Polymer tadpole

Tadpole polymers are polymers consisting of one cyclic chain and one or more linear chains. Quirk and Ma182 prepared a tadpole copolymer consisting of a cyclic PBd and two linear PS chains. First they reacted PDPPE with two monofunctional living PS chains. The resulting difunctional PS was used to initiate the polymerization of butadiene. The living PBd chains were then cyclized with dichlorodimethylsilane in benzene as shown in Scheme 91. The separation of the tadpole copolymer from the polycondensates was achieved by fractional precipitation. 

A monocyclic polymer with an emanating linear or branched segment - commonly referred to as tadpoles - constitute a group of simple, cyclic topologies. Previously, the ESA-CF process has been used to construct a variety of tadpole polymers, in which the self-assembly consists of two polymer components (i.e., one unit each of monofunctional and difunctional telechelic prepolymers) and a trifunctional counteranion, leading to the formation of a tadpole (Scheme 18.2a). Conversely, a... 

Scheme 12 Some cyclic polymer structures (a) ring (b) knotted ring (c), (d) tadpoles (e) figure of eight (f) dumbbell bicycle (g) catenated ring and (h) tricycle.

Hemicyclic polymers or tadpoles Tadpoles are polymers consisting of a macrocyclic part attached to one or more linear chain fragments (see Scheme 12, strac-tures (c) and (d)). 

A tadpole polybutadiene with two linear PS chains has been prepared by Quirck and Ma living anionic poly(styryl) lithium chains were first coupled by reacting the living ends with the double diphenylethylene. Then the resulting polymer bearing two reactive catbanionic centers located in the middle of the chain was used as a bifimcdonal macroinitiator to initiate the anionic polymerization of butadiene. The two... 

Scheme 13 Synthesis of a tadpole polymer by cationic chain coupling.

Very recently, a series of smdies have focused on the preparation of tadpole polymers using or ring-opening... 

Kim, B., Kim, D., Jung, J. and Park, J. (2005). A biomimetic undulatory tadpole robot using ionic polymer-metal composite actuators. Smart Materials and Structures 14, pp. 1579-1585. 

Gao H, Wang YN, Fan YG et al (2005) Synthesis of a biodegradable tadpole-shaped polymer via the coupling reaction of polylactide onto mono(6-(2-aminoethyl)amino-6-deoxy)-beta-cyclodextrin and its properties as the new carrier of protein delivery system. J Control Release 107 158-173... 

Wen et al. synthesized an SCNP-shaped amphiphile based on poly(2-(di-methylamino)ethylmethacrylate)-Z)ZocA -polystyrene (PDMAEMA-A-PS). This polymer was cross-linked via a Menshutkin reaction where the tertiary amine was reacted with 1,4-diiodobutane to form tadpole shape amphiphiles. This design features a hydrophilic SCNP head and a hydrophobic polystyrene tail. Self-assembly of these materials resulted in micelles or vesicles based on solvent choice. In a subsequent report from the Zhao group. 

Moreover, the ESA-CF and the metathesis condensation process has been combined to produce 8-shaped polymers by three different methods (Scheme 1.15) (Tezuka et al, 2003c). These are (1) a bimolecular metathesis coupling reaction of the two ring polymers having an allyl group, (2) an intramolecular metathesis condensation of a twin-tailed tadpole polymer... 

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