Acrylic acid polymerization fiber

Itaconic acid is a specialty monomer that affords performance advantages to certain polymeric coatings (qv) (see Polyesters, unsaturated). Emulsion stabihty, flow properties of the formulated coating, and adhesion to substrates are improved by the acid. Acrylonitrile fibers with low levels of the acid comonomer exhibit improved dye receptivity which allows mote efficient dyeing to deeper shades (see Acrylonitrile polymers Fibers, acrylic) (10,11). Itaconic acid has also been incorporated in PAN precursors of carbon and graphite fibers (qv) and into ethylene ionomers (qv) (12). 

The polycomplexes obtained by template polymerization of methacrylic acid or acrylic acid in the presence of poly(N,N,N, N - tetramethyl-N-p-xylene-ethylenediammonium dichloride) were used for spinning of fine fibers 5 to 50 pm in diameter. The fibers are soluble in water but become stable after thermal treatment at about 80°C. The polycomplex with regular structure, obtained by template polymerization, is expected to be of considerable interest for textile industry. 

On the other hand, chemicals might be chosen as agents for generation of active centers in the polymeric backbone and grafting of monomer in the vapor phase. Ammonium persulfate and styrene (189), acrylic acid (190), butyl acrylate (191), potassium persulfate and n-butyl maleate or 2-ethyl hexyl acrylate (55,134) and ammonium ceric nitrate and methacrylic add (192) are examples of this method. Benzoyl peroxide deposited on polycaprolactam fibers initiates the grafting of styrene in vapor phase (193). 

Acrylic acid is almost exclusively used directly, or after conversion to an ester, as a monomer. Acrylate esters are produced by normal esterification processes. However, in dealing with acrylic acid, acrolein, or acrylates, unusual care must be taken to minimize losses due to polymerization and other side reactions such as additions of water, acids, or alcohols across the reactive double bond. Polyacrylic acids find use in superabsorbers, dispersants, and water treatment. The polyesters are used in surface coatings, textile fibers, adhesives, and various other applications. 

Acrylamide with a demand of 200,000 tons year" is one of the most important commodities in the world. It is used for the preparation of coagulators, soil conditioners, stock additives for paper treatment, and in leather and textile industry as a component of synthetic fibers. Conventional chemical synthesis involving hydration of acrylonitrile with the use of copper salts as a catalyst has some disadvantages rate of acrylic acid formation higher than acrylamide, by-products formation and polymerization, and high-energy inputs. To overcome these limits since 1985, the Japanese company Nitto Chemical Industry developed a biocatalyzed process to synthesize... 

Of a large number of possible fluorinated acrylates, the homopolymers and copolymers of fluoroalkyl acrylates and methacrylates are the most suitable for practical applications. They are used in the manufacture of plastic lightguides (optical fibers) resists water-, oil-, and dirt-repellent coatings and other advanced applications [14]. Several rather complex methods to prepare the a-fluoroalkyl monomers (e.g., a-phenyl fluoroacrylates, a-(trifluoromethyl) acrylic and its esters, esters of perfluoromethacrylic acid) exist and are discussed in some detail in [14]. Generally, a-fluoroacrylates polymerize more readily than corresponding nonfluorinated acrylates and methacrylates, mostly by free radical mechanism [15], Copolymerization of fluoroacrylates has been carried out in bulk, solution, or emulsion initiated with peroxides, azobisisobutyronitrile, or y-irradiation [16]. Fluoroalkyl methacrylates and acrylates also polymerize by anionic mechanism, but the polymerization rates are considerably slower than those of radical polymerization [17]. 

Ethylene has been separated from ethane by a silver nitrate solution passing countercurrent in a hollow fiber poly-sulfone.165 This separation has also been performed with the silver nitrate solution between two sheets of a polysilox-ane.166 A hydrated silver ion-exchanged Nafion film separated 1,5-hexadiene from 1-hexene with separation factors of 50-80.167 Polyethylene, graft-polymerized with acrylic acid, then converted to its silver salt, favored isobutylene over isobutane by a factor of 10. Olefins, such as ethylene, can be separated from paraffins by electroinduced facilitated transport using a Nafion membrane containing copper ions and platinum.168 A carbon molecular sieve made by pyrolysis of a polyimide, followed by enlargement of the pores with water at 400 C selected propylene over propane with an a-valve greater than 100 at 35°C.169... 

Into a pressure pol5nnerization vessel are added 150 gm water, 3 gm ammonium persulfate, and 24 gm (0.415 mole) allyl alcohol. The mixture is cooled to 15°C and then 50 gm (0.695 mole) of acrylic acid is added. The mixture is further cooled to - 20°C and 26 gm (0.406 mole) of sulfuric dioxide is added. The vessel is sealed and polymerization is initiated by raising the temperature to 40°C with initial agitation. Polymerization is continued for 16 hr and then the reaction mixture is cooled, water added, and the mixture steam distilled at 200 mm pressure. The steam distillation is continued until 100 gm water is collected. The polymer is soluble in hot water and when the solution is cooled no polymer settles. The solution has little odor and can be used to cast clear film on glass plates, or used as spinning dope to prepare fibers which are insolubi-lized by heat. The polymer analyzes as follows 27% sulfur dioxide, 50% acrylic acid, and 23% allyl alcohol. 

Acrylic acid esters Free-radical-initiated chain polymerization Fiber modification, coatings, adhesives, paints... 

Name given to plastics produced by the polymerization of acrylic acid derivatives, usually including methyl methacrylate. An amorphous thermoplastic material. In technological jargon polymethylmethacrylate (PMMA) or polyacrylonitrile fiber with at least 85 wt% of PAN. A mechanical reducing mechanism between the barrel and either a nozzle or a die. 

Moreover, long(>200 cm) fibers 1 mm in diameter were formed from thermoplastic gels ofY-123 ceramics and PVA." Calcined fibers exhibited values of = 92-94K. These fibers form materials characterized by different values, depending on the degree of saponification (DS) and the Y-123 ceramic content of these materi-als." The minimum critical current density occures when DS = 67 mol%, and the maximum value (J = 3.5 X 10 Acm, 77K) when DS = 81 mol%. The critical current density is also affected by the conditions of treatment (calcination and pyrolysis), which is associated with the peculiarities of the distribution of the ceramics over the fibers. High-T). superconductor nanocomposites have also been prepared by polymerization of acrylic acid in an aqueous solution of Y + nitrate and Ba + and Cu " acetates. " ... 

The nonwoven polyolefin fabric is used. The thickness of the separator is 100-200 pm, and the basis weight of the fiber is 50-80 g/m. The hydrophilicity is provided to the fiber surface of the separator with the sulfonation treatment, plasma treatment or acrylic acid graft polymerization treatment. 

Two proaches have been reported to immobilize enzyme on ultra-fine cellulose fibers, i.e., adsorption and covalent binding. Both approaches improved the protein binding ability of fiber surfaces by adding chemical functionalities via covalently bonded polymeric chains to ultra-fine cellulose fiber surfaces. Adsorption of enzyme proteins on fiber surfaces was accomplished by ceric ion-initiated graft polymerization of electrolyte acrylic acid monomer and the subsequent enzyme adsorption via secondary forces. 

Unsaturated polyester-acrylic acid mixtures have been polymerized in situ on polyester fibers to provide graft polymer sizes that are easily removed by neutralization with a base. This type of combination has also been claimed for producing photopolymerized printing plates.These two patents give examples of how unsaturated polyesters may be mixed and polymerized with unconventional reactive diluent monomers to meet new special needs. 

---