VINYL PHENOL COPOLYMER

FIGURE 7-47 H NMR spectra of (A) a styrene-co-r-BSOS copolymer and (B) the corresponding styrene-co-vinyl phenol copolymer after deprotection. 

A final example of the application of 13C NMR spectroscopy is taken from our work9 on copolymers of methacrylates and vinyl phenol which were synthesized using similar chemistry to that shown previously for the styrene-co-vinyl phenol copolymers. In Figure 7-48 are typical 13C NMR spectra of an ethyl methacrylate (EMA) copolymer containing 52 mole % EMA before (top) and after (bottom) deprotection. The absence of the NMR peaks at around 0 ppm (the two methyl carbons attached to silicon), 19 ppm (the tertiary carbon of the f-butyl group), and 26 ppm (the three methyl carbons on the f-butyl group) after desilylation, clearly indicates the absence of any residual f-butyldi-methylsilyl groups. 

COPO blends with styrene/vinyl phenol copolymers - miscible... 

S-4VPh PVEE Poly(vinyl ethyl ether) miscibility noted with styrene-4-vinyl phenol copolymers 770... 

Covalent polymeric networks which are completely disordered. Continuity of structure is provided by an irregular three-dimensional network of covalent links, some of which are crosslinks. The network is uninterrupted and has an infinite molecular weight. Examples are vulcanized rubbers, condensation polymers, vinyl-divinyl copolymers, alkyd and phenolic resins. 

Figure 1. Preparation of the copolymers of 4-vinylbenzyl acetate and 4-vinyl-phenol.

Systems in which a polyolefin is the binder have attracted world-wide attention. These include the polyethylene—phenolic microsphere 74,115>, polyethylene or polypropylene—glass microsphere114116), polyethylene or polybutylene—PVC microsphere (containing isobutane)52), and polyethylene/vinyl acetate copolymer—glass microsphere11 systems. Syntactic foams have been made from polystyrene (and its copolymers with chlorostyrene or polychlorostyrene) and microspheres made from polyethylene or polypropylene46115 and foams from styrene/acrylonitrile 1171... 

A new approach was proposed for making effective helmets which could replace the former British army steel helmet. Essentially the new helmet used modified phenolic resins reinforced with nylon, and the crown cap inside was thermoformed from polyethylene. Formerly the crown cap was attached to the steel by rivets—not an appropriate method for fixing polyethylene to reinforced plastics. Instead a method was developed with a hot-melt adhesive based on ethylene-vinyl acetate copolymers cast as film on release paper. For assembly, the cast film is cut in advance to match the intricate shape required and activated by heat to bond under light pressure subsequently, a further heat activation is employed to fix the crown cap in place (Figure 52 illustrates this). 

Poly(vinyl alcohol) is utilized as a component of starch-based adhesives.11121114 Other patents report the use of partially oxidized starch,1115 dextrins,1116 dextrins and urea,1117 borax,1118 boric acid,1119 and vinyl methyl ether-maleic acid copolymers.1120 Other patents indicate the use of poly (vinyl alcohol) with partially hydrolyzed poly(vinyl acetate),1121 nonhy-drolyzed poly(vinyl acetate),1122 and poly(vinyl chloride).1123 A few patents have reported such poly acrylic additives as poly (acrylic acid)1124 and its salts,1125 poly(acrylamide),1126 1127 A-methylacrylamide or poly(A-acryl-amide),1128 and polyethyleneimine.1129 Polystyrene has also been used,1130 as well as more complex copolymers such as a maleic acid monobutyl ester-methyl vinyl ether copolymer, together with dextrin and polyacrylamide),1131 carboxylated ethyl acrylate-styrene zinc salt copolymer,1132 ethylene-methyl acrylate-vinyl acetate copolymer,1133 vinyl acetate-vinyl pyr-rolidone copolymer,1134 and ethylene-vinyl acetate copolymer.1135 Some adhesives are compounded with SBR latex1136 1138 and phenol-formaldehyde resins.1139... 

Synthetic polymers in general can be classified (1) by thermal behavior, i.e., thermoplastic and thermosetting (2) by chemical nature, i.e., amino, alkyd, acrylic, vinyl, phenolic, cellulosic, epoxy, urethane, siloxane, etc. and (3) by molecular structure, i.e., atactic, stereospecific, linear, cross-linked, block, graft, ladder, etc. Copolymers are products made by combining two or more polymers in one reaction (styrene-butadiene). See cross-linking block polymer epitaxy homopolymer plastics. 

The most widely used thermoplastic polymer is the ethylene—vinyl acetate copolymer, which is obtainable in a wide range of molecular weights as well as in a variety of compositions. Often flexibilizers or plasticizers are added in order to improve both the mechanical shock resistance and the thermal properties of the adhesive. Polybutenes, phthalates, and tricresyl phosphate have been used as plasticizers. Tackifying agents can also be added. Because hot-melt adhesives are frequendy ethylene-based, they are subject to oxidation if, as in a typical situation, the adhesive sits in an applicator for long periods before use. Thus, antioxidants such as hindered phenols are often used, as are fillers. Fillers are added to opacify or to modify the adhesive s flow characteristics, as well as to reduce cost. Wax is also a very important component. Wax alters surface characteristics by decreasing both the liquid adhesive s surface tension and its viscosity in the melt. Upon solidification, however, the wax acts to increase the strength of the adhesive. Both paraffin and microcrystalline wax are used (see Waxes). 

Copolymers with styrene and alkyl methacrylates were synthesized also. The coupling method was initially developed by Asami et al. (200. 210) who succeeded in preparing polymerizable oligomers from living poly(THF) by coupling with vinyl phenolate (CH2=CH-C H -0 ) or with vinylbenzyl alcoholate (CH2=CH-C H -CH20 ). The horaopolymerization and copolymerization of these Macroraers were studied (209). 

The coreaction of phenolic resins with alkyds is an "old timer" in which the excellent gloss retention and durability of alkyds are combined with the water and alkali resistance of phenolics. Alkyd resin can be designed to have compatibility with hydroxyl-modified vinyl chloride-vinyl acetate copolymer resins, and this combination of fast drying, adhesion, excellent water resistance, and durability is specified in a number of coatings for military and marine use. 

To address these shortcomings the carboxylic acid was replaced with weaker phenol for a better shelf life and dry etch stability and the vinyl ether functionality was separated from the acidic functionality employing a three component design. A water soluble phenolic copolymer was prepared by radical copolymerization of 4-acetoxystyrene and sodium styrenesulfonate, followed by deacetylation with ammonium hydroxide. A water soluble bis(vinyl ether)... 

Binders are macromolecular products with a molecular mass between 500 and ca. 30000. The higher molecular mass products include cellulose nitrate and polyacrylate and vinyl chloride copolymers, which are suitable for physical film formation. The low molecular mass products include alkyd resins, phenolic resins, polyisocyanates, and epoxy resins. To produce acceptable films, these binders must be chemically hardened after application to the substrate to produce high molecular mass cross-linked macromolecules. 

Toluene [108-88-3] is mainly used in cellulose nitrate lacquers in heat-curing paints based on urea-, melamine-, or phenol - formaldehyde resins in alkyd resin paints and in paints based on chlorinated rubber, polystyrene, polyacrylates, or poly(vinyl acetate). Mixtures of toluene with esters are used to dissolve vinyl chloride copolymers and postchlorinated poly(vinyl chloride) [14.265]. 

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