Study of Polymers

The XPS study of ion-beam irradiation effects in polyamide layers have been studied by Karpuzov et al. (1989). Thin polyamide films deposited on silicon or metal covered glass-ceramic substrates were exposed to ion bombardment at different fluences ranging from 1 x 10 to 1.5x 10 cm. The XPS technique was used to study the polymer stoichiometry of the near surface layers ( 75 A) before and after the bombardment. The results show that the stoichiometric ratio of O, N, and C-groups remains approximately constant with depth for unirradiated samples. 

The work by Pireaux et al. (1995) on the so-called reactive (pol3detra-fluoroethylene) and even more stable (polypropylene and polyethylene) polymers based on the use of XPS valence band spectra, showed that irradiation can lead to superficial structural modification - lateral chain grafting, or cross-linking. This structural modification appears more pronounced for high fluence UV excimer laser irradiation in air, than for (more moderate) exposition to harder X-rays in vacuum. 

XPS was used for determination of metal-polymer interaction and chemical state of atoms on metal-polymer interface after diffusion of Ag and Cu atoms in polyethyleneterephtalate (PET) and polyamide (PI) by Mackova et al. (2005). XPS measurement gives an evidence of Ag clustering in Ag-PET samples prepared by cathode sputtering. In PI the Cu atoms exhibit higher diffusivity than Ag atoms due to their lower atomic radius. 

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Schneider J, Erdelen C, Ringsdorf H and Rabolt J F 1989 Structural studies of polymers with hydrophilic spacer groups. 2. Infrared-spectroscopy of Langmuir-Blodgett multilayers of polymers with fluorocarbon side-chains at ambient and elevated temperatures Macromolecules 22 3475-80... 

Thus the study of polymers containing thiazole rings, linked by alkyl or... 

More recently, Raman spectroscopy has been used to investigate the vibrational spectroscopy of polymer Hquid crystals (46) (see Liquid crystalline materials), the kinetics of polymerization (47) (see Kinetic measurements), synthetic polymers and mbbers (48), and stress and strain in fibers and composites (49) (see Composite materials). The relationship between Raman spectra and the stmcture of conjugated and conducting polymers has been reviewed (50,51). In addition, a general review of ft-Raman studies of polymers has been pubUshed (52). 

The Flory-Huggins Interaction Parameter. These ideas, based on a study of polymer miscibility, have been appHed to plasticizers according to the foUowiag equation ia which is the molar volume of the plasticizer, obtaiaed from molar mass figures and density values at T, and represents the iateraction parameter (11). 

Unlike shear viscosity, extensional viscosity has no meaning unless the type of deformation is specified. The three types of extensional viscosity identified and measured are uniaxial or simple, biaxial, and pure shear. Uniaxial viscosity is the only one used to characterize fluids. It has been employed mainly in the study of polymer melts, but also for other fluids. For a Newtonian fluid, the uniaxial extensional viscosity is three times the shear viscosity ... 

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. 

Many other surfaces can be investigated by HREELS. As larger molecule and non-single-ciystal examples, we briefly describe the use of HREELS in studies of polymer surfaces. The usefiilness of HREELS specifically in polymer surface science... 

Other SSIMS studies of polymer surfaces have included perfluorinated polyether [3.21], low-density polyethylene [3.22], poly(ethylene terephthalate) [3.23], and the oxidation of polyetheretherketone [3.24]. 

After 1930, when the true nature of polymers was at last generally, recognised, the study of polymers expanded from being the province of organic specialists physical chemists like Paul Flory and physicists like Charles Frank became involved. In this short chapter, I shall be especially concerned to map this broadening range of research on polymers. 

D. Y. Yoon, M. Vacatello, G. D. Smith. Simulation studies of polymer melts at interfaces. In K. Binder, ed. Monte Carlo and Molecular Dynamics Simulations in Polymer Science. New York Oxford University Press, 1995, pp. 422-A15. 

D. Wu, K. Hui, D. Chandler. Monte Carlo study of polymers in equilibrium with random obstacles. J Chem Phys 96.-835-841, 1991. 

Singhal J.S. T ien, Flammability Study of Polymer Fuels Using Opposed-Jet Diffusion Flame Technique, Rept No SQUID-TR-CWRU-3-PU, Contract N00014-67-A-0226-0005, Purdue Univ, Lafayette (1975)... 

In a number of experimental studies of polymer diffusion, molar mass exponents close to 2 have been found, though always with some deviations. For example, using radio-labelled molecules, the diffusion coefficient of polystyrene in dibutyl phthalate was found to follow the relationship... 

This second group of tests is designed to measure the mechanical response of a substance to applied vibrational loads or strains. Both temperature and frequency can be varied, and thus contribute to the information that these tests can provide. There are a number of such tests, of which the major ones are probably the torsion pendulum and dynamic mechanical thermal analysis (DMTA). The underlying principles of these dynamic tests have been covered earlier. Such tests are used as relatively rapid methods of characterisation and evaluation of viscoelastic polymers, including the measurement of T, the study of the curing characteristics of thermosets, and the study of polymer blends and their compatibility. They can be used in essentially non-destructive modes and, unlike the majority of measurements made in non-dynamic tests, they yield data on continuous properties of polymeric materials, rather than discontinuous ones, as are any of the types of strength which are measured routinely. 

Report 125 Structural Studies of Polymers by Solution NMR, H.N. Cheng, Hercules Incorporated. 

For NMR studies of polymer mixtures, the earliest approach proposed was the Coleman-Fox model.(5) This model assumes the coexistence of two interconverting Bemoullian propagating sites and was used extensively for poly(methyl methacrylate).(6-8)... 

Reiter, J., Zifferer, G. and Olaj, O. F. (1989) Monte-Carlo studies of polymer-chain dimensions in the melt in 2 dimensions. Macromolecules, 22, 3120-3124. 

H. Dakhlia. A simulation study of polymer flooding and surfactant flooding using horizontal wells. PhD thesis, Texas Univ, Austin, 1995. 

Chen Z, Shen YR, Somoijai GA. 2002. Studies of polymer surfaces by sum frequency generation vibrational spectroscopy. Annu Rev Phys Chem 53 437-465. 

Ogasawara, Ma Application of Pulse Radiolysis to the Study of Polymers and Polymerizations. VoLlQ5,pp. 37-80,... 

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