Multifunctional polymerization

The A-B type iniferters are more useful than the B-B type for the more efficient synthesis of polymers with controlled structure The functionality of the iniferters can be controlled by changing the number of the A-B bond introduced into an iniferter molecule, for example, B-A-B as the bifunctional iniferter. Detailed classification and application of the iniferters having DC groups are summarized in Table 1. In Eqs. (9)—(11), 6 and 7 serve as the monofunctional iniferters, 9 and 10 as the monofunctional polymeric iniferters, and 8 and 11 as the bifunctional iniferters. Tetrafunctional and polyfunctional iniferters and gel-iniferters are used for the synthesis of star polymers, graft copolymers, and multiblock copolymers, respectively (see Sect. 5). When a polymer implying DC moieties in the main chain is used, a multifunctional polymeric iniferter can be prepared (Eqs. 15 and 16), which is further applied to the synthesis of multiblock copolymers. 

It is apparent that the mode of reaction of the hyperbranched polyesteramides must be distinctively different from those of the known commercial crosslinkers. In order to explain these results, the hyperbranched polyesteramides should in our view not be regarded as simply multifunctional polymeric crosslinkers but rather as precondensed forms of two-functional crosslinkers (the addition product of diisopropanolamine and the cyclic anhydride), as depicted in Fig. 22, left. Bearing in mind the chemical fate of benzoic acid (2.2.1, Fig. 11) which was condensed with a polyesteramide resin and which appeared to transesterify at least as fast as it esterified, the mode of reaction of polyesters comprising aromatic acid end groups must be in accordance and comprised of both transesterification and esterification. 

As an example, both monofunctional and multifunctional polymeric mercapto-esters were deposited onto optically smooth silicon wafers coated with vapor-deposited copper. The copper had been oxidized to Cu20, as verified by XPS. Infrared reflectance (RAIRS) at 81° (4 cm-1 resolution, 2000 scans) using an MCT detector yielded information on both the nature and the durability of the mercaptoester bond to the metal oxide film. A 16 cm l shift (1740— 1724 cm-1) was observed in the carbonyl absorption of stearyl thioglycolate (STG) deposited onto the Cu20 mirror. The absorption spectrum of the carbonyl region is illustrated in Fig. 11, both for the pure STG and the reacted monolayer. 

Multifunctional Polymeric Excipients in Oral Macromolecular Drug Delivery... 

Multifunctional polymeric initiators are also formed by the reaction of ozone with polyalkenes [109, 110]... 

Lee ES, Na K, Bae YH (2005) Super pH-sensitive multifunctional polymeric micelle. Nano Lett 5 325-329... 

The molecular size distributions for multifunctional polymerization leading to three-dimensional polymers are derived in a manner analogous to those for linear polymers, but with much more difficulty. The derivations have been discussed elsewhere [1,15,19], and only the results will be considered here. The results given below are based on three simplifying assumptions of ideal network formation (1) all functional groups of the same type are equally reactive (2) all groups react independently of one another and (3) no intramolecular reactions (cyclization) occur. 

Fig. 2 Multifunctional polymeric micelles composed of a block copolymer of poly(ethylene glycol) and polyaspartate with tumor selectivity for active drug targeting and pH sensitivity for intracellular site-specific drug transport. Folic acid with high tumor affinity due to the overexpression of its receptors was conjugated onto the surface of the micelle (adapted from Ref. [114] with permission)...

Bae Y, Jang WD, Nishiyama N, Fukushima S, Kataoka K. Multifunctional polymeric micelles with folate-mediated cancer cell targeting and pH-triggered drug releasing properties for active intracellular drug delivery. Mol Biosyst 2005 1 242-250. 

Berlin PA, Gibbs JM, Shen CK, et al. Multifunctional polymeric nanoparticles from diverse bioactive agents. J Am Chem Soc 2006 128 4168-4169. 

Nasongkla N, Bey E, Ren J, Ai H, Khemtong C, Guthi JS, Chin SF, Sherry AD, Boothman DA, Gao J. 2006. Multifunctional polymeric micelles as cancer targeted, MRI ultra sensitive drug delivery systems. Nano Lett 6 2427 2430. 

Azo BCs are multifunctional polymeric materials, which combine the photochemical properties of azo polymers and the microphase separation of functional BCs. On the one hand, the azo block and the other segments cannot be miscible, unlike statistically random copolymers in which the azo moieties are dispersed homogeneously over the whole bulk films. On the other hand, the azo BCs cannot form macroscopically phase-separated structures like polymer blends (Bates and Fredrichson, 1999). 

Multifunctional materials will play an important role in the development of Photonics Technology. This paper describes novel multifunctional polymeric composites for applications in both active and passive photonic components. On the molecular level, we have introduced multifunctionality by design and synthesis of chromophores which by themselves exhibit more than one functionality. At the bulk level, we have introduced the concept of a multiphasic nanostructured composites where phase separation is controlled in the nanometer range to produce optically transparent bulk in which each domain produces a specific photonic function. Results are presented from the studies of up-converted two-photon lasing, two-photon confocal microscopy, optical power limiting, photorefractivity and optical channel waveguides to illustrate the application of the multifunctional optical composites. 

PRASAD Novel Multifunctional Polymeric Composites for Photonics 535... 

Multiphasic Nanostructured Composites Bulks. A novel approach to produce multifunctional polymeric composites is to use a multiphase system with the phase separation at the nanometer scale. Since the domain sizes are much smaller than the wavelength of light, they do not scatter. The result is an optically transparent sample in which each domain may produce a different optical function. 

Polymerization is an important method for obtaining multifunctional polymeric compositive materials and is the subject of interesting scientific investigations, first of all because of a wide range of kinetic characteristics. That is why the main focus of this monograph is on kinetic models of the photoinitiated polymerization of mono- and bifunctional monomers up to the high conversion state, the derivation of these models, their analysis and comparison with the experimental data (Chapters 5-8) obtained over the last 10 years. 

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