Types of Functionalized Polymers

More recent efforts investigating the kinetics and mechanism of cationic polymerization of oxazolines are aimed at the preparation of various types of functional polymers as described in a recent review [181] (cf., Section IV.D). One of the examples is the development of efficient di- and tetrafunctional initiators of oxazolines polymerization, allylic or benzylic dihalides and allylic tetrahalides [182], e.g. ... 

As a new type of functional polymer materials with antibacterial activity, pyridinium-type polymers possess many unique properties in the interaction with bacteria, viruses and other negatively charged species, thus exhibiting the potential of finding wide application in many fields such as microbiology, biotechnology, water treatment, etc. The antibacterial activities of soluble and insoluble pyridinimn-... 

Fig. 1. Schematic representation of different types of functionalized polymers guest-host system(a), side-chain polymer (b), main-chain polymer (c), photo-and thermally crosslinking polymer...

The chemical structure of studied polymers is shown in Fig. 2. Three different types of functionalized polymers have been investigated. In the first case (DRGMMA) the copolymer has been got by free radical polymerization of a 1 1 molar ratio mixture of methyl methacrylate and 4 -(N-ethyl-N-(methacryloxyethyl)amino)-4-nitroazobenzene obtained by esterification with methacrylic acid of commercially available Disperse Redttl. It corresponds to... 

The siloxane polymers can be tailored to contain a few percent of vinyl groups and these can be crosslinked with polymers that contain Si-H units. We will look at these types of functional polymers in the following section. 

Secondly, hydroxyl-group-containing compounds, acting as initiator, are incorporated into chain ends. As shown in Scheme 19, depending on the nature of initiator, different types of functional polymers can be obtained. 

Pt-M catalysts (M = Ru, Ni, Co, Sn and Au) based on polymer-MWNT nanocomposites were prepared using one-step y-irradiation. Two different types of functional polymers, poly(vinylphenylboronic acid) (PVPBAc) and polyvinylpyrrolidone (PVP), were used to prepare nanocomposites. The Pt-M catalysts obtained based on polymer-MWNT nanocomposites were then characterized by XRD, TEM and elemental analysis. The catalytic efficiency of the Pt-M catalysts based on polymer-MWNT nanocomposites was also examined for CO stripping and MeOH oxidation for use in a DMFC. The catalytic efficiency of the Pt-M catalyst based on polymer-MWNT nanocomposites for MeOH oxidation followed the order Pt-Sn > Pt-Co > Pt-Ru >Pt-Au>Pt-Ni catalysts. The CO adsorption capacity of the Pt-M catalyst based on polymer-MWNT nanocomposites for CO stripping decreased in the order Pt-Ru > Pt-Sn > Pt-Au > Pt-Co > Pt-Ni catalysts. 

A substantial fraction of commercially prepared methacrylic polymers are copolymers. Monomeric acryUc or methacrylic esters are often copolymerized with one another and possibly several other monomers. Copolymerization greatiy increases the range of available polymer properties. The aH-acryhc polymers tend to be soft and tacky the aH-methacryhc polymers tend to be hard and brittie. By judicious adjustment of the amount of each type of monomer, polymers can be prepared at essentially any desired hardness or flexibiUty. Small amounts of specially functionalized monomers are often copolymerized with methacrylic monomers to modify or improve the properties of the polymer directiy or by providing sites for further reactions. Table 9 lists some of the more common functional monomers used for the preparation of methacrylic copolymers. 

Synthetic. The main types of elastomeric polymers commercially available in latex form from emulsion polymerization are butadiene—styrene, butadiene—acrylonitrile, and chloroprene (neoprene). There are also a number of specialty latices that contain polymers that are basically variations of the above polymers, eg, those to which a third monomer has been added to provide a polymer that performs a specific function. The most important of these are products that contain either a basic, eg, vinylpyridine, or an acidic monomer, eg, methacrylic acid. These latices are specifically designed for tire cord solutioning, papercoating, and carpet back-sizing. 

The functional groups introduced into polymer chains as a consequence of the initiation or termination processes can be of vital importance in determining certain polymer properties. Some such functionality is generally unavoidable. However, the types of functionality can be controlled through selection of initiator, solvent and reaction conditions and should not be ignored. 

For optimum dispersion functionality in any type of all-polymer/all-organic program, use PCA 16 or AA/NI-AS-LS. 

Olefin metathesis, an expression coined by Calderon in 1967,1 has been accurately described in Ivin and Mol s seminal text Olefin Metathesis and Metathesis Polymerization as the (apparent) interchange of carbon atoms between a pair of double bonds (ref. 2, p. 1). This remarkable conversion can be divided into three types of reactions, as illustrated in Fig. 8.1. These reactions have been used extensively in the synthesis of a broad range of both macromolecules and small molecules3 this chapter focuses on acyclic diene metathesis (ADMET) polymerization as a versatile route for the production of a wide range of functionalized polymers. 

Bis-o-quinodimethanes have also been used to functionalize [60]-fullerene by Diels Alder reaction. An example is the preparation of main-chain polymers with incorporated [60]-fullerene units [48] illustrated in Scheme 2.20. Cycloaddition of bis-diene 50 generated in situ from bis-sulfone 49 with [60]-fullerene leads to an oligomer mixture 51. Another type of functionalization is based on the... 

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). 

The investigations directed at the synthesis of thymine-substituted polymers demonstrate that the type of functional groups displayed by nucleic acid bases are compatible with ROMP. Moreover, the application of MALDI-TOF mass spectrometry to the analysis of these polymers adds to the battery of tools available for the characterization of ROMP and its products. The utility of this approach for the creation of molecules with the desired biological properties, however, is still undetermined. It is unknown whether these thymine-substituted polymers can hybridize with nucleic acids. Moreover, ROMP does not provide a simple solution to the controlled synthesis of materials that display specific sequences composed of all five common nucleic acid bases. Nevertheless, the demonstration that metathesis reactions can be conducted with such substrates suggests that perhaps neobiopolymers that function as nucleic acid analogs can be synthesized by such processes. 

The ion-exchangers used in LC consist either of an organic polymer with ionic functional groups, or silica coated with an organic polymer with ionic functional groups. The types of functional groups used are the same as described in Chapter 18. Since IEC can be carried out with an aqueous mobile phase near physiological conditions, it is an important technique in the purification of sensitive biomolecules such as proteins. 

Note 1 The polymer class name (generic name) describes the most appropriate type of functional group or heterocyclic ring system. 

When more than one type of functional group or heterocyclic system is present in the polymer structure, names should be alphabetized - for example, poly(GG ) (A-a/t-B). 

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