Methyl methacrylate polyester fibers

A review covers the preparation and properties of both MABS and MBS polymers (75). Literature is available on the grafting of methacrylates onto a wide variety of other substrates (76,77). Typical examples include the grafting of methyl methacrylate onto mbbers by a variety of methods chemical (78,79), photochemical (80), radiation (80,81), and mastication (82). Methyl methacrylate has been grafted onto such substrates as cellulose (83), poly(vinyl alcohol) (84), polyester fibers (85), polyethylene (86), poly(styrene) (87), poly(vinyl chloride) (88), and other alkyl methacrylates (89). 

Smaller volumes of methanol are used in the production of dimethyl terephthalate that goes into polyester fibers and in methyl methacrylate, which goes into plastics. 

Methyl methacrylate, accounting for 4% of methanol consumption, is produced by the cyanohydrin process utilizing methanol. Methyl methacrylate is used to produce acrylic sheet, surface coating resin, and molding and extrusion powder. Also, there exist minor miscellaneous uses such as modification of acrylic fiber and polyester resin. 

Ogiwara, Kubota, and Yasunaga (23) have examined the effect of fiber swelling, photosensitizer, and solvent on photo-induced graft polymerization of methyl methacrylate on vinyl, nylon 6, and polyester fibers. Solvent-induced swelling of fiber as well as the presence of certain sensitizers were found to increase photo-induced grafting through enhancement of radical formation on the fibers. 

Linear Polymers Long chains are necessary to confer the mechanical properties of fibers, plastics, and elastomers that make polymers so valuable. Fibers such as cellulose and polyester arc semicrystalline materials in which the same chemical stmeture exists in both rigid microcrystalline and flexible amorphous phases. Plastics may be either semicrystalline, such as poly(ethylene terephthalate) (the same polyester of fibers is also the PET of beverage bottles), or completely amorphous and glassy, such as polystyrene or poly(methyl methacrylate) (PMMA, Plexiglas or Lucite ). Elastomers are completely amorphous and flexible and would flow as a viscous mbbery liquid except that the polymer chains are cross-hnked to prevent macroscopic flow but allow reversible stretching. As an example, poly(dimethylsiloxane)... 

In general, rigid plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. Examples of materials, which will respond satisfactorily in the range of 10 and 10 erg per gram, are fluoroplastics, glass fiber-filled phenolics, certain epoxies, polyurethane, polystyrene, mineral-filled polyesters, silicone, and fiirane resins. The next group of resins in order of radiation resistance includes polyethylene, melamine, urea formaldehyde resins, unfilled phenolic, and silicone resins. Those materials, which have poor radiation resistance, include methyl methacrylate, imfilled polyesters, cellulosics, polyamides, and fluorocarbons (Tables 9.16 and 9.17). 

Polyester fibers are composed of linear chains of polyethylene terephthalate (PET), which produces benzene, benzoic acid, biphenyl, and vinyl terephthalate on pyrolysis. Acrylic fibers comprise chains made up of acrylonitrile units, usually copolymerized with less than 15% by weight of other monomers, e.g., methyl acrylate, methyl methacrylate, or vinylpyrrolidone. Thermolysis results in the formation of acrylonitrile monomer, dimers, and trimers with a small amount of the copolymer or its pyrolysis product. In this case, the acrylic is Orion 28, which contains methyl vinyl pyridine as comonomer. Residual dimethyl formamide solvent from the manufacturing process is also found in the pyrolysis products. Cotton, which is almost pure cellulose, comprises chains of glucose units. The pyrolysis products of cellulose, identified by GC/MS, include carbonyl compounds, acids, methyl esters, furans, pyrans, anhydrosugars, and hydrocarbons. The major pyrolysis products are levoglucosan (1,6-anhydro-B-D-glucopyranose) and substituted furans. 

Acrylic polyesters are also used by the polymer industry to produce fibers. However, the blends and composites of this class of polymers with conductive polymers were systematically prepared in the form of films One of the first attempts involved the electrochemical polymerization of 3-methylthiophene using an electrolyte solution containing poly(methyl methacrylate) [92]. By this method poly(methyl methacrylate) is codeposited on the electrode with the conductive polymer, forming a self-supported film. The conductivity of the film on the electrode side was two orders of magnitude higher than on the electrolyte side. Cyclic voltammetry and the visible spectra of the blend reproduce exactly the curves for the pure conductive polymer. This one-step synthesis is an alternative to the electrode coating method, provided that the insulating polymer host is soluble in the electrolyte solution. 

Tables 10 and 11 show pultruded materials with glass fiber and carbon fiber respectively. For both tables the following abbreviations have been used PP-polypropylene, PMMA-poly (methyl methacrylate), PU-polyurediane, NY6-nylon 6, PPS-polyphenylene sulfide, UP-unsaturated polyester, PH-phenolic resin and ABS-acrylobutadiene styrene.

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