Azobenzene thermoplastic elastomers

Bai S, Zhao Y. 2001. Azobenzene containing thermoplastic elastomers coupling mechan ical and optical effects. Macromolecules 34(26) 9032 9038. 

Cui L, Tong X, Yan X, Liu G, Zhao Y. 2004. Photoactive thermoplastic elastomers of azobenzene containing triblock copol5miers prepared through atom transfer radical polymerization. Macromolecules 37 7097 7104. 

A controlled free radical polymerization technique was also used, namely, atom transfer radical polymerization (ATRP), to synthesize ATE on the basis of ABA triblock copolymers (Fig. 11.3b) (Cui et al., 2004). The triblock copolymer was designed to have a rubbery midblock of poly(n-butyl acrylate) (PnBA) and two end blocks of poly 6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate) (PAzoMA) that is azo-SCLCP. For synthesis, a dibromo initiator, namely, l,l -biphenyl-4,4 -bis(2-bromoisobutyrate), can first be used to prepare the dibromo PnBA macroinitiator, which is then used to polymerize the azobenzene methacrylate monomer to yield the two end blocks of PAzoMA. This ATE is different from azo-SCLCP-grafted SBS. It is a thermoplastic elastomer, in which... 

Synthesis of liquid crystalline photoactive triblock poly(butyl acrylate) thermoplastic elastomer copolymers with methacrylate-based azobenzene-containing side-chain was reported. ... 

It was found that when the solution-cast films are stretched at temperature greater than Tg, liquid crystalline microdomains can support part of the elastic extension and, at the same time, deform to result in a long-range orientation of azobenzene mesogens. The liquid crystal orientation is retained in the relaxed film at r < Tg, which creates a thermoplastic elastomer whose glassy micro-... 

Bai, S. Zhao, Y. (2001). Azobenzene-Containing Thermoplastic Elastomers Coupling Mechanical and Optical Effects. Macromolecules, 2001, 34, 9032-9038. 

Cui, L. Tong, X. Yan, X. Liu, G. Zhao, Y. (2004). Photoactive Thermoplastic Elastomers of Azobenzene-Containing Triblock Copolymers Prepared Through Atom Transfer Radical Polymerization. Macromolecules, 2004, 37, 7097-7104. 

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