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Poly -PEP

Poly pep tide j Designation Molecular mass /Estimated number of copies per virion ... [Pg.5]

Silk fibroin has been recognized to be a semi-crystalline polymer.(228,229) Analyses of the small peptide fragments found in partial hydrolyzates of silk fibroin are not in accord with the concept of a regular chemical repeating sequence throughout the molecule.(230) Rather, a structure in which certain types of residues occur in particular portions of the chain is suggested. Specific fission of the poly(pep-fide) chain at tyrosine has allowed for the isolation of two major portions.(231)... [Pg.220]

FIGURE 5.17 Temperature versus G —the shear storage modulus at a frequency of 1.6 Hz for diblock copolymer poly(ethylene propylene)-poly(ethylethylene) (PEP-PEE). The order-disorder transition (ODT) calculated to be 291°C 1°C. (From Rosedale, J.H. and Bates, F.S., Macromolecules, 23, 2329, 1990. With permission of American Chemical Society.)... [Pg.143]

The drawbacks can be overcome by employing a block copolymer composed of poly(ethylene-a/f-propylene), PEP, and polydimethylsiloxane... [Pg.150]

The phase space of the poly(ethylene-aft-propylene)-fr-poly(d, (-lactide) (PEP-fo-PLA) system was recently explored by Schmidt and Hillmyer [63]. All equilibrium symmetries I, C, S, and G were observed. The G morphology, however, existed in only a small region between the L and C in close proximity to the ODT (Fig. 12). [Pg.156]

An example of the incorporation of an external component on the crystallization behavior of triblock copolymers was given by Schmalz et al. [126]. They obtained PS-fo-poly(ethylene-co-propylene)-fo-PE (PS-fo-PEP-fr-PE) triblock copolymers from the hydrogenation of PS-fr-PI-fo-PB. PS-fo-PEP-fr-PE triblock copolymers have the peculiarity that PEP and PE have an interaction parameter of 0.007 at 120 °C therefore, they form a homogeneous melt, which is segregated from the PS block and can be considered as an intermediate case between diblock and triblock copolymers. The crystallization of the PE block occurs at about 60 °C and the authors evaluated the influence of the incorporation of a solvent during the crystallization and segregation processes under... [Pg.54]

PE is obtained by anionic polymerization from hydrogenating a precursor 1,4-PB polymer. Since 1,4-PB contains a small fraction of 1,2-nnits the PE stndied here has two ethylene side branches per 100 backbone carbons. alt-PEP Essentially alternating poly(ethylene co-l-butene). [Pg.7]

Non-spherical micelles of poly(ethylene)(PE)-poly(ethylene-propylene)(PEP) in decane are self-assembhng in the form of extended platelets that have a crystalline PE-core and a planar PEP brush on both sides. Due to the large size of the platelets the centre of mass diffusion is extremely slow and allows a clear separation of the density fluctuation in the brush. NSE experiments [301] have been analysed in terms of the model of de Gennes [300]. The friction coefficient and modulus of the brush were found to be similar to those of a typical gel. [Pg.185]

Acetate Acetyl-P Pyr PEP poly P)n-i poly(P) Scheme 4.7 General scheme of the kinase-dependent phosphorylation of DHA with in situ regeneration of ATP. [Pg.67]

The existence of a second class of complex phases, the modulated and perforated layer structures, has largely been explored by Bates and co-workers (Forster et al. 1994 Hamley et al. 1993, 1994 Khandpur et al. 1995 Schulz et al. 1996), who used SANS and TEM to investigate shear oriented structures. The thermally-induced phase transition from the lam to the hex phase in polyolefin diblocks was studied in detail by Hamley et al. (1993, 1994) using SANS, TEM and rheology. Intermediate hexagonal modulated lamellar (HML) and hexagonal perforated layer (HPL) structures were observed on heating PEP-PEE, PE-PEP and PE-PEE diblocks, where PEP is poly(ethylene-propylene), PEE is... [Pg.46]

The mechanical and thermal properties of a range of poly(ethylene)/ poly(ethylene-propylene) (PE/PEP) copolymers have been examined by Mohajer et al. (1982). They studied the effect of variation of composition and copolymer architecture on the polymer properties by synthesizing a range of PE-PEP-PE and PEP-PE-PEP triblocks and PE-PF.P diblocks with high molecular weights (M > 200 kg mol (.The crystallinity, density and melting enthalpy for all copolymers were found to be linearly dependent on the PE content, indicating microphase separation of PE and rubbery PEP in the solid state. The... [Pg.279]

Seguela and Prud homme (1989) investigated a PE-PEP-PE triblock copolymer containing 27wt% poly(ethylene) cast from a neutral solvent close to the Tm of PE and well below it. The samples cast above Tm crystallized within the assumed hexagonal-packed cylinder microphase-separated structure. However, SAXS experiments performed on the samples cast at room temperature suggested that crystallization occurred without prior microphase separation in the melt. This path dependence is a general feature of crystallization in block copolymers. [Pg.281]

Nah, J.W., L. Yu, S.O. Han, C.H. Ahn, and S.W. Kim. 2002. Artery wall binding pep-tide-poly(ethylene glycol)-grafted-poly-(L-lysine)-based gene delivery to artery wall cells. /. Control. Release 78 273-284. [Pg.141]

PEDOT PEELS PEG PEG-Si PEI PEO PEP PER PET PG PG-zb Ph phim PHMA PI pia PIXIES poly-(3,4-ethylenedioxythiophene) parallel electron energy loss spectroscopy poly(ethylene glycol) 2-[methoxypoly(ethyleneoxy)propyl]trimethoxysilane poly(ethylene imine) poly(ethylene oxide) poly(ethylene-aZf-propylene) photoelectrorheological (effect) positron emission tomography adaptor protein G Fc domain of PG phenyl benzimidazolate poly(w-hexyl methacrylate) polyisoprene V-4-pyridyl isonicotinamide protein imprinted xerogels with integrated emission sites... [Pg.813]

Fig. 33. a Volume fraction of deuterated poly(ethylenepropylene), dPEP (full dots) and pro-tonated PEP (open circles) versus depth, for a degree of polymerization N-2300 for both constituents, after a 4 h quench to T=294 K (Tcb 365 K). Profiles are obtained with the time of flight forward recoil spectrometry (TOF-FRES). The dashed line indicates the surface domain thickness l(t). b Plot showing the growth of the surface domain thickness (t) vs t1/3. From Krausch et al. [136]... [Pg.77]


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