Polystyrene with poly

Thermoform able sheet may be mono- or multilayer with the latter produced by lamination or coextmsion. Multilayers are employed to incorporate high oxygen-barrier materials between stmctural or high water-vapor barrier plastics. Both ethylene vinyl alcohol copolymers and poly(vinyhdene chloride) (less often) are used as high oxygen-barrier interior layers with polystyrene or polypropylene as the stmctural layers, and polyolefin on the exterior for sealing. 

The observation in 1949 (4) that isobutyl vinyl ether (IBVE) can be polymerized with stereoregularity ushered in the stereochemical study of polymers, eventually leading to the development of stereoregular polypropylene. In fact, vinyl ethers were key monomers in the early polymer Hterature. Eor example, ethyl vinyl ether (EVE) was first polymerized in the presence of iodine in 1878 and the overall polymerization was systematically studied during the 1920s (5). There has been much academic interest in living cationic polymerization of vinyl ethers and in the unusual compatibiUty of poly(MVE) with polystyrene. 

In situ preparation of polymer blends of 1,4-polybutadiene with polystyrene, or poly(l-butene) has been achieved by using the heterogeneous Ziegler-Natta type catalyst (C2H )2A1C1—Ti(OC4H )4 in the host polymers (217). Homogeneous catalysts can also be used to catalyze these reactions (218). 

The anthraquinones are useful in acrylics and are compatible with polystyrene and ceUulosics. Solvent Red 111 has a special affinity for poly(methyl methacrylate) as the red in automobile taillights exposure for a year in Florida or Arizona produces only a very slight darkening. Acid types are usehil for phenohcs (see Dyes, anthraquinone). 

The important features of rigidity and transparency make the material competitive with polystyrene, cellulose acetate and poly(methyl methacrylate) for a number of applications. In general the copolymer is cheaper than poly(methyl methacrylate) and cellulose acetate, tougher than poly(methyl methacrylate) and polystyrene and superior in chemical and most physical properties to polystyrene and cellulose acetate. It does not have such a high transparency or such food weathering properties as poly(methyl methacrylate). As a result of these considerations the styrene-acrylonitrile copolymers have found applications for dials, knobs and covers for domestic appliances, electrical equipment and car equipment, for picnic ware and housewares, and a number of other industrial and domestic applications with requirements somewhat more stringent than can be met by polystyrene. 

The GBR resin works well for nonionic and certain ionic polymers such as various native and derivatized starches, including sodium carboxymethylcel-lulose, methylcellulose, dextrans, carrageenans, hydroxypropyl methylcellu-lose, cellulose sulfate, and pullulans. GBR columns can be used in virtually any solvent or mixture of solvents from hexane to 1 M NaOH as long as they are miscible. Using sulfonated PDVB gels, mixtures of methanol and 0.1 M Na acetate will run many polar ionic-type polymers such as poly-2-acrylamido-2-methyl-l-propanesulfonic acid, polystyrene sulfonic acids, and poly aniline/ polystyrene sulfonic acid. Sulfonated columns can also be used with water glacial acetic acid mixtures, typically 90/10 (v/v). Polyacrylic acids run well on sulfonated gels in 0.2 M NaAc, pH 7.75. 

Table 5 Comparison of Properties of Lactide Polymers with Polystyrene and Poly(vinyl chloride) ...

Figure 5 Corona discharge behavior of polystyrene added with polystyrene-b-poly(sodium acrylate) [57].

Hollow and porous polymer capsules of micrometer size have been fabricated by using emulsion polymerization or through interfacial polymerization strategies [79,83-84, 88-90], Micron-size, hollow cross-linked polymer capsules were prepared by suspension polymerization of emulsion droplets with polystyrene dissolved in an aqueous solution of poly(vinyl alcohol) [88], while latex capsules with a multihollow structure were processed by seeded emulsion polymerization [89], Ceramic hollow capsules have also been prepared by emulsion/phase-separation procedures [14,91-96] For example, hollow silica capsules with diameters of 1-100 micrometers were obtained by interfacial reactions conducted in oil/water emulsions [91],... 

Figure 16 SEC molar mass distribution of poly(p-phenylene) P3 in THF after universal calibration based on Equations (31) (dashed) and (36) (dotted) and with polystyrene calibration (solid line). 

A six-armed star polymer consisting of ethane substituted with polystyrene [poly(l-phenyl-ethane-1,2-diyl)] blocks ... 

Poly(ethane-l,2-diyl/l-hydroxyethane-l,2-diyl) grafted with polystyrene [poly(l-phenylethane-l,2-diyl)] at hydroxymethylene units ... 

Poly(phenylene ether) 170 Often alloyed with polystyrene... 

Many other polymeric systems are of interest in polymer LEDs. Polythiophenes have been known for some time but it was not until improved synthetic methods were developed that their potential was realised. The process involves the reaction of the substituted monomer with FeClj in chloroform solution. After polymerisation has occurred the product precipitates and is isolated and washed. Further special purification methods are required to obtain satisfactorily pure materials. One product, of commercial interest, developed by Bayer is poly(ethylenedioxy)thiophene, known as PEDOT (3.110). This product when doped with polystyrene sulfonate, sold as Baytron P, has been found to be effective as a conducting, hole-injecting layer on the ITO electrode. ... 

Poly (methyl methacrylate) was also subjected to mechanical reaction in a vibrating mill in common solvent for several monomers (ethylene, acrylic acid and its esters, acrylonitrile and styrene) at temperatures from —196 to 20° C (22). The formation of macroradicals and their reactions were followed by EPR (electron paramagnetic resonance). The macroradicals reacted with vinyl monomers at temperatures less than —100° C, while quinones underwent reaction as low as —196° C. The same experiments were performed also with polystyrene and polybutylenedimethacrylate. The radicals from polystyrene were more reactive than those from poly(methyl methacrylate). 

Figure 4 shows the modulus curves for two blends of PEO E4000 (75 and 50%) with poly-4-vinylbiphenyl and one blend of 50% PEO E4000 with polystyrene. None of these blends exhibited a well, and at high temperatures the samples became friable and broke. 

The calibration was established with polystyrene standards supplied by Waters Associates. The broad-distribution poly (vinyl chloride) standards were obtained from Arro Laboratories, Joliet, 111. Other PVC samples studied were obtained from Shawinigan Chemicals Division, Gulf Oil of Canada Ltd. For all GPC analyses, small sample loads (ca 4 mg) and slow rates ca 0.76 ml/min) were used to maximize resolution. 

C6Hj-N = N-C(C6H5)2(OCOCH3) b By membrane osmometry, PM AN = poly(methacrylonitrile) c By GPC, calibrated with polystyrene standards d Grafting efficiency (see Sect. 3.2.7)... 

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