Poly deuterated

Deuterated poly( 1,4-butadiene) (PB) networks have also been investigated [18-22], The linear precursor chains Mn from 75000 to 116000 g.mol 1) are homogeneously, selectively deuterated in the 1,4 positions, and randomly crosslinked with different types or amounts of crosslinkers. Star precursor chains deuterated at the center have also been used. 

In this case, the occurrence of two types of stereoisomeric form of disyndiotactic polymers, erythro and threo, should be emphasised let us recall that there were no differences in the stereostructure (erythro or threo) of disyndiotactic deuterated poly (a-olefins), e.g. polymers of [> - mo n od e u t e r a t e d 7-olefins, — -CH(R)-CH(2H)-]n—, when omitting different chain end groups. ... 

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]... 

Figure 3.13 shows NMR spectra of different components observed at room temperature for phenylene deuterated poly(ethylene terephthalate) films which were prepared by pressing the polymer melted at 280°C into a mould left at room temperature [24]. The spectra of the crystalline, the mobile glassy and the noncrystalline components, were selectively recorded by the subtraction method using differences in Ti, since their Tj values differed by more than one order from each other. It should be noted here... 

Fig. 3.13. Observed and simulated NMR spectra of different components for the phenylene deuterated poly(ethylene terephthalate) films, measures at 25°C. (Ref. 24.)...

Fig. 9. A comparison of the late stage scaling function of near critical polybutadiene/polyisoprene (PB/PI) mixtures at T = 55 °C with that of deuterated poly-butadiene/polybutadiene mixture [36], DPB/PB and of an iso-butyric acid/water mixture [181] I/W. Note the asymptotic exponents F(x < 1) ocx and F(x > 1) ocx-4. From Takenaka and Hash-imoto [180]...

Helix-Coil Transition in Deuterated Poly-7-Benzyl-L-Glutamate... 

FIGURE 10.11 Zimm plot of SANS data from hydrogenous and deuterated poly(methyl methacrylate) (PMMA) samples. (From Kirste et al., Polymer 16, 120, 1975. With permission.)... 

Davidson and Fasman (1967) have studied the conversion by heating of the a-form of poly-L-lysine to / -poly-L-lysine in aqueous solution by means of infrared spectroscopy and optical rotatory dispersion. A D2O solution of deuterated poly-L-lysine pD 12.3) was prepared and infrared spectra were obtained over the region of the amide I and II absorption bands (1300 to 1950cm ) at 15, 34, and 47°C (Fig. 10.14). At 15°C, the amide I and II region showed a band at 1628 cm (helical) with a shoulder at 1585 cm and a second band at 1465cm . At 34°C, there was... 

Figure 4-20. Mass average of the radius of gyration, Rg) w, of poly(styrene) as a function of the mass average molar mass m)w in carbon disulfide (O) cyclohexane ((P) and for deuterated poly(styrene) in the solid state ( ). Measurements at 35.4° C (after H. Benoit, D. Decker, and J. S. Higgins, C. Picot, J. P. Cotton, B. Farnoux, and G. Jannink).

In the present work we have studied the Cl-deuterated poly(silane)s PD4S, PD5S, PD6S and poly(di- -butylsilylenemethylene) P4SC (Scheme 1). All samples possess molecular weights above 100000 g/mol. The CD2 group in the vicinity of the silicon atoms of the polymer backbone is used as a probe for local mobility in solid-state H-NMR spectroscopy. 

Scheme 1. Cl-deuteraled poly(silane)s (R = n-propyl to n-pentyl) and poly(di-n-butylsilylenemethylene) with R = n-propyl.

Simpson, J.H., D.M. Rice, and F.E. Karasz. 1991. Investigations of H2S04-doped, ring-deuterated poly(p-phenylene vinylene) using solid-state H-2 quadrupole echo NMR-spectroscopy. Polymer 32 2340. 

Orecchini, A., C. Petrillo, G. Ruggeri, and R. Cagnolati. 2003. Neutron and x-ray scattering study of fully deuterated poly(3- -decylpyrrole). J Chem Phys 118 7690. 

Figure 5.5. The surface enrichment profile (solid line) of deuterated poly(ethylene propylene) at the surface of a blend with normal poly(ethylene propylene), measured by neutron reflectivity. The degree of polymerisation of each component was 2250 and the sample was annealed at 70 °C. The depth is normalised by the bulk correlation length and the dashed line is the prediction of equation (5.1.11). After Norton et al. (1995).

Solutions of the rodlike macroion were prepared by dissolution in methane sulfonic acid (MSA) of deuterated poly(l,4-phenylene-2,6-benzobisthiazole)(d-PBT), which was supplied by Dr. J. R. Wolfe, SRI International. Solutions were prepared in a glove box with air circulated over drierite. The solvent MSA was distilled under vacuum. The solutions were filtered several times with a teflon millipore filter into the light scattering cells in a glove box filled with dry nitrogen. Cells were sealed with flame under vacuum and then centrifuged for 24 hours before measurements. 

Variable-temperature NMR experiments provide information about the dynamic processes that occur in solids. It is well known that, for a semicrystalline polymer such as polyethylene (PE), a higher rate of cooling from the melt leads to lower crystallinity C CP/MAS NMR establishes that the cooling rate also affects the structure and motion of the amorphous domain [217]. Many of the dynamic properties of PE, such as jump rates and activation energy, can be explained in terms of chain diffusion between the phases, as detected by 2-D exchange C NMR [218]. Very slow motions in the crystalline a-form of deuterated poly(vinylidene fluoride) have also been detected by exchange NMR [219]. Double-quantum transitions can occur in materials in which spin pairs are only a few bonds apart this... 

The substitution of deuterium for hydrogen extends the usefulness of the infrared techniques, as indicated by the work of Lenormant (1950a,b) and Lenormant and Boistel (1950). In the case of poly-DL-alanine, already discussed in Section 4, Elliott (1954) found a shift of the NH stretching band toward lower frequency, with a frequency ratio of about 1.33, the expected ratio (Edsall and Scheinberg, 1940) on the basis of the increased mass of deuterium. The spectrum of deuterated poly-DL-alanine is consistent with the notion that the poljqieptide is in the a-helical form in aqueous solution. 

Deuterated poly(vinylidene fluoride) is reported to have a 6-8 °C greater melting temperature than the hydrogenated polymer.(201) It is difficult to prepare this polymer in a pure regiospecific form. The polymers cited are not regiospecific and each has a different content of reverse monomer addition. The reversion for the... 

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