A series of semialicyclic polyimides (PIs) have been successfully prepared by the polycondensation of two alicyclic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA) with two sulfur-containing aromatic diamines, 4,4′-thiobis[(p-phenylenesulfanyl)aniline] (3SDA) and 2,7-bis(4-aminophenylenesulfanyl)thianthrene (APTT), respectively, by a two-step polymerization procedure via the soluble poly(amic acid) (PAA) precursors. Flexible and tough PI films were obtained with a tensile strength greater than 82 MPa and elongation at breaks higher than 12%. The films showed good thermal and thermal-oxidative stability without significant weight loss up to 400 °C, both in air and nitrogen. The glass-transition temperatures of the PIs ranged from 236.5 to 274.1 °C. Good optical transparency, including the cutoff wavelengths lower than 350 nm and transmittances higher than 80% at 400 nm, was achieved for all the PI films. The refractive indices of...

High refractive index and negative pattern formation from poly(amic acid)-TiO2 nanocomposite film

Colorimetric temperature sensors are prepared from photo-crosslinkable polymers by sequentially spin-coating and crosslinking alternating layers of poly(N-isopropylacrylamide) and poly(para-methyl styrene). Layer thicknesses and copolymer chemistries are chosen to provide robust colorimetric temperature sensors that cover nearly the full visible spectrum.

http://absimage.aps.org/image/MAR12/MWS_MAR12-2011-002229.pdf

Photonic multilayer sensors from photo-crosslinkable polymer films

Rate constants for the reactions of triplet decafluorobenzophenone (3DFB) with 30 alkenes have been measured, with values in the range 107−109 L mol-1 s-1. The rate constant increases upon substitu...

Reactions of Triplet Decafluorobenzophenone with Alkenes. A Laser-Flash Photolysis Study

https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1385&context=dissertations_2

Maria C Chiappelli

Papers

Tunable Photonic Multilayers from Stimulus-Responsive, Photo-Crosslinkable Polymers