scholarly journals Methacrylic polymers bearing side-chain permanent dipole azobenzene chromophores spaced from the main chain by chiral moieties

e-Polymers ◽  
2001 ◽  
Vol 1 (1) ◽  
Author(s):  
Luigi Angiolini ◽  
Daniele Caretti ◽  
Loris Giorgini ◽  
Elisabetta Salatelli
Keyword(s):  
Thermal Properties ◽  
Nitrogen Atom ◽  
Methyl Methacrylate ◽  
Main Chain ◽  
Optically Active ◽  
Side Chain ◽  
Azobenzene Moiety

AbstractOptically active photochromic copolymers, deriving from methyl methacrylate (MMA) and the methacrylic ester of (S)-3-hydroxypyrrolidine linked through the nitrogen atom to the highly conjugated photochromic 4'-(β-cyano-β- (methylsulfonyl)vinyl)-4-azobenzene moiety, have been prepared and characterized with the aim to evaluate the effect on their chiro-optical and thermal properties exerted by the insertion of inactive MMA groups along the main chain. The results indicate that these properties are still remarkable at a content of photochromic units as low as 26 mol-%.

Second Order Nonlinear Optical Properties of Multifunctional Chiral Azobenzene Polymers

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Luigi Angiolini ◽  
Tiziana Benelli ◽  
Renato Bozio ◽  
Matteo Cozzuol ◽  
Loris Giorgini ◽  
...  
Keyword(s):  
Main Chain ◽  
Second Harmonic ◽  
Optically Active ◽  
Polymeric Films ◽  
Side Chain ◽  
Nlo Properties ◽  
Azobenzene Moiety ◽  
Corona Poling ◽  
Thermal Stability Of

AbstractCorona poling behaviours of optically active photochromic copolymers derived from methyl methacrylate (MMA) and the methacrylic ester of (S)-3- hydroxy pyrrolidine linked through the nitrogen atom to the highly conjugated photochromic 4'-(β-cyano-β-(methylsulfonyl)vinyl)-4-azobenzene moiety, have been investigated with the aim to evaluate the effect on the non-linear optical (NLO) properties originated by the presence of inactive side-chain MMA groups along the main chain. The NLO properties of in situ corona poled polymeric films have been studied by second harmonic generation (SHG) measurements. The d33 values of the investigated polymers were determined to be in the range 10-86 pm/V after corona poling. The temporal and thermal stability of the optimal SHG signals obtained after corona poling process of all the macromolecular materials has been investigated and compared. The results indicate that the maximum of these properties can be obtained at a molar content of photochromic units around 20- 40%.

Methacrylic polymers bearing side-chain permanent dipole azobenzene chromophores spaced from the main chain by chiral moieties, 3 a Synthesis and chiroptical properties of the homopolymer of (R)-3-methacryloyloxy-1-(4’-nitro-4-azobenzene)- pyrrolidine and of copolymers with the enantiomeric monomer (S)-3-methacryloyloxy-1-(4’-nitro-4-azobenzene)- pyrrolidine

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Luigi Angiolini ◽  
Loris Giorgini ◽  
Elisabetta Salatelli
Keyword(s):  
Radical Polymerization ◽  
Optical Activity ◽  
Main Chain ◽  
Optically Active ◽  
Side Chain ◽  
Chiroptical Properties

Abstract The optically active photochromic homopolymer deriving from radical polymerization of the monomer (R)-3-methacryloyloxy-1-(4’-nitro-4-azobenzene)- pyrrolidine, containing a chiral group of one prevailing configuration interposed between the methacrylic moiety and the photochromic azoaromatic chromophore, has been synthesized and characterized. Copolymers with the enantiomeric monomer (S)-3-methacryloyloxy-1-(4’-nitro-4-azobenzene)pyrrolidine have also been prepared in order to evaluate the effect on the overall optical activity of side chain chiral groups of opposite configuration in various ratios. The spectroscopic and chiroptical properties in solution of the polymeric derivatives have been assessed.

Photodegradation mechanism of phenyl isopropenyl ketone – methyl methacrylate copolymers in the solid phase and their performance as a deep UV resist

1995 ◽  
Vol 73 (11) ◽  
pp. 1841-1848 ◽  
Author(s):  
Kazuyuki Sugita ◽  
Tomohito Ishida ◽  
Masahito Kushida ◽  
Kieko Harada ◽  
Kyoichi Saito ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Main Chain ◽  
Solid Phase ◽  
Chain Scission ◽  
Quantum Yields ◽  
Side Chain ◽  
Type I ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Norrish Type

Phenyl isopropenyl ketone (PIPK) copolymer films were irradiated with a low-pressure mercury lamp, and benzoyl side-chain cleavage and main-chain scission at various temperatures were followed by UV spectral changes and gel permeation chromatography, respectively. Quantum yields of both reactions and the ratio of the latter to the former reaction increased markedly above their glass transition temperatures. The main-chain scission continued to proceed by irradiation even after the side chain ceased to split. These experimental results suggest a new reaction mechanism of photosplitting of the methyl methacrylate ester side chain on the carbon adjacent to the C=C bond followed by β-scission, in addition to the known benzoyl side-chain cleavage followed by β-scission or C=C bond formation. The enhanced quantum yield for the main-chain scission of the PIPK copolymer at 130 °C realized sensitivity of 100 mJ/cm2 as a DUV resist, which was 1200 times as high as that of poly(methyl methacrylate) exposed at room temperature and developed under similar conditions. Keywords: Norrish type I cleavage, β-scission of main chain, temperature dependence, photosplitting of ester side chain, conjugated polymer radical.

Side chain liquid crystalline polymers with an optically active polynorbornene backbone and achiral mesogenic side groups

2015 ◽  
Vol 6 (29) ◽  
pp. 5281-5287 ◽  
Author(s):  
Bin Geng ◽  
Ling-Xiang Guo ◽  
Bao-Ping Lin ◽  
Patrick Keller ◽  
Xue-Qin Zhang ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Optically Active ◽  
Side Chain ◽  
Crystalline Polymers

This work describes a series of side-on and end-on SCLCPs with an optically active polynorbornene main chain and achiral mesogens. The side-on SCLCPs tend to form achiral mesophases, while their comparative end-on analogues exhibit chiral mesophases.

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