UV reactive polymers for refractive index modulation based on the photo-Fries rearrangement

Abstract In this study we report on the synthesis and characterization of photoreactive polymers which display large changes in their refractive index upon UV irradiation. These polymers contain aromatic ester groups which undergo a photo-Fries rearrangement from aryl esters to hydroxyketones. The polymers under investigation were poly(4-acetoxystyrene) and two derivatives of polynorbornene, poly(bicyclo[2.2.1]hept-5-ene-2-carboxylic acid, phenyl ester) and poly(bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, diphenyl ester). The kinetics of the photoreaction was studied by FTIR spectroscopy. Ellipsometric measurements of thin films showed that the photo-Fries rearrangement causes a large increase of the refractive indices in these polymers (between +0.03 and +0.05). The modulation of the refractive index is of interest for applications in the field of optics and data storage. The photoreaction also leads to an increase in surface energy as evidenced by contact angle measurements with water and diiodomethane as test liquids.

[1]  W. Kern,et al.  Photosensitive polynorbornene containing the benzyl thiocyanate group—Synthesis and patterning , 2006 .

[2]  P. Hrdlovič,et al.  Photochemical Rearrangement of Aryl, Vinyl, and Substituted Vinyl Esters and Amides of Carboxylic Acids , 1967 .

[3]  Abraham Nudelman,et al.  NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities. , 1997, The Journal of organic chemistry.

[4]  Dominique Bosc,et al.  Improvements of the Poly(vinyl cinnamate) Photoresponse in Order to Induce High Refractive Index Variations , 2004 .

[5]  G. Socrates,et al.  Infrared Characteristic Group Frequencies , 1980 .

[6]  T. Bach,et al.  Real time observation of the photo-Fries rearrangement. , 2004, The Journal of chemical physics.

[7]  R. A. Finnegan,et al.  Photochemical studies, VII. Solvent effects on the photolysis of aryl esters: fries rearrangement decarboxylation , 1968 .

[8]  P. Song,et al.  CRC handbook of organic photochemistry and photobiology , 2004 .

[9]  K. Ishihara,et al.  Design of Brønsted Acid-Assisted Chiral Lewis Acid (BLA) Catalysts for Highly Enantioselective Diels−Alder Reactions , 1998 .

[10]  Hisaya Sato,et al.  Photosulfonation of Low‐Density Polyethylene Films , 2004 .

[11]  W. Kern,et al.  Refractive index changes in polymers induced by deep UV irradiation and subsequent gas phase modification , 2001 .

[12]  Gurusamy Manivannan,et al.  Holographic Recording Materials , 1995 .

[13]  A. Trifunac,et al.  Processes in Photoreactive Polymers , 1995 .

[14]  D. Hercules,et al.  Mechanistic study of the photo-Fries rearrangement of phenyl acetate , 1974 .

[15]  C. Slugovc.  The Ring Opening Metathesis Polymerisation Toolbox , 2004 .

[16]  R. C. Weast.  CRC Handbook of Chemistry and Physics , 1973 .

[17]  R. Grubbs.  Handbook of metathesis , 2003 .

[18]  Jean-Pierre Boilot,et al.  Large and Stable Refractive Index Change in Photochromic Hybrid Materials , 1998 .

[19]  R. Weiss,et al.  Conformational control of photoinduced decarboxylation of simple aryl esters. , 2001 .

[20]  Brian H. Marcus,et al.  Holographic data storage technology , 2000, IBM J. Res. Dev..

[21]  D. Belluš.  Photo‐Fries Rearrangement and Related Photochemical [1,j] ‐Shifts (j = 3, 5, 7) of Carbonyl and Sulfonyl Groups , 2007 .

[22]  Hiroshi Ito,et al.  Poly[p-(formyloxy)styrene]: synthesis and radiation-induced decarbonylation , 1985 .