139096-37-0Relevant articles and documents
Synthesis of novel cyclosiloxane monomers containing push-pull moieties and their anionic ring opening polymerization
Perju, Elena,Cuervo-Reyes, Eduardo,Shova, Sergiu,Opris, Dorina M.
, p. 7569 - 7578 (2018/03/01)
The synthesis of three novel tetracyclosiloxane monomers modified either with a nitroaniline (NA) or with a Disperse Red 1 (DR1) push-pull group and their ring opening polymerization reaction in the presence of tetramethylammonium hydroxide are presented. The prepared monomers and polymers were characterized by different spectral methods and gel permeation chromatography. For the crystalline monomers, the structures were further proven by single crystal X-ray diffraction. Dynamic scanning calorimetry shows that the polymers that carry NA groups have a glass transition temperature (Tg) well below room temperature (RT), while the one that carries DR1 groups melts at 55 °C. The transition temperatures have a strong effect on permittivity as indicated by broadband impedance spectroscopy measurements conducted at different temperatures and frequencies. The polymers modified with NA groups have a high permittivity (maximum value of 17.3) at RT, suggesting the polar groups to be mobile and orientation polarization to be effective. However, the polar groups of the polymer modified with DR1 are frozen and thus cannot contribute to the permittivity via orientation polarization. Consequently, the permittivity is only 8.8 at RT, but increases to 22 above the melting temperature, where the dipoles are mobile. Because of the high dielectric permittivity and rather low Tg, the polymers modified with NA are attractive as active dielectric materials in actuators, capacitors, and stretchable electronics, whereas the polymer modified with DR1 may be of interest in nonlinear optical devices.
METHODS FOR OBTAINING COLORED OR CHROMIC SUBSTRATES
-
Page/Page column 7; 19; 20, (2018/01/17)
The present invention provides a post-fabrication modification approach for the fabrication of colored and chromic materials and sensors using plasma surface modification to covalently bind the coloring agent to the substrate, thus avoiding leaching of th
Synthesis and characterization of poly(ethylene glycol) diacrylate copolymers containing azobenzene groups prepared by frontal polymerization
Illescas, Javier,Ramirez-Fuentes, Yessica S.,Rivera, Ernesto,Morales-Saavedra, Omar G.,Rodriguez-Rosales, Antonio A.,Alzari, Valeria,Nuvoli, Daniele,Scognamillo, Sergio,Mariani, Alberto
experimental part, p. 3291 - 3298 (2012/05/07)
A novel polymer matrix containing amino-nitro substituted azobenzene groups was obtained by frontal polymerization. (E)-2-(Ethyl(4-((4-nitrophenyl) diazenyl)phenyl)amino)ethyl methacrylate (MDR-1) was copolymerized with poly(ethylene glycol) diacrylate (PEGDA) using this easy and fast polymerization technique. The effect of the amount of the incorporated azo-monomer into the polymer matrix was studied in detail and correlated to front velocity, maximum temperature, initiator concentration, and monomer conversion. The obtained materials were characterized by infrared spectroscopy (Fourier transform infrared), and their thermal properties were studied by thermogravimetric analysis and differential scanning calorimetry. Moreover, the optical properties of the polymers were studied by absorption spectroscopy in the UV-Vis region. Absorption spectra of the copolymers exhibit a significant blue shift of the absorption bands with respect to the azo-monomer, due to the presence of H-aggregates. Cubic nonlinear optical (NLO) characterizations of the PEGDA/MDR-1 copolymers were performed according to the Z-Scan technique. It has been proven that samples with higher MDR-1 content (0.75 mol %) exhibited outstandingly high NLO-activity with negative NLO-refractive coefficients in the promising range of n2 = -8.057 × 10-4 esu.
