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Pendant groups

In the methacrylate homologous series, the effect of side-chain bulkiness is just the opposite. In this case, however, the pendant groups are flexible and offer less of an obstacle to free rotation than the phenyl group in polystyrene. As chain bulk increases, molecules are wedged apart by these substituents, free volume increases, and Tg decreases. [Pg.255]

In order to generate stereoregular (usually isotactic) polymers, the polymerization is conducted at low temperatures ia nonpolar solvents. A variety of soluble initiators can produce isotactic polymers, but there are some initiators, eg, SnCl, that produce atactic polymers under isotactic conditions (26). The nature of the pendant group can influence tacticity for example, large, bulky groups are somewhat sensitive to solvent polarity and can promote more crystallinity (14,27). [Pg.516]

The living polymerization process offers enormous flexibiUty in the design of polymers (40). It is possible to control terminal functional groups, pendant groups, monomer sequencing along the main chain (including the order of addition and blockiness), steric stmcture, and spatial shape. [Pg.516]

The Auger depth profile obtained from a plasma polymerized acetylene film that was reacted with the same model rubber compound referred to earlier for 65 min is shown in Fig. 39 [45]. The sulfur profile is especially interesting, demonstrating a peak very near the surface, another peak just below the surface, and a third peak near the interface between the primer film and the substrate. Interestingly, the peak at the surface seems to be related to a peak in the zinc concentration while the peak just below the surface seems to be related to a peak in the cobalt concentration. These observations probably indicate the formation of zinc and cobalt complexes that are responsible for the insertion of polysulfidic pendant groups into the model rubber compound and the plasma polymer. Since zinc is located on the surface while cobalt is somewhat below the surface, it is likely that the cobalt complexes were formed first and zinc complexes were mostly formed in the later stages of the reaction, after the cobalt had been consumed. [Pg.291]

The chemical structure of SBR is given in Fig. 4. Because butadiene has two carbon-carbon double bonds, 1,2 and 1,4 addition reactions can be produced. The 1,2 addition provides a pendant vinyl group on the copolymer chain, leading to an increase in Tg. The 1,4 addition may occur in cis or trans. In free radical emulsion polymerization, the cis to trans ratio can be varied by changing the temperature (at low temperature, the trans form is favoured), and about 20% of the vinyl pendant group remains in both isomers. In solution polymerization the pendant vinyl group can be varied from 10 to 90% by choosing the adequate solvent and catalyst system. [Pg.586]

The two-component waterborne urethanes are similar in nature to the one-component waterborne urethanes. In fact, many one-component PUD s may benefit from the addition of a crosslinker. The two-component urethanes may have higher levels of carboxylic acid salt stabilizer built into the backbone than is actually needed to stabilize the urethane in water. As a result, if these two-component urethane dispersions were to be used as one-component adhesives by themselves (without crosslinker), they would show very poor moisture resistance. When these two-component urethane dispersions are used in conjunction with the crosslinkers listed in Fig. 8, the crosslinkers will react with the carboxylic pendant groups built into the urethane, as previously shown in the one-component waterborne urethane section. This accomplishes two tasks at the same time (1) when the crosslinker reacts with the carboxylic acid salt, it eliminates much of the hydrophilicity associated with urethane dispersion, and (2) it crosslinks the dispersion, which imparts solvent and moisture resistance to the urethane adhesive (see phase V in Fig. 5). As a result of crosslinking, the physical properties may be modified. For example, the results may be an increase in tensile properties and a decrease in elongation. Depending upon the level of crosslinking, the dispersion may lose the ability to be repositionable. (Many of the one-component PUD s may... [Pg.797]

The ehemistry of water-soluble polymers ean take various forms. These polymers ean be anionie, cationie, or nonionie. Their polymer baekbone ean eontain hydrophilie and hydrophobie pendant groups. Branehing and polymer stereoregularity also play a role in the physieal behavior of these materials. [Pg.559]

Figure 4.14 Schemauc represemaiion of (a) 4-membered, (b) 6-membered and (c) 8-membered (LiN) heterocydes showing pendant groups on N lying both above and below the plane of the ring, (d) the laddered structure formed by lateral bonding of iwo l.iiN uniK. Figure 4.14 Schemauc represemaiion of (a) 4-membered, (b) 6-membered and (c) 8-membered (LiN) heterocydes showing pendant groups on N lying both above and below the plane of the ring, (d) the laddered structure formed by lateral bonding of iwo l.iiN uniK.
However, in LC solutes are partitioned according to a more complicated balance among various attractive forces solutes interact with both mobile-phase molecules and stationary-phase molecules (or stationary-phase pendant groups), the stationary-phase interacts with mobile-phase molecules, parts of the stationary phase may interact with each other, and mobile-phase molecules interact with each other. Cavity formation in the mobile phase, overcoming the attractive forces of the mobile-phase molecules for each other, is an important consideration in LC but not in GC. Therefore, even though LC and GC share a considerable amount of basic theory, the mechanisms are very different on a molecular level. This translates into conditions that are very different on a practical level so different, in fact, that separate instruments are required in modern practice. [Pg.151]

It is clear from the preceding discussion that organometallic photoinitiators (metal carbonyl or chelate derivatives) can provide a convenient route for synthesizing vinyl polymers with a variety of different reactive end group or photoreactive pendant groups or side chains through the polymer chain. [Pg.253]

Graft Copolymerization of Vinyl Monomers Onto Macromolecules Having Active Pendant Group via Ceric Ion Redox or Photo-Induced Charge-Transfer Initiation... [Pg.541]

OF MACROMOLECULES HAVING AN ACTIVE PENDANT GROUP INITIATED WITH CERIC ION... [Pg.546]

The synthetic methods of macromolecules having an active pendant group include (1) the transformation reactions of polymer and copolymers, and (2) polymerization and copolymerization of functional monomers having active pendant groups. The macromolecules, either in the shape of film or microbeads, can be used as the substrate. As we have mentioned previously, the rate of polymerization initiated with the Ce(IV) ion redox system is much faster than that initiated by Ce(l V) ion alone, as expressed in / r 1. Therefore, the graft... [Pg.547]

A. Grafting Reaction of Macromolecules Having 4-Tolylcarbamoyl Pendant Group... [Pg.547]

Recently, poly(itaconamide) with 4-tolylcarbamoyl pendant groups have been synthesized in our laboratory. The polymer 9 and copolymers 10 and 11 were synthesized via aminolysis of poly(N-4-methyl-phenylitaconi-... [Pg.548]

Grafting Reaction of Macromoiecuies Having 4-Tolylureido Pendant Groups... [Pg.550]

Qiu et al. [241 have reported the synthesis of macromolecules having 4-tolylureido pendant groups, such as poly(N-acryloyl-N -4-tolylurea-cvi ethyl acrylate) [po-ly(ATU-co-EA)] 18, and poly(N-methacryloyl-A/ -4-tol-ylurea-co-EA) [poly(MTU-co-EA)] 19, from the copolymerization of ATU and MTU with EA, respectively. Graft copolymerization of acrylamide onto the surface of these two copolymer films took place using the Ce(lV) ion as initiator. The graft copolymerization is proposed as Scheme (12). [Pg.550]


See other pages where Pendant groups is mentioned: [Pg.2603]    [Pg.68]    [Pg.519]    [Pg.493]    [Pg.258]    [Pg.269]    [Pg.302]    [Pg.304]    [Pg.237]    [Pg.238]    [Pg.427]    [Pg.95]    [Pg.170]    [Pg.467]    [Pg.496]    [Pg.504]    [Pg.506]    [Pg.541]    [Pg.541]    [Pg.541]    [Pg.542]    [Pg.546]    [Pg.547]    [Pg.547]    [Pg.547]    [Pg.547]    [Pg.548]    [Pg.548]    [Pg.549]    [Pg.549]    [Pg.551]    [Pg.551]   
See also in sourсe #XX -- [ Pg.3 , Pg.9 ]

See also in sourсe #XX -- [ Pg.3 , Pg.9 ]

See also in sourсe #XX -- [ Pg.56 ]

See also in sourсe #XX -- [ Pg.365 ]

See also in sourсe #XX -- [ Pg.3 , Pg.9 ]

See also in sourсe #XX -- [ Pg.365 ]




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Alkylation pendant groups

Applications of Polymers Containing Cyclophosphazene Pendant Groups

Aromatic pendant group polymers, localized

Aromatic pendant group polymers, relaxation

Block Copolymers with Pendant Metal-containing Groups

Carbonyl groups, pendant

Chain modification pendant functional groups

Cinnamoyl groups, pendant

Complex stability pendant donor groups

Conformer pendant group

Cross-linking pendant groups

Crosslinking reaction, pendant hydroxyl group

Crosslinks vs. Coordination Pendant Groups

Cyclophosphazene pendant groups

Functionalized pendant group

Grafting amino groups onto pendant

Intramolecular Effects of Pendant Groups

Isocyanate groups, pendant

Macrocycles with pendant functional groups

Macrocyclic ligands pendant groups

Networks Crosslinked by Ethynyl End-Caps and Pendant Groups

Networks from Aromatic Linear Chains Created by Reacting Backbone Diacetylene or Pendant Acetylene Groups

Nitrile groups, pendant

Oligo-and polysiloxanes with pendant oxadiazole groups

Oligothiophenes as pendant groups grafted to polymer backbones

Pendant Group Effects

Pendant acrylate groups, elastomers

Pendant alcohol groups

Pendant carborane groups, polymers with

Pendant functional group

Pendant group functionalization

Pendant group polymers

Pendant group vibrations

Pendant hydrophilic functional groups

Pendant hydrophilic functional groups copolymers

Pendant methacrylate group

Pendant photosensitive groups

Pendant sulfonic acid group

Pendant vinyl groups

Pendant-group cleavage

Phosphate-pendant groups

Photosensitizer groups, pendant

Poly pendant vinyl groups

Poly(thiophene)s with Pendant Reactive Groups

Polymer with pendant abietate and dibenzazepine groups

Polymer with pendant azide groups

Polymer with pendant cinnamoyl functional groups

Polymer with pendant maleimide groups

Polymers Containing Cyclophosphazenes as Pendant Groups

Polymers Containing Inorganic Rings or Motifs as Pendant Groups

Polymers bearing pendant aromatic groups

Polymers with Pendant Functional Groups

Polymers with Tin as a Pendant Group

Polymers with ether pendant groups

Polymers with pendant alkyne groups

Polymers with pendant carbazole groups

Polymers with pendant cinnamoyl groups

Polymers with pendant cyclic ether groups

Polymers with pendant furan groups

Polysiloxane pendant groups

Polythiophene with pendant ferrocene groups

Reactive pendant group

Rigid pendant groups, effect

Ring pendant amino groups

Styrene backbones, reactive pendant groups

Transitions pendant group effects

With ether pendant groups

With ether pendant groups deprotection

With ether pendant groups preparation

With ether pendant groups structures

With ether pendant groups synthesis

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