Color polymer synthesis

In another research laboratory, surprised by the lack of success of other research groups and the previous statements about the impossibility of applying biocatalytic chemistry to polithiophenes and polypyrroles, special attention was paid to the enzymatic polymerization of the EDOT monomer [43]. In this case, the first trials succeeded and a blue-colored polymer solution was obtained after 16h of reaction (Scheme 4). As is well-known, an acidic reaction medium is suitable to increase the rate of polymerization. Protonic acids and a variety of Lewis acids catalyze the equilibrium reaction of EDOT to the corresponding dimeric and trimeric compounds without further oxidation or reaction [44]. In this work, three different pHs were evaluated (pH = 2, 4, and 6) in order to establish the optimum for adequate synthesis of EDOT. The UV-visible (UV-Vis) spectra for these three reactions are... 

Self-doped PANI are very interesting due to their unique electrochemical behavior unlike PANI, the self-doped polymer remains in its doped state in near neutral or alkaline media [28]. Fully self-doped PANIs are not easy to synthesize due to the lower reactivity of acid-functionalized anilines. Kim et al. [29, 30] introduced an alternative approach in the template-assisted enzymatic polymerization of aniline. Previously, only polyanionic templates had been used for PANI synthesis. However, acid-functionalized anilines bear a net anionic charge in aqueous solution, and attempts to use SPS as template with carboxyl-functionalized aniline resulted in red-brown colored polymers with no polaron transitions, regardless of the synthetic conditions. The use of polycationic templates, such as those shown in Figure 8.2 allowed the synthesis of linear and electrically conductive PANIs with self-doping ability due to the doping effect of the carboxyl groups present in the polymer backbone. 

Preparation of the resin Polystyrene-divinylbenzene (1%) copolymer 21 (Fluka) was washed [71] to removed shorter polystyrene components and remaining monomers and reagents with each of the following solutions at 60-80°C for 30-60 min NaOH (1 N), HCl (1 N), NaOH (2 N)-dioxane (1 2), HCl (2 N)-dioxane (1 20, water, dimethyl formamide (DMF). The resin was then washed at room temperature with HCl (2 N) in methanol, water, methanol, methanol-dichloromethane (1 3), and methanol-dichlo-romethane (1 10) and the resin was dried at 50-70°C under reduced pressure. The washed polystyrene resin (13 g) was suspended under nitrogen in anhydrous cyclohexane (80 mL) in a 250-mL polymer synthesis flask. Tetra-methylethylenediamine (TMEDA, 20 mL, 132.5 mmol) and n-butyllithium (2.0 M in cyclohexane, 80 mL, 160 mmol) were successively added and the mixture was stirred at 65°C for 4 h. The dark burgundy-colored resin was filtered under nitrogen and washed with anhydrous cyclohexane (2 X 100... 

Hossain MD, Sato T, Higuchi M (2013) Green color copper-based metallo-supramolecular polymer synthesis, structure, and electrochromic properties. Chem Asian J 8 76-79. doi 10.1002/asia.201200668... 

Practical methods for synthesis and elucidation of the optimum physical forms were developed at Du Pont (13). The violets fill the void in the color gamut when the inorganics are inadequate. The quinacridones may be used in most resins except polymers such as nylon-6,6, polystyrene, and ABS. They are stable up to 275°C and show excellent weatherabiUty. One use is to shade phthalocyanines to match Indanthrone Blue. In carpeting, the quinacridones are recommended for polypropylene, acrylonitrile, polyester, and nylon-6 filaments. Predispersions in plastici2ers ate used in thermoset polyesters, urethanes, and epoxy resins (14). 

The partially aromatic PAs are exclusively made of die diamine-diacid type and not die amine-acid type. The aromatic diamines, similar to phenylene diamines, color easily and dieir polymers are conjugated, having a golden brown color. The aromatic diacids used in the formation of partially aromatic PAs are mainly terephthalic and isophthalic acids. Starting with the diacids, the PA salt is made first and with this the salt prepolymers are prepared. The prepolymerization is usually carried out in an autoclave to prevent die sublimation of the reactants. In a laboratory synthesis it would be preferable to avoid this autoclave step as one is not always available. It is possible to start with the more reactive esters, such as diphenyl isophtiialate, or with the acid chlorides starting with the reactive isocyanates is, in principle, also possible. The terephthalic and isophthalic acids are also used to modify PA-6,6 and PA-4,6 to more dimensionally stable copolymers.6,18... 

Liquid Crystal Displays (LCD). Liquid crystal displays, once limited to small devices such as calculators, are now displacing color CRT (cathode ray tube) displays in commercial quantities. The ability to fabricate these display devices at high quality and at low cost is partially due to the wider spread use of photopolymer-based materials. Photopolymer technology is being used for the alignment of liquid crystal (LC) elements (49), the orientation of ferroelectric materials (50), the synthesis of LC polymers (57) and the manufacture of color filters for liquid crystal display applications (52). 

K.Y. Musick, Q.-S. Hu, and L. Pu, Synthesis of binaphthyl-oligothiophene copolymers with emissions of different colors systematically tuning the photoluminescence of conjugated polymers, Macromolecules, 31 2933-2942, 1998. 

A regularity in the melting points was observed for the members of both series. The synthesis of 2-thienylpolyene aldehydes was attempted. Polymers were obtained, which possessed the color of the expected aldehydes, the color being a function of the number of conjugated double bonds. 

A modular and flexible approach to polythiophene sensors based on the polymerization of a thiophene-activated ester has been reported (Bernier et al. 2002). Subsequent reaction of the pol5mierized NHS ester with a variety of diamines permits the synthesis of sensors for different analytes from a common platform. For example, reaction of the NHS polymer with an aminomethyl-modified 15-crown-5 derivative yielded a polymer that underwent color changes in the presence of alkah cations (Fig. 12.14). 

Aqueous systems have been used in separations, coatings, and synthesis. Aqueous biphasic systems have been developed for hquid-liquid extractions using water-soluble polymers such as polyethylene glycol, and inorganic salts such as ammonium chloride or potassium phosphate (Rogers et al., 1998), (Sherman et al., 1998). These systems have been investigated for use in the separation and recovery of heavy metals from mixed wastes and in the recovery of colored impurities from textile waste streams (Sherman et al., 1998). 

Attention was then turned to aromatic heterocyclic ladder polymers other than BBL. Due to the complexities in their synthesis, ladder polymers were not reported extensively in the literature at that time. A sample of polyfluoflavine (I) having an inherent viscosity in methanesulfonic acid of 2.5 was obtained from professor C. S. Marvel at the University of Arizona. The ladder polymer was prepared [5] from the A-B polycondensation of 2,3-dihydroxy-6,7-diamino-quinoxaline hydrochloride in PPA. Transparent blue sheets were observed on precipitation of this polymer from methanesulfonic acid, and when collected and dried, it formed gold films much like the color of the BBL films. It was felt at that time that all ladder polymers of sufficient molecular weight would form precipitated films. 

---