Photo-Crosslinking of Copolymeric Methacrylates Bearing Stilbene Chromophores

2012 ◽  
Vol 67 (11) ◽  
pp. 1132-1136
Author(s):  
Angelika Jahnke ◽  
Herbert Meier
Keyword(s):  
Light Scattering ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Organic Solvents ◽  
Imaging Techniques ◽  
Ester Group ◽  
Cast Films ◽  
The Cross ◽  
Group Yield

Radical polymerization of methyl methacrylate (2) as major component and the methacrylates 1a or 1b, which contain an (E)-stilbene unit fixed by a tether to the ester group, yield easily soluble copolymers 3a, b. Whereas the dominant photoreactions in solution are (E)⇄Z) isomerizations and intra-chain [2π +2π] cycloadditions, cast films of 3a, b give an inter-chain photo-crosslinking on irradiation. Compared to homopolymers, the copolymers are not only better soluble and more easily processible, their films show less undesired light scattering. The cross-linked material is completely insoluble in organic solvents. Thus, it represents the basis for negative photoresists and the corresponding imaging techniques.

Photodegradable cross-linked polymer derived from a vinylic rotaxane cross-linker possessing aromatic disulfide axle

2013 ◽  
Vol 85 (4) ◽  
pp. 835-842 ◽  
Author(s):  
Yasuhito Koyama ◽  
Takahiro Yoshii ◽  
Yasuhiro Kohsaka ◽  
Toshikazu Takata
Keyword(s):  
Crown Ether ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Vinyl Monomer ◽  
Hydroxymethyl Group ◽  
Cross Links ◽  
Cross Linker ◽  
The Cross ◽  
Vinyl Group ◽  
Site Selective

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.

Structural control in radical polymerization with 1,1-diphenylethylene. 1. Copolymerization of 1,1-diphenylethylene with methyl methacrylate

Polymer ◽  
2002 ◽  
Vol 43 (26) ◽  
pp. 7231-7241 ◽  
Author(s):  
Sophie Viala ◽  
Klaus Tauer ◽  
Markus Antonietti ◽  
R.-P Krüger ◽  
Wolfgang Bremser
Keyword(s):  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Structural Control
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