Macromolecule-templated

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. 

Covalent bonding of acrylic or methacrylic monomer to the template leads to multifunctional monomers (multimonomers).If monomer units are connected by covalent bonds within the frame of the template and polymerization proceeds according to the zip mechanism , a product with ladder-type structure can he expected. The structure of products obtained depends on the competition between the reactions proceeding on the template and the reaction between groups belonging to different macromolecules (templates). Template homopolymerization in this case can he represented by the scheme given in Figure 9.1. 

Figure 17.6 FESEM images of polypyrrole nanofIber network (a) Low magnification image and (b) edge view of the polypyrrole nanofiber network. High magnification images of polypyrrole nanofiber network formed at (c) 120 s and (d) 1 b. (Reprinted with permission from Macromolecules, Template-Free Electrochemical Synthesis of Superhydrophilic Polypyrrole Nano fiber Network by J.F. Zhang, C. M. Li, S.J. Baoetal.,41, 19, 7053-7057. Copyright (2008) American Chemical Society)...

Segahnan, R.A., Schaefer, KJi., Fredrickson, G.H., Kramer, E.J., and Magonov, S.N., Topographic templat-ing of islands and holes in highly as3munetric block copolymer films. Macromolecules, 36,4498, 2003. 

Kokufuta, E Jinbo, E, A Hydrogel Capable of Facilitating Polymer Diffusion through the Gel Porosity and Its Application in Enzyme Immobilization, Macromolecules 25, 3549, 1992. Kresge, CT Leonowicz, ME Roth, WJ Vartuli, JC Beck, JS, Ordered Mesoporous Molecular Sieves Synthesized by a Liquid-Crystal Template Mechanism, Nature 359, 710, 1992. 

At this point it is necessary to make a distinction between the meanings of template and primer. The word template refers to the structural sequence of the polymerized monomeric units of a macromolecule that provides the pattern for the synthesis of another macromolecule with a complementary or characteristic sequence. The word primer, on the other hand, refers to a polymeric molecule that contains the growing point for the further addition of monomeric units. Glycogen is an example of a primer to which glucose units are added however, glycogen has no template activity. 

The next important role of biopolymers in the processes after precursor nucleation is that their macromolecules can serve as a template for silica. This has been... 

Finally, single macromolecules, because of their one-dimensional character, offer the promise of sequential side group coding, information storage, and template function in the manner that is well known in biological polymers (Figure 1). 

The spontaneous self-assembly or template-directed assembly of component monomeric units into polymeric biological macromolecules. 2. The enzyme-catalyzed joining of monomeric units (such as amino acids, sugars, nucleotides) into covalently linked oligomeric or polymeric forms. 

Khan A, Haddleton DM, Hannon MJ, Kukulj D, Marsh A. Hydrogen bond template-directed polymerization of protected 5 -acryloylnucleosides. Macromolecules 1999 32 6560-6564. 

Valkama S, Ruotsalainen T, Kosonen H, Ruokolainen J, Torkkeli M, Serimaa R, ten Brinke G, Ikkala O. Amphiphiles coordinated to block copolymers as a template for mesoporous materials. Macromolecules 2003 36 3986-3991. 

Winningham MJ, Sogah DY. A modular approach to polymer architecture control via catenation of prefabricated biomolecular segments polymers containing parallel /8-sheets templated by a phenoxathiin-based reverse turn mimic. Macromolecules 1997 30 862-876. 

Lubke C, Lubke M, Whitcombe MJ, Vulfson EN. Imprinted polymers prepared with stoichiometric template-monomer complexes efficient binding of ampiciUin from aqueous solutions. Macromolecules 2000 1433 5098-5105. 

Striegler S. Carbohydrate recognition in cross-linked sugar-templated poly(acrylates). Macromolecules 2003 36 1310-1317. 

Uezu K, Nakamura H, Kanno J, Sugo T, Goto M, Nakashio F. Metal ion-imprinted polymer prepared by the combination of surface template polymerization with postirradiation hy gamma-rays. Macromolecules 1997 30 3888-3891. 

Mathematical description of the polymerization of biological macromolecules on templates, based on simple models, has been published by Simhaet al Two types of reaction were discussed. The first type of reaction was initiated by polymerization of two monomers on each template. The reaction proceeded throughout the addition of monomer to the growing ends or by the coupling of the growing chains. In the second type of re-... 

In the case of template processes, this mechanism must be completed by terms accounting for interaction between template, monomer, and polymer. This subject is discussed in more detail in Chapter 8. Intermolecular forces lead to absorption of the monomer on the template or, if interaction between monomer and template is too weak, oligoradicals form complexes with the template. Taking into account these differences in interaction, this case of template polymerization can be divided into two types. In Type I, monomer is preadsorbed by, or complexed with, template macromolecules. Initiation, propagation and perhaps mostly termination take place on the template. The mechanism can be represented by the scheme given in Figure 2.7. 

The synthesis of biopolymers in vivo leads to macromolecules with a defined sequence of units. This effect is very important for living organisms and is different in comparison with random copolymerization in which sequences of units are distributed according to stochastic rules. On the other hand, the predicted sequence of units can be achieved by a set of successive reactions of respective monomer molecule addition. In template copolymerization, the interaction between comonomers and the template could pre-arrange monomer units defining sequence distribution in the macromolecular product. 

The problem of the relationship between reaction conditions and structure of copolymers obtained from multimethacrylate and styrene as well as from multimethacrylate and acrylic acid has been discussed. The method used was similar to the method described above. A description of the structure of these copolymers could be based on the following consideration. Because of random initiation and termination processes as well as a possibility of partial propagation across the template, we can expect that the product obtained contains unreacted double bonds and crosslinking points. The general structure of such macromolecule can be illustrated by Figure 5.1. 

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