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Activated monomers

Most ion exchangers in large-scale use are based on synthetic resins—either preformed and then chemically reacted, as for polystyrene, or formed from active monomers (olefinic acids, amines, or phenols). Natural zeolites were the first ion exchangers, and both natural and synthetic zeolites are in use today. [Pg.1496]

The left-hand end of the activated monomer is sealed off by the OH terminator, but the right-hand end (with the star) is aggressively reactive and now attacks another ethylene molecule, as we illustrated earlier in Fig. 22.1. The process continues, forming a longer and longer molecule by a sort of chain reaction. The —OH used to start a chain will, of course, terminate one just as effectively, so excess initiator leads to short chains. As the monomer is exhausted the reaction slows down and finally stops. The DP depends not only on the amount of initiator, but on the pressure and temperature as well. [Pg.255]

Although the generic equation (26) remains the same for the case with initiator too, that for the active monomers is different Cy = -k Mcy + c - All other Eqs. (26) retain their form, provided Cy is replaced there by the concentration of inert monomers, M. [Pg.541]

Transition metal coupling polymerization has also been used to synthesize optically active polymers with stable main-chain chirality such as polymers 33, 34, 35, and 36 by using optically active monomers.29-31 These polymers are useful for chiral separation and asymmetric catalysis. For example, polymers 33 and 34 have been used as polymeric chiral catalysts for asymmetric catalysis. Due... [Pg.473]

Anionic polymerization of lactams was shown to proceed according to what is called the activated monomer mechanism. With bischloroformates of hydroxy-terminated poly(tetramethyleneglycol) and poly(styrene glycol) as precursors for a polymeric initiator containing N-acyl lactam ends, block copolymers with n-pyrrol-idone and e-caprolactam were obtained by bulk polymerizations in vacuum at 30 and 80 °C, respectively361. ... [Pg.30]

An interesting cationic activated monomer mechanism was reported by Penczek. [Pg.93]

Scheme 3 Proposed mechanism for NCA polymerization initiated by activated monomers... Scheme 3 Proposed mechanism for NCA polymerization initiated by activated monomers...
Other proteins within the organelle catalyze folding of the protein, often attaching cofactors or oligosaccharides and assembling them into active monomers or oligomers. [Pg.501]

Acyl-enzyme intermediate (enzyme-activated monomer, EM)... [Pg.210]

The enzymatic polymerization of lactones is explained by considering the following reactions as the principal reaction course (Fig. 9) [83,85,95,96]. The key step is the reaction of the lactone with lipase involving the ring-opening of the lactone to give the acyl-enzyme intermediate (enzyme-activated monomer,... [Pg.250]

Grossman, S.H., Pyle, J., and Steiner, R.J. (1981) Kinetic evidence for active monomers during the reassembly of denatured creatine kinase. Biochemistry 21, 6122. [Pg.1069]

Propylene oxide is a surface active monomer structurally similar to ethylene oxide and therefore of interest as a SHM W-SP, but with more than ten repeating units this polymer is not water soluble. A compositional isomer methyl vinyl ether is water soluble the adsorption behavior of this polymer (PMVE) is illustrated in Figure 4. At 1 ppm the rate of 7T increase is linear over three hours. The diffusion rate could be calculated if the W-SP s molecular weight were monodispersed. The polymer studied had a Gaussian molecular weight distribution, which is true of essentially all W-SPs even after attempts have been made to... [Pg.117]

Polyacetylenes are the most important class of synthetic polymers containing conjugated carbon-carbon double bonds. Some optically active monomers have been used with the following conclusions. Polymers of 1-alkynes having a branched side-chain assume in solution a helical conformation. A chiral side-chain induces a predominant screw sense in these helices. In particular, for alkyl branching, it has been shown that (S) monomers lead to a left-handed screw sense. [Pg.141]


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See also in sourсe #XX -- [ Pg.4 ]

See also in sourсe #XX -- [ Pg.322 , Pg.336 , Pg.342 ]




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Activated monomer acrylamide

Activated monomer cyclic ether

Activated monomer enzymatic polymerization

Activated monomer kinetics

Activated monomer lactam

Activated monomer mechanism (AMM

Activated monomer mechanism Initiation step

Activated monomer mechanism chain generation

Activated monomer mechanism description

Activated monomer mechanism polymer chain generation

Activated monomer mechanism propagation step

Activated monomer mechanism reactions

Activation of the Monomer

Active species-heterocyclic monomer

Active species-heterocyclic monomer addition

Benzene optically active monomer

Cationic Oligomerization of Oxiranes Leading to Linear Oligomers Activated Monomer Mechanism

Cationic coordination polymerization activated monomer

Cationic surface-active monomer

Enzyme-activated monomer

Lactams polymerization, activated monomer

Lactams polymerization, activated monomer mechanism

Mechanism of activated monomer

Methacrylic monomers, propagation termination activation energies

Monomer activities, concentration

Monomer activity

Monomer activity

Monomer activity measurement

Monomer activity measurement conditions

Monomer activity measurement examined

Monomer activity measurement ideality

Monomer activity measurement mixture

Monomer mechanism, activated

Monomers, optically active

Monomers, optically active polymerization

Olefin monomers propagation/termination activation

Optically active carbazole containing monomers

Optically active carbazole monomers

Polymerization activated monomer mechanism

Polymerization by activated monomer mechanism

Polymerization monomer activation

Polymerization with activated monomer

Ring-opening polymerisation monomer activation

Ring-opening polymerization activated monomer

Styrene monomers propagation/termination activation energy

Surface-active agents, grafting monomer

Surface-active monomers

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