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Block-like

Ketene trimer can be recovered from the tarry residue of diketene distillation and converted into valuable building blocks like 1,3-cyclobutanedione and squaric acid [2892-51-5] (140,141), an important intermediate in the synthesis of pharmaceuticals and squaryHum dyes used in photostatic reproduction (142,143). [Pg.480]

Aitemativeiy, the beam end couid have compiete rotational restraint and no transverse displacement, i.e., clamped. However, a third boundary condition exists in Rgure D-3 just as in Figure D-2. That is, an axial condition on displacement or force must exist in addition to the conditions usually thought of as comprising a clamped-end condition. Note that the block-like device at the end of the beam prevents rotation and transverse deflection. A similar device will be used later for plates. Whether all of the three boundary conditions can actually be enforced depends on the order of the differential equation set when (necessarily approximate) force-strain and moment-curvature relations are substituted in Equations (D.2), (D.4), and (D.7). [Pg.497]

The results for arylsilanes are not fully understood, but the spectra may reflect partial tacticity in these polymers. Further work is needed studies of model compounds with known relative configuration would be particularly helpful. Silicon-29 NMR of polysilane copolymers also shows great promise, especially for distinguishing block-like from fully random copolymers. [Pg.14]

The living nature of the system has been utilized to prepare a range of block copolymers, including PEO-b-PPO,938 939 P(Et-EO)-b-PEO, P(Et-EO)-b-PPO and the triblock P(Et-EO)-b-PEO-b-PPO.936 Random copolymerization of EO and PO also affords narrow molecular weight distributions.940 However, for the copolymerization of PO with slower monomers, such as ECH, the more active PO incorporates preferentially to afford block-like materials. [Pg.53]

Goto, M. and Mccoy, B.J., A distribuhon kinetics model for chromatography of block-like molecules, Chem. Eng. ScL, 59, 2105, 2004. [Pg.303]

Improved methods for the synthesis of building blocks like 2-fluoro-2,2-dinitroethanol and... [Pg.2]

Newborn children are extremely sensitive to nondepolarizing muscle relaxants but may require three times as much depolarizing agent as an adult for an equivalent degree of block. Like newborn children, patients with myasthenia gravis are very sensitive to paralysis by d-tubocurarine but are resistant to succinylcholine. This altered responsiveness is probably due to the fewer number of functional AChRs at the end plate. Since neonates are very sensitive to d-tubocurarine, the dosage must be reduced and the degree of block closely monitored. [Pg.343]

Equation (E.35) is very convenient for computational work but has two disadvantages. First, the equation is restricted to Gaussian behavior of the subchains, and second, the block-like structure is not immediately recognizable. The block character of the copolymer can, however, be made evident by a different factorization. We first realize that Eq. (E.34) can be written as... [Pg.105]

Figure 5.22 29Si NMR spectrum of (PhSiMe) -co-( -Hex2Si) , a block-like copolymer. Figure 5.22 29Si NMR spectrum of (PhSiMe) -co-( -Hex2Si) , a block-like copolymer.
Somite block-like mass of mesoderm alongside neural tube forms vertebral column and segmental musculature... [Pg.255]

However, Wall and Pritchard s (94) analysis of that same study showed that although recombination hotspots do exist, 50% of the genome cannot be categorized as block-like. Several authors have therefore stressed the importance of a more dense SNP map to better define both the length and integrity of haplotype blocks (hapblocks) in the human genome (94,95). [Pg.574]

As displayed in the proposed scheme, each intramolecular transesterification randomly breaks the polymer chain. In this way, an attack on the polymer chain leads to a free residual polymer and a new randomized, modified polymer. Consequently, an original copolymer with a block-like structure would be converted to a randomized copolymer after undergoing n transesterifications [42,43]. [Pg.48]

The crystallinity, brittleness, and melting point of poly(L-LA) can be decreased by incorporation of comonomer units such as l,5-dioxepan-2-one (DXO). The large difference in reactivity ratio between the DXO and the lactides leads to a microstructure with a more block-like nature than is expected from a... [Pg.60]

By introducing DXO units into the backbone of PLA, the Tg of the lactides may be lowered to or below body temperature, and the crystallinity may be lowered. Thus, more flexible materials are obtained where the properties and degradation rate can be varied over a broad range by means of the composition. This is interesting for biomedical applications. Blends of PLA and PDXO provide additional opportunities to vary the properties. There is a large difference in reactivity ratio of LA and DXO [154]. As a result, a more block-like copolymer structure than expected for a totally random copolymer is obtained, even though the structure is somewhat randomized by transesterification reactions. In contrast, DXO and e-CL form a truly random copolymer [156]. Tri-block copolymers of LA and DXO have recently been described [303]. [Pg.97]

Loose Loose Loose Block-like piece not... [Pg.16]

Various NMR pulse sequences contain certain building blocks like BIRD, INEPT, refocusing delay etc., that perform some specific functions. A building block that serves... [Pg.306]

Copolymers with a hydrophobic polyvinyl block and a hydrophilic polypeptide block like polybutadiene-poly(L-lysine) (BK), polystyrene-poly(L-lysine) (SK),poly-butadiene-poly(L-glutamic acid) (BE), and polystyrene-poly(L-glutamic acid) (SE) are obtained by action of HC1 and HBr on copolymers BCK, SCK, BG, and SG, respectively23. ... [Pg.149]

Amino acids can be obtained by hydrolysis of proteins, chemical synthesis, fermentation (e.g. of sugars), and enzymatic processes [32], They serve similar purposes as proteins, but in addition, aspartic acid and glutamic acid were rated as top value-added chemicals, which can be converted to further fine chemicals [8]. Another example is the production of building blocks like ethylenediamine and butanediamine from serine and arginine, respectively [6],... [Pg.98]


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See also in sourсe #XX -- [ Pg.205 , Pg.206 , Pg.207 , Pg.208 , Pg.209 ]




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Comb, Brush-Block, Dendritic-Like Chimeras

Dendrimer-like star-branched block

Dendrimer-like star-branched block copolymer

Elastin-like block copolymer

Lewis-like structures for the d-block elements

Onion-like structure block copolymers

Star-like block copolymers

Tetranuclear d-block metal complexes adamantane-like structure

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