The Power of RAFT for Creating Polymers Having Imbedded Side-Chain Functionalities: Norbornenyl-Functionalized Polymers and their Transformations via ROMP and Thiol-ene Reactions

2009 ◽  
Vol 62 (11) ◽  
pp. 1507 ◽  
Author(s):  
Jun Ma ◽  
Chong Cheng ◽  
Karen L. Wooley

Robust, efficient and orthogonal chemistries are becoming increasingly important tools for the construction of increasingly sophisticated materials. In this article, the selectivity of reversible addition–fragmentation chain transfer (RAFT)-based radical polymerization of bifunctional monomers is exploited for the preparation of statistical and block copolymers that contain imbedded side-chain functionalities, which are then shown to exhibit two different orthogonal types of chemical reactivity to afford discrete nanoscale objects and functional derivative structures. Based on the radical reactivity ratios calculated from Alfrey–Price theory, a bifunctional monomer 4-(5′-norbornene-2′-methoxy)-2,3,5,6-tetrafluorostyrene (1) was designed and synthesized, for its highly reactive tetrafluorostyrenyl group relative to its norbornene (Nb) group. Selective RAFT copolymerization of 1 with styrene (St) afforded copolymers with over 50 mol-% structural units having a pendent norbornenyl functionality while maintaining narrow molecular weight distribution (polydispersity index (PDI) = 1.23). Diblock copolymers (PDI = 1.09–1.23) with Nb side-chain substituents regioselectively placed along one segment of the block copolymer structure were also prepared by RAFT copolymerizations of 1 with St or 2,3,4,5,6-pentafluorostyrene, using either polystyrene or poly(styrene-alt-maleic anhydride)-based macro chain-transfer agents. A well-defined star block copolymer (PDI = 1.23) having a poly(norbornene)-based core and polystyrene arms was obtained by ring-opening metathesis polymerization using the regioselective diblock copolymer PSt-b-P(1-co-St) as the multifunctional macromonomer and Grubbs’ catalyst (first generation) as the initiator. Photo-induced thiol-ene reactions of Nb-functionalized polymers with thiols were fast and efficient, yielding polymers with new side-chain structures.

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 317-327
Author(s):  
Chenliang Shi ◽  
Ling Lin ◽  
Yukun Yang ◽  
Wenjia Luo ◽  
Maoqing Deng ◽  
...  

AbstractThe influence of density of amino groups, nanoparticles dimension and pH on the interaction between end-functionalized polymers and nanoparticles was extensively investigated in this study. PS–NH2 and H2N–PS–NH2 were prepared using reversible addition–fragmentation chain transfer polymerization and atom transfer radical polymerization. Zero-dimensional carbon dots with sulfonate groups, one-dimensional cellulose nanocrystals with sulfate groups and two-dimensional graphene with sulfonate groups in the aqueous phase were added into the toluene phase containing the aminated PS. The results indicate that aminated PS exhibited the strongest interfacial activity after compounding with sulfonated nanoparticles at a pH of 3. PS ended with two amino groups performed better in reducing the water/toluene interfacial tension than PS ended with only one amino group. The dimension of sulfonated nanoparticles also contributed significantly to the reduction in the water/toluene interfacial tension. The minimal interfacial tension was 4.49 mN/m after compounding PS–NH2 with sulfonated zero-dimensional carbon dots.


2021 ◽  
Author(s):  
Tianyuan Pan ◽  
Bijal B. Patel ◽  
Dylan J. Walsh ◽  
Sarit Dutta ◽  
Damien Guironnet ◽  
...  

2008 ◽  
Vol 37 (11) ◽  
pp. 1174-1175 ◽  
Author(s):  
Rina Maeda ◽  
Teruaki Hayakawa ◽  
Masatoshi Tokita ◽  
Masa-aki Kakimoto ◽  
Hiroaki Urushibata

2011 ◽  
Vol 49 (12) ◽  
pp. 2653-2664 ◽  
Author(s):  
Yoshihito Ishida ◽  
Tomoyasu Hirai ◽  
Raita Goseki ◽  
Masatoshi Tokita ◽  
Masa-Aki Kakimoto ◽  
...  

Biomaterials ◽  
2012 ◽  
Vol 33 (30) ◽  
pp. 7631-7642 ◽  
Author(s):  
Tracey M. Hinton ◽  
Carlos Guerrero-Sanchez ◽  
Janease E. Graham ◽  
Tam Le ◽  
Benjamin W. Muir ◽  
...  

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