Polymers bearing reactive groups

Reactions of Polymers Bearing Reactive Groups with... 

Different reactive routes were adopted to generate in situ the block copolymers. A criterion of classification of the different methods can be tentatively made by considering the different compatibilizer precursors added to polymer blends a catalyst, a polymer bearing reactive groups, or a reactive additive. In the following, it is necessary to take into account that, often in industrial formulations, more than one compatibilizer precursor might be used. 

Biaryl derivatives bearing reactive groups have become increasingly important in industry. Uses for this class of compounds are constantly being developed in the production of high performance polymers. Materials such as 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride 1 and 4,4 -biphenol 2 are monomers employed in the manufacture of high performance polyimides or polyesters. Applications for this family of molecules have also been found both in the dye industry and in the pharmaceutical industry. 

The main objective of this chapter is to report on the preparation and characterization of thermally sensitive particles, and the pertinent aspects that should be considered before their utilization as a polymer support in the biomedical field. This is followed by an examination of the preparation of such hydrophilic thermally sensitive latex particles bearing reactive groups. Subsequently, the colloidal characterizations that are to be taken into consideration are presented. Finally, the chapter concludes by presenting and illustrating recent applications of thermally sensitive polymer colloids as solid supports in the biomedical field. 

Excess of a reagent is usually removed by polymers bearing functional groups which mimic the reactivity of the starting material (cf. Scheme 1.6.20 for general representation for detailed discussion of specific examples see Chapter 3). 

Besides the synthesis of bulk polymers, microreactor technology is also used for more specialized polymerization applications such as the formation of polymer membranes or particles [119, 141-146] Bouqey et al. [142] synthesized monodisperse and size-controlled polymer particles from emulsions polymerization under UV irradiation in a microfluidic system. By incorporating a functional comonomer, polymer microparticles bearing reactive groups on their surface were obtained, which could be linked together to form polymer beads necklaces. The ability to confine and position the boundary between immiscible liquids inside microchannels was utilized by Beebe and coworkers [145] and Kitamori and coworkers [146] for the fabrication of semipermeable polyamide membranes in a microfluidic chip via interfacial polycondensation. 

Fig. 2.14 Examples of functionalized polymer films bearing reactive groups for covalent anchoring of biomolecules. (A) amines (PANI), (B) carboxyls (PTh), (C) N-hydroxysuccinimide esters (PPy), (D) pentafluorophenyl esters (PPy), (E) N-hydroxy-phthalimide esters (PPy), (F) aldehydes (PTh) (Reprinted from Ref. [144] with the permission of Royal Society of Chemistry)...

Fig. 2 Conceptual perspective for fabricating chemisorbed ultrathin organic films from preformed polymers bearing reactive anchoring groups (see refs. [27-30, 33-41])...

The polymers obtained here, in respect to main chain, may be of the type that Brown and his coworkers previously prepared and called as pheny-T ladder prepolymer . Thus, for the time being, soluble polymers of ladder structure bearing reactive groups with moderate molecular weights (Mn = 10,000 - 0,000 and Mw = 20,000-122,000) were obtained, but attempts to make very high polymers with the molecular weight up to 10 have not been successful yet. 

Many terpenes bear reactive groups such as hydroxyl and carboxyl, which can be used for covalent attachment of terpene entities to end-functionalized polymers (Sect. 3.1) or initiation of polymerization reactions (Sect. 3.2). Sometimes, chemical modification needs to be done to turn OH or COOH into other functional groups for these two purposes. The combined properties of the biological and synthetic components have made terpene-polymer conjugates, with one or two terpene moieties at chain end(s) or in the center, very attractive materials. Nevertheless, only a few terpenes have been used for this purpose, mostly cholesterol and bUe acids. 

In 1929 Carothers proposed a generally useful differentiation between two broad classes of polymers condensation polymers in which the molecular formula of the structural unit (or units) lacks certain atoms present in the monomer from which it is formed, or to which it may be degraded by chemical means, and addition polymers, in which the molecular formula of the structural unit (or units) is identical with that of the monomer from which the polymer is derived. Condensation polymers may be formed from monomers bearing two or more reactive groups of such a character that they may condense intermolecu-larly with the elimination of a by-product, often water. The polyamides and polyesters referred to above afford prime examples of condensation polymers. The formation of a polyester from a suitable hydroxy acid takes place as follows ... 

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