A vinylic rotaxane cross-linker for toughened network polymers from the radical polymerization of vinyl monomers

2017 ◽  
Vol 8 (12) ◽  
pp. 1878-1881 ◽  
Author(s):  
J. Sawada ◽  
D. Aoki ◽  
M. Kuzume ◽  
K. Nakazono ◽  
H. Otsuka ◽  
...  

A [2]rotaxane cross-linker with one vinyl group in each component was synthesized as a vinylic cross-linker for highly toughened network polymers.

2013 ◽  
Vol 85 (4) ◽  
pp. 835-842 ◽  
Author(s):  
Yasuhito Koyama ◽  
Takahiro Yoshii ◽  
Yasuhiro Kohsaka ◽  
Toshikazu Takata

A new concept for photodegradable cross-linked polymers utilizing characteristics of rotaxane cross-links and aromatic disulfides is proposed. The cross-linked polymer is obtained by the radical polymerization of a vinyl monomer in the presence of a [3]rotaxane-type cross-linker having two radically polymerizable groups. The [3]rotaxane-type cross-linker was prepared in 93 % yield by the typical rotaxane-forming reaction using a dumbbell-shaped aromatic disulfide possessing a bis(ammonium salt) moiety and a crown ether wheel tethered by a hydroxymethyl group (96 %) and the subsequent vinyl group-endowment (80 %). The radical polymerization of methyl methacrylate (MMA) in the presence of the cross-linker (0.1 mol %) at 60 °C afforded solvent-insoluble polymer in 90 % yield. When the polymer was swollen to a gel in dimethylformamide (DMF) and a small part of the gel was UV-irradiated, the gel was promptly solubilized, probably via the photochemical scission of the S–S linkage of the interlocked aromatic disulfide, causing the efficient decomposition of the rotaxane cross-links. The recovered poly(methyl methacrylate) bearing a small amount of crown ether moiety has a molecular weight of Mn 170 kg/mol (Mw/Mn 2.1) that indicated the occurrence of the site-selective photodegradation.


2014 ◽  
Vol 5 (11) ◽  
pp. 3689-3696 ◽  
Author(s):  
Daiki Yoshimura ◽  
Shinji Yamada ◽  
Akinori Takasu

We cross-linked the polyester chains with 1,1-thiocarbonyldiimidazole to form a reversible addition–fragmentation chain-transfer (RAFT) gel, in which the trithiocarbonate moiety acted as a cross-linker. The “RAFT gel” was then swollen in vinyl monomers and styrene was radically polymerized within the gel, in which the polyester and polystyrene segments were miscible at the segment level.


2013 ◽  
Vol 46 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Keisuke Iijima ◽  
Yasuhiro Kohsaka ◽  
Yasuhito Koyama ◽  
Kazuko Nakazono ◽  
Satoshi Uchida ◽  
...  

1997 ◽  
Vol 30 (23) ◽  
pp. 7351-7354 ◽  
Author(s):  
Padma L. Nayak ◽  
Shridhara Alva ◽  
Ke Yang ◽  
Pradeep K. Dhal ◽  
Jayant Kumar ◽  
...  

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