Synthesis of a photosensitive polyimide containing a diazo group and its photocrosslinking reactions via a long‐lived active intermediate

Abstract

Anovel intrinsic photosensitive polyimide containing a diazo group in the main chain was prepared,and the quantum yield for the photocrosslinking reaction was determined to be 0.13 under air at room temperature by GPC measurement. The quantum yield for the photo-decomposition reaction of the diazo group was also determined to be 0.06. These values are higher by about two orders of magnitude than those for the photocrosslinking reaction of a benzophenone-containing polyimide, which is prepared from benzophenonetetracarboxylic dianhydride (BTDA) and methylene bis(2-ethylaniline) (DEDPM).The reaction was found to proceed via its singlet excited state to give a long-lived active intermediate,a carbene, which plays a great role in the increase in the photoreactivity. Characteristics of the photoreaction and the fluorescence behavior of a series of imide-substituted diphenyldiazomethanes were also investigated, showing that the reactivity of the diazo groups is not affected by the existence of charge transfer structures of the imide groups.

Quantitative Kinetic Analysis of Photochromic Reactions

“…PI(DZDAIDEDPM) was prepared from a polyimide PI(BTDA/DEDPM), which was prepared from 3,3' ,4,4' -benzophenonetetracarboxylic dianhydride and methylene bis(3-ethyl-4amino-phenylene), whose procedure is described elsewhere [5].…”

A study on the effect of spirocyclic structures in the main chain on the physical properties of copolyimides

“…[1][2][3][4][5][6][7][8][9][10][11][12] They have been employed in an increasing number of fields in the electronics industry, in applications such as alignment films for liquid crystal displays, nonlinear optical buffer layers, or as low dielectric materials. [13][14][15][16] The above properties of alicyclic polyimides arise from reduced inter-and intramolecular charge transfer (CT) interactions.…”

Optical switching of nematic liquid crystal by means of photoresponsive polyimides as an alignment layer

“…By the surface analysis, no appreciable photochemical reaction of PI was observed on the surface by light; the optical switching might be due mainly to photophysical changes of the PI surface. [12][13][14][15] However, further works are necessary to understand fully this phenomenon. The optical switching of the NLC cell with photosensitive PIs as alignment layers is a driving method of NLC, which is applicable to optical switching devices of NLCs.…”