Refractive index decrease during photocrosslinking in photopolymers suitable for holographic recording

Nagata, Akira; Sakaguchi, Toru; Ichihashi, Taichi; Miya, Masaru; Ohta, Koji

doi:10.1002/marc.1997.030180218

Cited by 24 publications

(10 citation statements)

References 7 publications

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“…Among them, of particular interest continue to be the polymers containing photo-cross-linkable cinnamate side-groups, frequently introduced via the chemical modification of some precursors, whose photochemistry, based mainly on the ability of chromophore to undergo trans-cis isomerization [3][4][5][6] and photodimerization upon UV irradiation [7][8][9], was widely exploited in the development of negative-working photoresists [10,11]. Moreover, further manipulation of the poly(vinylcinnamate) (PVCi) and its derivatives was essential for inducing various changes in the physical properties of thin polymeric films irradiated with linearly polarized light, more important for practical applicability (e.g., optical devices) being photoaligment regulation of the liquid crystals or photooptical control of the refractive index and birefringence in the film [7,[12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Polycinnamates and Block Co-polymers Prepared by Atom Transfer Radical Polymerization and Microwave Irradiation

Buruiana

Jitaru

Buruiană

et al. 2010

Designed Monomers and Polymers

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Homo-polymers of 2-cinnamoyloxyethyl methacrylate (PCEMA) and block co-polymers with methylmethacrylate (MMA) synthesized via copper(I)bromide/pentamethyldiethylentriamine-mediated atom transfer polymerization (ATRP) and microwave irradiation, under homo(co)polymerization conditions, are reported. Method 1 led to homo-polymers with relatively low molecular weight (PCEMA-1: 5100; PCEMA-2: 25 000), while the second method offered polymer of 100 000 average molecular weight (PCEMA-3), the polymerization being completed within 60 min. Two di-block co-polymers, poly(2-cinnamoyloxyethyl methacrylate-block-poly(methyl methacrylate)) ((PCEMA-b-PMMA)-1, (PCEMA-b-PMMA)-2) with 0.33 and, respectively, 0.5 molar fraction of photo-cross-linkable PCEMA were also prepared and utilized for this study. Subsequent gel-permeation chromatography (GPC) measurements on block co-polymers have indicated molecular weights of 24 000 and 45 700, respectively. In addition, structural characteristics for all photo-polymers were determined by FT-IR, 1 H-NMR, UV-Vis spectroscopy, AFM and SEM/ESEM measurements. Photochemistry in thin polymeric films suggested that UV irradiation is accompanied by an insolubilization of the film caused by the transformation of cinnamate moieties and the formation of intermolecular cross-links, with important effects on the morphology. As expected, it was found that by electrospinning the above photo-polymers produced electrospun fibers of small diameter.

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Section: Introductionmentioning

confidence: 99%

Polycinnamates and Block Co-polymers Prepared by Atom Transfer Radical Polymerization and Microwave Irradiation

Buruiana

Jitaru

Buruiană

et al. 2010

Designed Monomers and Polymers

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“…0.02. [4] As a further example, silicone polymers with dithienylethylene moieties along the main chain were reported to give large refractive index changes (Dn L 0.04) upon UV irradiation. [5] The UV induced polymerization of acrylate Full Paper: Poly(4-vinylbenzyl thiocyanate) (PVBT) and a copolymer of styrene and 4-vinylbenzyl thiocyanate (PST-co-VBT) were investigated with regard to changes of the refractive index under UV irradiation (k = 254 nm).…”

Section: Introductionmentioning

confidence: 99%

Refractive Index Changes in Polymers Induced by Deep UV Irradiation and Subsequent Gas Phase Modification

Langer

Kavc

Kern³

et al. 2001

Macromol. Chem. Phys.

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“…11) as observed above. This may be due to large change in the molecular polarizability during photocrosslinking resulting in a large variation in contribution from the bond refraction to the total molar refraction according to the Lorentz‐Lorenz equation 78, 79. The change in the refractive index is found to be in the range of 0.017–0.031.…”

Section: Resultsmentioning

confidence: 99%

Structure–property relationship of photoactive liquid crystalline polyethers containing benzylidene moiety

Rao

Samui

2009

J. Polym. Sci. A Polym. Chem.

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A series of main chain photoactive liquid crystalline polyethers, containing rigid bisbenzylidene photoactive mesogen and flexible methylene spacers, were synthesized by polycondensation of bisbenzylidene diols and dibromoalkanes. The polyethers were characterized with 1 H NMR, gel permeation chromatography (GPC), differential scanning calorimeter (DSC), thermo gravimetric analyzer (TGA), and polarized light optical microscopy. The individual and combined effects of spacer length and number of methoxy substituents on mesogenic and photoactive properties were investigated. Both first order and second order transition temperatures decreased with increased spacer length and the number of substituents. The combined effect of spacers and substituents drastically reduced the transition temperatures. All monomers and polymers showed mainly the smectic mesophase. In a few cases, nematic droplets along with the smectic phase were observed. The width of the liquid crystalline phase reduced with an increasing number of methoxy substituents on mesogenic unit. Variation of spacer length has a negligible effect on photocycloaddition. However, steric hinderance caused by the substituents decreased the photoactivity as the number of substituents increased. Total energies of crosslinked dimers calculated from modeling studies supported the above findings. Intermolecular photocycloaddition was also confirmed by photoviscosity measurement. The refractive index change was found to be in the range of 0.017-0.031. V V C 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem

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Refractive index decrease during photocrosslinking in photopolymers suitable for holographic recording

Cited by 24 publications

References 7 publications

Polycinnamates and Block Co-polymers Prepared by Atom Transfer Radical Polymerization and Microwave Irradiation

Polycinnamates and Block Co-polymers Prepared by Atom Transfer Radical Polymerization and Microwave Irradiation

Refractive Index Changes in Polymers Induced by Deep UV Irradiation and Subsequent Gas Phase Modification

Structure–property relationship of photoactive liquid crystalline polyethers containing benzylidene moiety

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