Chemical synthesis cellulose acetate

Table 9.2 summarizes the uses of acetic acid. Vinyl acetate is another top 50 chemical. Acetic anhydride is used to make cellulose acetate and at times has been in the top 50 chemicals itself. Cellulose acetate is a polymer used mainly as a fiber in clothing and cigarette filters. Ethyl acetate is a common organic solvent. Acetic acid is used as a solvent in the manufacture of terephthalic acid (TA) and dimethyl terephthalate (DMT), which are monomers for the synthesis of poly(ethylene terephthalate), the polyester of the textile industry. A minor household use of acetic acid is as a 3-5% aqueous solution, which is called vinegar. 

Eastman Chemical Company, together with Halcon, developed a commercial acetic anhydride process to an industrial scale [41b, 47]. This process starts with coal to make a hydrogen-rich synthesis gas, which is purified (Figure 4). A portion of the syn gas is separated to produce methanol from 2 1 H2/CO. Part of the methanol is used to scrub H2S from the coal-gasification step. The remainder of the methanol is combined with acetic acid to make methyl acetate. The methyl acetate is carbonylated to give acetic anhydride. The acetic anhydride is used to produce cellulose acetate in another process, and the resulting acetic acid is recycled to the esterification section. The acetic anhydride step of the pro-... 

Acetone is used as a solvent for cellulose acetate, nitrocellulose and acetylene as a raw material for the chemical synthesis of such products as ketones, acetic anhydride, methyl methacrylate, bisphenol-A, diacetone alcohol, methyl isobutyl ketone, isophorone, etc. 

The growth of synthetic fibers has led to the devising of syntheses from petroleum of the chemical intermediates required for this new industry. Leaving aside acetic anhydride from ethylene via synthetic ethanol and from propylene via acetone, already established and used for cellulose acetate in the 193O s, nylon has called for the isolation of petroleum cyclohexane and for the discovery of a route from butadiene to nylon salt Dacron for the isolation of p-xylene from petroleum xylene, and the nitrile fibers for the synthesis of acrylonitrile from ethylene or acetylene. 

Acetic anhydride is used in the manufacture of cellulose acetate-based film, cigarette filters, and plastics. Eastman Chemical developed a process that is based on gasification of coal in a Texaco gasifier to make synthesis gas which then is converted to methanol. The methanol is converted to methyl acetate by esterification with acetic acid and then carbonylated. The carbonylation process uses rhodium salt catalysts with ligands and an iodine promoter [30]. 

Acetic acid occurs in vinegar. It is produced in the destructive distillation of wood. It finds extensive application in the chemical industry. It is used in the manufacture of cellulose acetate, acetate rayon, and various acetate and acetyl compounds as a solvent for gums, oils, and resins as a food preservative in printing and dyeing and in organic synthesis. 

Nitromethane is active chemically, can have many chemical reactions as a chemical reagent or synthesis intermediate. It also can be used as solvents for cellulose nitrate, cellulose acetate, cellulose acetate, vinyl resin, polyacrylate coating, beeswax, etc. base or other materials can be added into nitromethane for generate explosives when nitromethane is mixed with strong oxidant hydrogen peroxide or N2O4, it can be used as liquid rocket propellants and fuel nitromethane can also be used in medicine, dyes, insecticides, fungicides, stabilizers and surfactants. 

Dlamylamine is a colorless to straw-colored liquid with an ommaniacal odor, which is composed of a mixture of amyl isomers. It is soluble in ethyl alcohol, methyl alcohol, ethyl ethers, ethyl acetate, acetone, aromatic and aliphatic hydrocarbons, fixed oils, mineral oil, oleic and stearic acids. It is insoluble in water and while soluble in hot paraffin and carnauba waxes, these solidify an coaling. It is a solvent for ails, resins, and some cellulose esters. Introduction of the amyl group imparts oil solubility to otherwise oil-insoluble substances. It is used as a corrosion inhibitor, and in chemical synthesis. 

Uses Solvent for cellulose acetate, roll-coating inks, paints, lacquers, stains intermediate for organic synthesis, pharmaceuticals, photographic chemicals in electroplating fragrance in cosmetics... 

Cellulose acetate butyrate Glass lonomer resin Phenoxy resin Polycarbonate Polyethylene, low-density Polyvinyl chloride Vinylidene chloride monomer piping, chemical Chlorotrifluoroethylene polymer piping, chemical processing Polyvinylidene chloride piping/equip., chemical-resistant Polyvinylidene fluoride resin piracetam synthesis... 

The aliphatic carboxylic acids are valuable intermediates in the synthesis of other organic chemicals, resins and polymer compositions. The reaction of a carboxylic acid with an aliphatic alcohol in the presence of an acidic catalyst yields a valuable series of aliphatic ester solvents. The cellulose acetate and... 

Although the cellulose feedstock for cellulose acetate synthesis is certainly a green material, acetic anhydride used to make the acetate is a corrosive, toxic chemical that produces poorly healing wounds on exposed flesh. Furthermore, potentially hazardous solvents, such as dichlorometh-ane, are used in some processes for making cellulose acetate. 

Various methods have been used for the synthesis and smdies of the chemical and physical properties of the polymeric membrane reactor with embedded nanoparticles. These methods include sonochemical, ultraviolet (UV), and y irradiation, and chemical reduction by reducing agents such as borohydrides and hydrazine. Studies have revealed the successful synthesis of cellulose acetate thin film with embedded bimetallic nanopaiticles such as Ni/Fe, Pd/Co, and monometallic Pd for the catalytic dechlorination and hydrogenation processes (Liu et al., 1997 Liu et al., 2000 Meyer et al., 2004). Catalytically active... 

Introduction of these photocrosslinkable structures in macro-molecular chains can be performed by esterification of hydroxyla-ted polymers with cinnamoyl chloride. Cellulose Q).condensation products (4, ) and mainly poly(vinyl alcohol) have Been treated( by this method. Other chemical modifications have been studied as ester interchange of poly(vinyl acetate) 7) and Knoevenagel reaction on polyesters (8). Very few results on the synthesis of such photocrosslinkable polymers by polymerization have been reported. Therefore free radical polymerization of cinnamic acid vinyl derivatives did not lead to the expected polymers, but to insolubilization reactions. Howewer cationic procedure can be a good way in some cases since Kato et al. could polymerize by this way with high yields p-vinyl phenylcinnamate (9) and B-vinyloxyethyl cinnamate (10). 

There are many examples of the application of CD or RD for esterification.f" Esterification of methanol or ethanol with acetic acid forms methyl acetate or ethyl acetate, respectively. Methyl acetate is important in the manufacture of polyesters and is an important solvent for cellulose while ethyl acetate is used in inks, fragrances, and pharmaceuticals. The manufacture of high-purity methyl acetate is difficult because of the equilibrium limitation and also the formation of azeotropes. The production of methyl acetate by Eastman Chemical Co. was the first commercial application of RD using a homogeneous liquid acid catalyst. Only one RD column and two smaller columns for processing sidestreams are required while in the conventional methyl acetate synthesis, two reactors and eight distillation columns are required. 

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