Functional copolymers using

Compared with the aromatic electrophilic substitution approach, the SNAr approach general requires higher reaction temperatures. The polymers generally have well-defined structures. Therefore, it is more facile to control the structures of die products. In addition, it is more tolerable to some reactive functional groups, which makes it possible to synthesize reactive-group end-capped prepolymers and functional copolymers using functional monomers. 

The sequential copolymerization of cyclosiloxanes is particularly suitable for the synthesis of well-defined diblock and triblock all-siloxane functionalized copolymers. Using a monofunctional initiator leads to diblock copolymers, while triblock copolymers are formed with bifunctional initiators. Some typical examples of AB block copolymers are shown in Table 3.7. It is recommended that the less-reactive monomer be polymerized in the first step, and this is the case of the examples in which D3 and V4 are polymerized first. The comonomer should be introduced not later than at 90-95% of conversion of the first monomer, in order to avoid the processes that lead to chain randomization. Those monomers which have func-... 

Small amounts of specially functionalized monomers are often copolymerized with acryUc monomers in order to modify or improve the properties of the polymer. These functional monomers can bring about improvements either directiy or by providing sites for further reaction with metal ions, cross-linkers, or other compounds and resins. Table 9 Hsts some of the more common functional monomers used in the preparation of acryUc copolymers. 

Fig. 1. Functional monomers used in acrylamide copolymers. Methacrylamidopropyltrim ethyl ammonium chloride [51410-72-1] (1), acryloyloxyethyltrimethylammonium chioride [44992-01-0] (2), methacryloyloxyethyltrimethylammonium chloride [50339-78-1] (3), /V,/V-dimethy1aminoethy1 methacrylate [2867-47-2] (4), /V,/V-dimethylaminopropy1 acryl amide [3845-76-9] (5), diallyl dimethyl amm onium chloride...

Chain compositional heterogeneity is of particular relevance to functional copolymers which find widespread use in the coalings and adhesives industries.13,240,246 In these applications, the functional copolymer and a crosslinking agent are applied together and are cured to form a network polymer. The functional copolymers are based on functional monomers with reactive groups (e.g. OH), it is desirable that all copolymer molecules have a functionality of at least two. Nonfunctional polymer will not be incorporated and could plasticize the network or be exuded from the polymer. Monofunctional polymers are not involved in crosslink formation and will produce dangling ends. 

The above equations gave reasonably reliable M value of SBS. Another approach to modeling the elastic behavior of SBS triblock copolymer has been developed [202]. The first one, the simple model, is obtained by a modification of classical rubber elasticity theory to account for the filler effect of the domain. The major objection was the simple application of mbber elasticity theory to block copolymers without considering the effect of the domain on the distribution function of the mbber matrix chain. In the derivation of classical equation of rabber elasticity, it is assumed that the chain has Gaussian distribution function. The use of this distribution function considers that aU spaces are accessible to a given chain. However, that is not the case of TPEs because the domain also takes up space in block copolymers. 

The isopropyl group discourages P-H transfer, leading to the exclusive formation of Al-PEs. The Al-PEs can be readily transformed to a variety of functionalized PEs and to PE-based and polar polymer-based block and graft copolymers, using established methods. The selective synthesis of vinyl- and Al-terminated PEs with Zr-FI catalysts shows the critical importance of the substituent on the imine-N for polymerization catalysis. 

Acrylamide-based products, in paper manufacture, 18 115 Acrylamide copolymers, functional monomers used in, 11 628 Acrylamide gels, 1 680 Acrylamide graft copolymers, 18 625 Acrylamide polymers, 1 292, 304-333. 

These results indicate that if polydienes and similar polymers can be prepared quantitatively with tertiary amine terminal groups, then they can be combined with other halogen functional polymers using established techniques to create interesting new block copolymer systems. For example, consider the reaction between telechelic pyridine terminated polybutadiene and monofunctional bromine terminated polystyrene (equation 4) -the latter has been prepared in 95% yield. >it The product would be an ABA... 

Conformational energies are calculated for chain segments in poly(vlnyl bromide) (PVB) homopolymer and the copolymers of vinyl bromide (VBS and ethylene (E), PEVB. Semlempirical potential functions are used to account for the nonbonded van der Waals and electrostatic Interactions. RIS models are developed for PVB and PEVB from the calculated conformational energies. Dimensions and dipole moments are calculated for PVB and PEVB using their RIS models, where the effects of stereosequence and comonomer sequence are explicitly considered. It is concluded from the calculated dimensions and dipole moments that the dipole moments are most sensitive to the microstructure of PVB homopolymers and PEVB copolymers and may provide an experimental means for their structural characterization. 

Lubrication oil additives represent another important market segment for maleic anhydride derivatives Maleic anhydride is used in a multitude of applications in which a vinyl copolymer is produced hy the copolymerization of maleic anhydride with other molecules having a vinyl functionality. The use of maleic anhydride in llie manufacture of agricultural chemicals has declined ill the L ,S. since the early 1980s. 

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