Polymer synthesis solubility

A number of physical properties of polymethacrylates have been reported to depend on their stereoregularity. Among these properties ass transition temperature, Tg, and NMR spin4attice rdaxation time, Ti, may be easy of access even in the labora-toiy of polymer synthesis. Solubility of polymer is also dependent on the stereoregularity, which has been capitalized on the fractionation of the polymer in terms of the tacticity as described previously. 

The synthesis of phenoxaphosphine-containing PODs by the cyclodehydration of polyhydra2ides obtained from 2,8-dichloroformyl-lO-phenylphenoxaphosphine-lO-oxide and aUphatic and aromatic dihydra2ides has been described (60). All polymers are soluble in formic acid, y -cresol, and cone H2SO4, but insoluble or partially soluble in ben2ene, chloroform, and hexamethylphosphoric triamide. 

Tractable polymers can be prepared when amino and anhydride functions are not located on the same aromatic ring, and different strategies were employed to obtain soluble polymer. AB benzhydrol imide was prepared by polycondensation of 4-(3-amino-l-hydroxymethylene) phtlialic acid monomethyl ester in NMP. The polymer soluble in NMP has been used as adhesive and coating.56 A second approach was based on an ether imide structure. AB aminophenylether phthalic acids (Fig. 5.34) were prepared by a multistep synthesis from bisphenols.155 The products are stable as hydrochloride, and the polycondensation takes place by activation with triphenylphosphite. The polymers are soluble in an aprotic polar... 

In parallel with polymer synthesis, many activities have been directed towards soluble, well-defined oligomers. Aside from purely synthetic considerations, access to oligomers is, important for the optimization of polymer generation and for the understanding of structure/property relations in the class of PPP... 

The binders vary quite widely—the most common being starch, soy protein and latexes in conjunction with other soluble polymers. Styrene-butadiene latexes have been the most popular but ethylene-vinyl acetate binders are also used. The method of polymer synthesis provides a way of modifying the properties of the latex. For example, adjustment of the ratio of styrene butadiene in the co-polymer gives rise to different degrees of softness or hardness. This property has a profound influence on the quality of the coating. It is also possible to co-polymerise monomers so as to introduce, for example, carboxy groups on to the surface of the latex particle which in turn assist in... 

Ewen was the first to report the synthesis of stereoregular propene polymers with soluble Group 4 metal complexes and alumoxane as the co-catalyst [13], He found that Cp2TiPh2 with alumoxane and propene gives isotactic polypropene. This catalyst does not contain an asymmetric site that would be able to control the stereoregularity. A stereo-block-polymer is obtained, see Figure 10.6. Formation of this sequence of regular blocks is taken as a proof for the chain-end control mechanism. 

C02-philic molecules have been utilized for the design of metal-mobilizing ligands to be used in SCCO2 [67-69,135-137], e.g., as shown in Fig. 7a [55] and for the synthesis of surfactants that form micelles, emulsions, and micro emulsions in CO2, e.g., as shown in Fig. 7b. [70] Polymer solubility in SCCO2 has been studied [71] and utilized for polymer synthesis [72-74]. Recently, DeSimone and co-workers synthesized high-molar-mass fluoropolymers in SCCO2, and studied the polymerization kinetics [75]. 

More recently, the scope of using hyperbranched polymers as soluble supports in catalysis has been extended by the synthesis of amphiphilic star polymers bearing a hyperbranched core and amphiphilic diblock graft arms. This approach is based on previous work, where the authors reported the synthesis of a hyperbranched macroinitiator and its successful application in a cationic grafting-from reaction of 2-methyl-2-oxazoline to obtain water-soluble, amphiphilic star polymers [73]. Based on this approach, Nuyken et al. prepared catalyticaUy active star polymers where the transition metal catalysts are located at the core-shell interface. The synthesis is outlined in Scheme 6.10. 

Lohmeijer BGG, Schubert US (2003) Water-soluble building blocks for metallo-supramo-lecular polymers synthesis, complexation and decomplexation studies of poly(ethylene-oxide) moities. Macromol Chem Phys 204 1072-1078... 

Template or matrix polymerization can be defined as a method of polymer synthesis in which specific interactions between preformed macromolecule (template) and a growing chain are utilized. These interactions affect structure of the polymerization product (daughter polymer) and the kinetics of the process. The term template polymerization usually refers to one phase systems in which monomer, template, and the reaction product are soluble in the same solvent. 

Pu reported the synthesis of axially chiral-conjugated polymer 82 bearing a chiral binaphthyl moiety in the main chain by the cross-coupling polymerization of chiral bifunctional boronic acid 80 with dibromide 81 (Equation (39)). The polymer is soluble in common organic solvents, such as THE, benzene, toluene, pyridine, chlorobenzene, dichloromethane, chloroform, and 1,2-dichloroethane. The polymer composed of racemic 80 was also synthesized, and the difference of characteristics was examined. Optically active polymer 82 was shown to enhance fluorescence quantum yield up to = 0.8 compared with the racemic 82 ( = 0.5). Morphologies of the optically active and racemic polymers were also compared with a systematic atomic-force microscopy (AEM). 

Thus, the ease of polymer synthesis, the facile handling of soluble precursors, the ready thermal or chemical conversion to the final polyimide structures, and the often unprecedented polymer properties that can be obtained collectively make polyimides highly desirable for a wide range of applications. 

The preparation of soluble polymers containing species 1-4 was accomplished by the use of the polar trifluoroethoxy group as co-substituent. The partially substituted trifluoroethoxy polymer, prepared in the first step of the polymer synthesis (see Scheme II), provided a polar environment for the incorporation of the chromophoric side chains. However, the maximum loading of the polymers by the chromophores 1-4 was limited by the solubility of the polymeric products. Hence, the side group ratios for polymers 6-9 represent a maximum incorporation range of the chromophore side group by the use of this synthetic scheme. 

All of the monomers needed for the synthesis of the title polymers have to be prepared via multi-step routes as reported earlier for P-l-P-5 and P-7 [29-31] and as shown in Scheme 5 and 6 for P-6 and P-8. When the final polymer is soluble in an organic solvent, it can be readily obtained by polymerizing the bis-... 

Zhao XY, Jung KW, Janda KD, Soluble polymer synthesis an improved traceless linker methodology for aliphatic C-H bond formation, Tetrahedron Lett., 38 977-980, 1997. 

Seliger H, Aumann G, Polymer support synthesis, 5, Oligonucleotide synthesis on a polymer support soluble in water and pyridine, Tetrahedron Lett., 2911-2914, 1973. 

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