Polymer , functional, containing

In this article the term acrylamide polymer refers to all polymers which contain acrylamide as a major constituent. Consequendy, acrylamide polymers include functionalized polymers prepared from polyacrylamide by postreaction and copolymers prepared by polymerizing acrylamide (2-propenamide, C H NO) with one or more comonomers. 

Polymers. The molecular weights of polymers used in high energy electron radiation-curable coating systems are ca 1,000—25,000 and the polymers usually contain acryUc, methacrylic, or fumaric vinyl unsaturation along or attached to the polymer backbone (4,48). Aromatic or aUphatic diisocyanates react with glycols or alcohol-terrninated polyether or polyester to form either isocyanate or hydroxyl functional polyurethane intermediates. The isocyanate functional polyurethane intermediates react with hydroxyl functional polyurethane and with acryUc or methacrylic acids to form reactive p olyurethanes. 

Silicone acrylates (Fig. 5) are again lower molecular weight base polymers that contain multiple functional groups. As in epoxy systems, the ratio of PDMS to functional material governs properties of release, anchorage, transfer, cure speed, etc. Radiation induced radical cure can be initiated with either exposure of photo initiators and sensitizers to UV light [22,46,71 ] or by electron beam irradiation of the sample. 

In a third type of block copolymer formation. Scheme (3), the initiator s azo group is decomposed in the presence of monomer A in a first step. The polymer formed contains active sites different from azo functions. These sites may, after a necessary activation step, start the polymerization of the second monomer B. Actually, route (3) of block copolymer formation is a vice versa version of type (1). It has been shown in a number of examples that one starting bifunctional azo compound can be used for block copolymer synthesis following either path. Reactions of type (3) are tackled in detail in Section III of this chapter. 

SYNTHETIC METHODS SILICON-CONTAINING POLYMERS, FUNCTIONALIZED POLYOLEFINS, AND TELECHELICS... 

Figure 3. Molecular weight of the degrading polymer disc containing 0.25% anydride as a function of time. (Reproduced with permission from ref. 7. Copyright 1991 Elsevier Science Publishers.)...

Step polymerizations of linear chains can involve either two different bifunctional monomers in which each monomer possesses only one type of functional group (commonly represented by X-X or Y-Y), or a single monomer containing both types of functional groups (common representation X-Y). However, whatever the monomer type, a linear polymer molecule contains, on average, one functional group of each species per chain (molecule). 

Isocyanide polymers functionalized with amino acid groups, typically di-or tripeptides containing histidine or serine, give enantioselective deacylation and rate enhancements. Their activity is increased by addition of cationic surfactants (Visser et al., 1985). 

These novel carbon nanostructures can also be modified by (a) doping, that is the addition of foreign atoms into the carbon nanostructure, (b) by the introduction of structural defects that modify the arrangement of the carbon atoms and (c) by functionalization involving covalent or noncovalent bonding with other molecules. These modifications opened up new perspectives in developing novel composite materials with different matrices (ceramic, polymer and metals). For example, polymer composites containing carbon nanostructures have attracted considerable attention due to... 

FIGURE 14.10 Logarithm of the relaxation modulus as a function of temperature for three polymer samples. Sample (a) is (largely) crystalline vinyl pol5uner sample (b) is an amorphous vinyl polymer that contains light cross-linking and sample (c) is an amorphous vinyl pol5uner. The Tg for the amorphous polymer is about 100°C and the for the crystalline polymer is about 180°C. 

A functional polymer is a polymer that contains a functional group, such as a carboxyl or hydroxyl group. Functional polymers are of interest because the functional group has a desired property or can be used to attach some moiety with the desired property [Patil et al., 1998], For example, a medication such as chloroamphenicol, a broad-spectrum antibiotic,... 

A useful method for analyzing copolymer composition as a function of conversion is that developed by Skeist [1946], Consider a system initially containing a total of M moles of the two monomers and in which the copolymer formed is richer in monomer Mi that is the feed (i.e., F >/i). When dM moles of monomers have been copolymerized, the polymer will contain F dM moles of monomer 1 and the feed will contain (M — dM)(f — df ) moles of monomer 1. A material balance for monomer 1 requires that the moles of Mi copolymerized equal the difference in the moles of Mi in the feed before and after reaction, or... 

Takata and Endo, 1988]. A cyclic carbonate and cyclic ether are eliminated as by-products in reaction pathways a and b, respectively. Polymer LXXIV contains both ether and carbonate functional groups in the polymer chain. 

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