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  • 11
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 933-939 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Spinning speed is one of the most important process parameters for change in properties of yarn and efficiency of polyester production. In this paper the effect of spinning speed (3000-6200 ypm) on dynamic mechanical properties is presented, and shows a good qualitative picture on the influence of structure change on the dynamic modulus and the height and position of glass transition peak on POY (partially oriented polyester) and PTY (draw-textured polyester) yarns. The dynamic moduli of POY yarns in a temperature range of 25-160°C are increased with increasing spinning speed. Large glass transition peaks (α peak) are observed for POY yarn spun at 3000 and 2800 ypm at about 98°C. This indicates that the yarns are low oriented with low crystallinity (5-6%). But the Tg of POY spun at 5600 or 6200 ypm is about 125°C and shows about 35% crystallinity with high amorphous orientation. An approximately linear relation was found between the height of the loss peak (tan δ) and the degree of amorphous orientation (fa) by using these analyses.
    Additional Material: 6 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 111-125 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have prepared a number of high molecular weight, soluble, symmetrical dialkyl substituted germanium homopolymers and germanium-silicon copolymers. In solution, the absorption of the homopolymers was ∼ 20 nm red shifted from the crossponding silicon derivatives. This was somewhat unexpected based on theoretical predictions and has been rationalized on the basis of conformational arguments. In the solid state, samples of poly(di-n-hexylgermane) and poly(di-n-octylgermane) are strongly thermochromic. The effect is attributed to the conformational locking of the backbone which is caused by the crystallization of the side groups. In this regard, the germanium derivatives behave similarly to the corresponding silicon polymers, and the convergence of the long wavelength absorptions for both types of polymers is consistent with theoretical predictions. The germanium-silicon copolymers are also strongly thermochromic, but the long wavelength absorption is somewhat blue shifted (8 nm) from the respective homopolymers. As expected, the new germanium homo and copolymers are quite sensitive to light and readily undergo chain scission to produce lower molecular weight materials.
    Additional Material: 5 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 813-824 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Wurtz-type coupling of a number of representative classes of substituted dichlorosilane monomers was investigated in considerable detail. Low temperature polymerization techniques, including ultrasonic activation, were also studied. Similarly, the effect of dipolar additives on the polymerization process was examined. The conclusions drawn from these studies provide some insight into the selection of useful polymerization conditions for the conversion of various monomer types into linear high polymers.
    Additional Material: 5 Tab.
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  • 14
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 2665-2677 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode.
    Additional Material: 5 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 1397-1411 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode.
    Additional Material: 5 Ill.
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  • 16
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 25 (1987), S. 321-326 
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 4 (1994), S. 95-127 
    ISSN: 1057-9257
    Keywords: Resists ; Silicon-containing ; Single layer ; Multilayer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Silicon-containing bilayer and trilayer photoresist technology is reviewed. Multilayer resist processes of this type rely on pattern generation in a thin imaging layer followed by pattern transfer to the thick planarising underlayer by oxygen reactive ion etching (RIE). The review concentrates on materials in which the silicon is an integral part of the polymer and does not specifically address photoresists where silicon is incorporated in a post-imaging process step (Such as top-surface-imaging resists). The review is not exhaustive but emphasizes instead specific examples of representative resist chemistry.
    Additional Material: 5 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 34 (1996), S. 2335-2349 
    ISSN: 0887-6266
    Keywords: morphology ; polysilanes ; thin film ; chain orientation ; spectroscopy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of confinement on the crystallinity and chain orientation of ultrathin poly(di-n-hexylsilane) films has been investigated using UV absorption, fluorescence and IR spectroscopies. UV absorption measurements in a series of poly(di-n-hexylsilane) films having thicknesses between 50 and 3500 Å have shown that, for thicknesses less than 500 Å, the polymer backbone disorders and extensive crystallization of the films is hindered irrespective of molecular weight or surface hydrophobicity. Fluorescence studies showed that rapid energy transfer occurs from the disordered chain segments to the crystalline ones. The orientation of both the polymer backbone and side chains was probed with IR absorption and grazing incidence reflection measurements. The side chains are extended, although not completely in the all-trans conformation, with their carbon plane mostly perpendicular to the substrate. The backbone lies extended, with the polymer axis parallel to the plane of the film. The hexyl side-chains disorder in films less than 2000 Å thick and this disordering occurs through the introduction of gauche bonds. Our findings suggest the possibility of using thickness to control the chain organization and morphology of a polymer thin film. © 1996 John Wiley & Sons, Inc.
    Additional Material: 15 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 2795-2802 
    ISSN: 0887-6266
    Keywords: ultrathin polymer films ; fluorescence nonradiative energy transfer ; second harmonic generation ; polymer relaxation ; small-molecule diffusion ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two optically based, molecular probe techniques are employed to study relaxation and small-molecule translational diffusion in thin and ultrathin (thicknesses 〈 ∼200 nm) polymer films. Second harmonic generation (SHG) is used to study the reorientational dynamics of a nonlinear optical chromophore, Disperse Red 1 (DR1) (previously shown to be an effective probe of α-relaxation dynamics) either covalently attached or freely doped in polymer films. Our studies on films ranging in thickness from 7 nm to 1 μm show little change in Tg with film thickness; however, a substantial broadening of the relaxation distribution is observed as film thickness decreases below approximately 150 nm. Experimental guidelines are given for using fluorescence nonradiative energy transfer (NRET) to study translational diffusion in ultrathin polymer films. Appropriate choice of a fluorescence donor species is important along with ensuring that diffusion is slow enough to be measured appropriately. Initial results on the diffusion of a small-molecule probe, lophine, in poly(isobutyl methacrylate) indicates that there is little change in probe diffusion coefficients in films as thin as 90 nm as compared to bulk films. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2795-2802, 1997
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  • 20
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 41 (1998), S. 237-243 
    ISSN: 0021-9304
    Keywords: solubility parameters ; dentin ; adhesives ; interpenetrating polymer networks ; bioadhesives ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The principal aim of this study was to investigate the relationships between the solubility parameters of etched dentin, and adhesive primer solutions and adhesive bond strength. Solubility parameters characterize the molecular interactions which determine physical properties such as wetting, and thus can serve as tools to aid development of polymeric adhesives and interpenetrating polymer networks. If an adhesive monomer has a solubility parameter close to that of a polymer substrate, then the monomer may act as a solvent for the polymer and penetrate below the surface. Subsequent polymerization of the monomer may then produce an interpenetrating network, thus adhering without necessarily forming primary chemical bonds to the substrate. The dentin substrate considered in this study was abraded dentin treated with ethylenediaminetetraacetic acid. Solubility parameters δp, δh, and δd calculated for the etched dentin substrate were 20.3, 23.6, and 16.0 (J/cm3)1/2, respectively. Solubility parameters of the primers were expressed using Hansen's three-dimensional scheme. The data indicate a correlation between the calculated solubility parameters of the etched dentin, and dentin primers and the resulting bond strengths. The results corroborate the significance of solubility parameter considerations for adhesive bonding to dentin. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 41, 237-243, 1998.
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