Coatings from polybutadienes

Figure 3.17 contains the difference spectrum between ATH and ATH which had been coated, from solution, with the same grade of MPBD. In this spectrum relatively weak adsorptions at 1860 cm and 1781 cm are present indicating some unreacted MPBD, but in addition a strong peak at 1700 cm exists which corresponds to the absorption frequency of the carbonyl stretch in the carboxylic acid. Clear evidence that the anhydride has hydrolysed, but the lack of a strong peak at 1580 cm, the carbonyl stretching frequency of the salt, shows that the acid had not reacted with the surface of the ATH to form salt bridging between the polybutadiene backbone and the filler surface. 

Fitzpatrick et al. [41] used small-spot XPS to determine the failure mechanism of adhesively bonded, phosphated hot-dipped galvanized steel (HDGS) upon exposure to a humid environment. Substrates were prepared by applying a phosphate conversion coating and then a chromate rinse to HDGS. Lap joints were prepared from substrates having dimensions of 110 x 20 x 1.2 mm using a polybutadiene (PBD) adhesive with a bond line thickness of 250 p,m. The Joints were exposed to 95% RH at 35 C for 12 months and then pulled to failure. 

Figure 4 a and b. Normalized FTIR-RA spectra of polybutadiene coating on cold-rolled steel exposed to 40 °C and 80% RH for different times. Reproduced with permission from reference 3. 

Coating with Bulk Polybutadiene. E-glass fabric was embedded In Firestone s Diene 35 NFA using procedures very similar to those used to prepare peel test specimens. Rubber, which had been mill-mixed with 0.05% dlcumyl peroxide, was premolded between Mylar sheets to the desired thlckness(0.308, 0.151, or 0.100 cm) and size ( 30.5 X 18 cm) by molding for 1 hour at 60 C. and 40,000 lbs/5" ram. Fabric was cut so that the final size was at least one Inch smaller than the rubber sheets In all directions. A sandwich was made from the fabric and two premolded rubber sheets of the same thickness and about half the total thickness of the final sandwich. The sandwich was cured In a press for 2 hours at 150°C and 5000 lbs/5" ram. In the cured specimen the fabric was embedded In the center of the molded specimen (0.15 -0.40 In thick). Samples were Immensed In alkali before cutting to size for tensile tests. 

Some technological information on the Aerojet General Corporation s composite propellants technology was published recently [20]. Ammonium perchlorate is ground to the particle sizes ranging from 1 to 200 fx and then mixed to form a blend of the various particle sizes which gives the best mechanical and ballistic properties. Ammonium perchlorate is mixed with liquid polybutadiene-acrylonitrile fuel, liquid plasticizer and aluminium powder (Fig. 118). The motor casing is coated internally... 

Figure 4.5 Normalized attenuation-vs-veiocity changes for a polymer-coated SAW device as vapor partial pressures are varied from 0% (at dashed line) to 80% of saturation. The polymer, Kraton D1102, is an ABA triblock copolymer, where A is polystyrene (approximately 28% by weight) and B is polybutadiene. (Reprinted with permission. See Ref. (621.)...

Carr and others have described the preparation and properties of polybutadiene (PBD) and polyethyleneimine (PEI), as well as aromatic polymer-coated and carbon-clad zirconia-based RP phases. The preparation of PBD-coated zirconia and the chromatographic evaluation of these phases have been described extensively by Carr, McNeff, and others [39 1]. From these studies, the authors conclude that at least for neutral analytes PBD zirconia-coated phases behave quite similar with respect to retention and efficiency compared to silica-based RP phases [42]. For polar and ionic analytes, however, substantial differences with respect to retention, selectivity, and efficiency have been reported [43]. 

In Fig. 11.7 the distribution of drugs belonging to several pharmacological clas.ses on the plane determined by the first two principal components account together for 81.5% of the variability in the retention data measured from 8 HPLC systems I50. The HPLC systems comprised stationary phases such as standard and specially deactivated hydrocarbonaceous silicas, polybutadiene-coated alumina, immobilized artificial membrane and immobilized Oi-acid glycoprotein. Methanol-buffer eluents of varying compositions and pH were used. The clustering of analytes is consistent with their estab-... 

Blends, e.g. 80 20, of poly (methyl methacrylate) (PMMA, weight average molar mass, Mw, of 15,000 g/mol) and polybutadiene (PB, with Mw 420,000 g/mol) (e.g. from Aldrich) are prepared by mixing solutions of a mass fraction of PMMA of 0.02 in toluene and mass fraction of PB of 0.02 in toluene in a ratio of 8 2 followed by spin-coating onto pre-cleaned silicon wafers. Following the spinning, the samples are treated for 24 h at ambient temperatures under vacuum to remove residual solvent. Pieces of the blend-covered silicon wafer are glued to the sample holder disc and inserted into the AFM. 

Fig. 1.8 Fe2p3/2 spectrum acquired at the interface between an iron substrate and a polybutadiene coating. The Fe(ll) components result from the reduction of the iron oxide by the polymer.

Alumina is as mechanically stable as silica, but is hydrolytically more stable, especially in the alkaline pH range. Therefore it is attractive as a carrier for reversed-phase surfaces. However, no surface-derivatization technique comparable to the silanization of silica is available. Coating techniques have been developed by Schomburg et al. (27), which add a stable hydrophobic polymer to the alumina surface. The most popular packing type, which is available from several sources, is alumina coated with a crosslinked polybutadiene. The second commercially available type is obtained by applying a polysiloxane coating to the alumina. 

Polybutadiene polymers that have a 1,2 microstructure varying from 60 to 90% offer potential as moldings, laminating resins, coatings, and cast liquid and formed sheet products. Outstanding electrical and thermal stability results from the structure that is essentially prue hydrocarbon. 

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