Poly semicrystalline

As shown in Table 3, the glass-transition temperatures of the amorphous straight-chain alkyl vinyl ether homopolymers decrease with increasing length of the side chain. Also, the melting points of the semicrystalline poly(alkyl vinyl ether)s increase with increasing side-chain branching. 

RF Ofstead, Cl Posner. Semicrystalline poly(vinyl alcohol) hydrogels. In J Glass, ed. Polymers in Aqueous Media. Washington, DC American Chemical Society, 1989, pp 61-72. 

GF Billovits, CJ Durning. Penetrant transport in semicrystalline poly(ethylene terephthalate). Polymer 29 1468-1478, 1988. 

Phase-transfer techniques are widely used for the preparation of polymers. For example, potassium fluoride is used to produce poly(etherketone)s under phase-transfer conditions (Scheme 10.18). Use of this reagent allows the chloroaro-matics to be used as starting material as opposed to the more expensive flu-oroaromatics that are usually employed [23]. This method is suitable for the synthesis of high molecular weight semicrystalline poly(ether ketone)s, although the presence of excess potassium fluoride in the reaction mixture can lead to degradation reactions. The use of a phase transfer catalyst can allow the use of water-soluble radical initiators, such as potassium peroxomonosulfate used to promote the free-radical polymerization of acrylonitrile [24],... 

Semicrystalline poly(ethylene-co-propylene) was prepared by the authors (1) using a Zr/Si procatalyst, (I), supported on an organic porous substrate having pore sizes of 0.1 and 2 xm. The catalyst was prepared after activating... 

Werner P, Verdejo R, Wollecke F, Altstadt V, Sandler JKW, Shaffer MSP (2005) Carbon nanofibers allow foaming of semicrystalline poly(ether ether ketone). Adv Mater 17 2864-2869... 

Specific volume and degree of crystallinity of semicrystalline poly-(chlorotrifluoroethylene) and estimated specific volumes of the pure amorphous and crystalline phases. J. Research Natl. Bur. Standards 60, 465—479 (1958). 

Specific volume-temperature dependence for semicrystalline poly-... 

The temperature independent relaxation time (t0) is also affected by the spacer length. The data of the liquid crystalline main-chain polyethers are in agreement with the data by Farrow et al. (291 on semicrystalline poly(methylene terephthalate) polymers. 

Miscibility of amorphous poly(benzyl methacrylate) (PBzMA) and semicrystalline poly(ethylene oxide) (PEO) blends were investigated by solid state NMR. Figure 6 shows the T CP/MAS NMR spectrum of the PBzMA/PEO blend in 80/20 composition and the CP/MAS NMR spectra of various compositions are shown in Fig. 7. The logarithmic plots of C... 

Hodge RM, Edward GH, Simon GP (1996) Water absorption and states of water in semicrystalline poly(vinyl alcohol) films. Polymer 37(8) 1371-1376... 

Loufakis K, Wunderlich B (1987) Thermal analysis of the conformational disorder in semicrystalline poly(vinylidene fluoride) and polytrifluoroethylene. Macromolecules, 20 2474... 

Un-cross-linked semicrystalline poly vinyl alcohol) hydrogels were prepared by solvolysis of the corresponding vinyl trifluoroacetate polymers and copolymers. The relationships between polymer crystallinity, hydrogel structure, and mechanical properties in the subject hydrogels were examined. Evidence was presented that comonomers acted to disrupt crystal structure and increase water content. The effects of copolymer structure on surface characteristics important to biomedical applications were examined, and the importance of hydrogel nonionic character was demonstrated through protein binding studies. 

Ofstead Poser Semicrystalline Poly vinyl alcohol) Hydrogels... 

Dlubek, G., De, U., Pionteck, J., Arutyunov, N., Yu. Edelmann, M., and Krause-Rehberg, R., The temperature dependence of free volume in semicrystalline poly(dimethylsiloxane) (PDMS) and its mixture with fumed silica from positron lifetime and PVT experiments, Macmmol. Chem. Phys., 206,827-840 (2005c). 

Kilburn et al. [2002] carried out a PALS study of free volume in semicrystalline poly(ethylene-co-l-octene) (PO) copolymers as well as high-density polyethylene (HDPF). The degree of crystallinity was characterized by DSC and WAXD analyses. A method was proposed to estimate the fractions of the RAF and MAF phases based on the observation that the mean thermal expansivity of free-volume holes, ea = d vh)/dt, varies as a function of Xc, which implies that the individual mean expansivities of holes in RAF and MAF phases are different. Thus, the thermal expansivity of the mean hole volume (i.e., averaged over the entire amorphous phase) may be expressed above To by... 

Dlubek et al. [2005a] have probed the free-volume characteristics of RAF and MAF in semicrystalline poly(tetrafluoroethylene) (PTFE) using PVT and PALS measurements. The temperature-dependent specific volume of the (entire) amorphous... 

Lin, J., Shenogin, S., and Nazarenko, S., Oxygen solubility and specific volume of rigid amorphous fraction in semicrystalline poly(ethylene terephthalate). Polymer, 43, 4733 (2002). 

Semicrystalline poly(phosphazene) Semi-inorganic and inorganic polymers... 

Fig. 4.166 Flexural-creep modulus of semicrystalline poly(ethylene terephthalate) at different temperatures and stress levels [12Els].

Park, Y. J., Kang, Y. S., Park. C. (2005) Micropatterning of semicrystalline poly(vinylidene fluoride) (PVDF) solutions, European Polymer Journal, Vol. 41, pp. 1002-1012, ISSN 0014-3057. 

The first quantitative analysis of RAF was carried out by analysis of the heat capacity of semicrystalline poly(oxymethylene), POM, as shown in Fig. 6.16 [20]. Clearly, the 67% of crystallinity computed from the heat of fusion, which would require a 33% amorphous fraction as indicated by the dotted line in the left trace, does... 

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