in a solvent degreasing plant. Under some conditions, it is possible to blend 10% epoxy sized fiber. If the thermoplastic polymer is to be used at high temperatures (e.g. PEEK), then the size must be temperature resistant, such as a polyimide. 

Chen Lu Guang, and Shanks Robert. Thermoplastic polymer-dispersed liquid crystals prepared from solvent induced phase separation with predictions using solubility parameters. Liq. Cryst. 34 no. 12 (2007) 1349-1356. 

Liquid crystal and polymer dispersions are fabricated using thermally-induced phase separation (TIPS), solvent-induced phase separation (SIPS), or Polymerization-induced phase separation (PIPSX/I)- For TIPS, a homogeneous mixture of a low-molecular weight liquid crystal and thermoplastic polymer is cooled below the critical phase separation temperature to induce phase separation into liquid crystal rich and polymer rich domains. The morphological properties (domain size, number of domains per unit volume, and the composition of the domains) depend primarily on the choice of liquid crystal and thermoplastic polymer, the initial weight fraction of liquid crystal in die initial mixture, and the rate of cooling. 

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