Amines, polymeric

Adogen 464, coupling reagent, poly(phenylene oxide), 190 Amination, polymeric organolithium compounds, 139-145... 

The initiator used is important for copolymerizations between monomers containing different polymerizing functional groups. Basic differences in the propagating centers (oxonium ion, amide anion, carbocation, etc.) for different types of monomer preclude some copolymerizations. Even when two different monomer types undergo polymerization with similar propagating centers, there may not be complete compatibility in the two crossover reactions. For example, oxonium ions initiate cyclic amine polymerization, but ammonium ions do not initiate cyclic ether polymerization [Kubisa, 1996]. 

Added salt can increase the rates of aliphatic amine polymerization more than ten fold. Salt effects are generally more marked under conditions which promote slow polymerization. Even lithium bromide increases the polymerization rate and at low temperatures in the presence of this salt, initiation is complete and polymer molecular weights are determined by monomer/initiator ratios. The time-conversion curves for the butyl monomer at low temperatures in the presence of lithium bromide are not first order throughout, but like the ethyl ester show an initial acceleration. 

Lewis acids to give the desired 2-aminopyridines (37). The dimethyldisila-nol (159), formed on amination, polymerizes to silicon oil (1(>0) or cyclic oligomers, which can be readily removed by extraction with pentane or hexane. 

This system has not been studied much recently [124, 125] save for one report by Cook [126], who found that, in the absence of amine, polymerization of a standard acrylate dental formulation proceeds to a limited extent. Polymerization is also extremely slow in the presence of primary amines or amines with no a-hydrogens. Tertiary aliphatic amines, however, accelerate the polymerization rate, as do ter-... 

In the past two years, a number of new approaches have been reported for obtaining controlled NCA polymerizations. These approaches share a common theme in that they are all improvements on the use of classical primary amine polymerization initiators. This approach is attractive since primary amines are readily available and since the initiator does not need to be removed from the reaction after polymerization. In fact, if the polymerization proceeds without any chain breaking reactions, the amine initiator becomes the C-terminal polypeptide end-group. In this manner, there is potential to form chain-end-functionahzed polypeptides or even hybrid block copolymers if the amine is a macroinitiator. The challenge in this approach is to overcome the numerous side-reactions of these systems without the luxury of a large number of experimental parameters to adjust. 

Thus the relatively weak sodium methoxide (NaOCHs) can polymerize acrylonitrile, which has a strong electronegative substituent (-CN). Vinylidene cyanide carries two —CN groups on the same carbon atom and can be polymerized even by weaker bases like water and amines. Polymerization of nonpolar monomers such as conjugated olefins, however, requires initiation by very strong bases like metal alkyls. 

Free-radical grafting is a preferred way to add functionality to polyolefins, e.g. reaction with maleic anhy de. Amine functionalized polymers can be obtained by further derivatization of carboxylic anhydride functionalized polyolefin with amines. Polymeric materials containing amino groups are important because of the chemical versatility of the amino function. Although such procedures are useful, they lack control over molecular weight and functional-group distribution in the polymer. 

A detailed survey of olefin amine polymerizations was carried out by Waymouth et al. using a variety of zirconocene and Ziegler—Natta catalysts. 5- N,N-Dimethylamino)- and 5-(A(A -diethylamino)-l-pen-tene showed low activities for zirconocene polymerization as compared to the bulkier diisopropylamino and diphenylamino derivatives (Table 1 activity for... 

G. Aldehyde-amine polymerization formation of heterocyclic nitrogen compounds (melanoidines)... 

Amines, polymeric, immobilization of the Cu(II) complexes, 134 Arsonic acid, polymer-bound, generated, 139 Aryl ethers, formation with Nafion, 51t... 

A variant of the ester polymerization but with an important additional difference is the amine polymerization resulting in polyamides (PAs), widely referred to... 

Vinyl-functional alkylene carbonates can also be prepared from the corresponding epoxides in a manner similar to the commercial manufacture of ethylene and PCs via CO2 insertion. The most notable examples of this technology are the syntheses of 4-vinyl-1,3-dioxolan-2-one (vinyl ethylene carbonate, VEC) (5, Scheme 24) from 3,4-epoxy-1-butene or 4-phenyl-5-vinyl-l,3-dioxolan-2-one (6, Scheme 24) from analogous aromatic derivative l-phenyl-2-vinyl oxirane. Although the homopolymerization of both vinyl monomers produced polymers in relatively low yield, copolymerizations effectively provided cyclic carbonate-containing copolymers. It was found that VEC can be copolymerized with readily available vinyl monomers, such as styrene, alkyl acrylates and methacrylates, and vinyl esters.With the exception of styrene, the authors found that VEC will undergo free-radical solution or emulsion copolymerization to produce polymeric species with a pendant five-membered alkylene carbonate functionality that can be further cross-linked by reaction with amines. Polymerizations of 4-phenyl-5-vinyl-l,3-dioxolan-2-one also provided cyclic carbonate-containing copolymers. 

In the past 7 years, a number of new approaches have been reported to give controlled NCA polymerizations. These approaches share a common theme in that they are all improvements on the use of conventional primary amine polymerization initiators. This approach is attractive since primary amines are readily available and since the initiator does not need to be removed from the reaction after polymerization. In... 

Recently, benzophenone-based initiators with hydrogen donating amine moieties covalently attached via an alkyl spacer were introduced as photoinitiators for vinyl polymerization [101,126-130] (see 1, Table 10). Although also following the general scheme of lype II initiators, the initiation is a monomolecular reaction, as both reactive sites are at the same molecule. Hydrogen transfer is suspected to be an intramolecular reaction. The ionic derivatives (2 and 3) shown in Table 10 are used for polymerization in the aqueous phase [131-133]. With 4,4 -diphenoxybenzophenone (4 in Table 10) in conjunction with tertiary amines, polymerization rates that are by factor of 8 higher than for benzophenone were obtained [134]. 

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