Novel Refractive Index Increase Material Based on Polystyrenes with Pendant Bicyclo Orthoester Groups upon Photoirradiation

Kudo, Hiroto; Soga, Tetsunori; Suzuki, Masaya; Nishikubo, Tadatomi

doi:10.1021/ma901060t

Cited by 7 publications

(3 citation statements)

References 37 publications

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“…BOE is also an important EM. The main method for the preparation of BOE is the exchange reaction of esters and polyols [51] . The polymerization characteristics of various EMs are shown in Table 1 [52]…”

Section: Ems and Expansion Polymerizationmentioning

confidence: 99%

Development and Dental Applications of Spiro Expanding Monomers as Antishrinkage Additives

et al. 2022

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Volumetric shrinkage is one of the main reasons cited for the failures and shortening the clinically useful life span of contemporary dental restorations. Owing to the compact and relatively more flexible cyclic structures, expanding monomers (EMs) have demonstrated essentially zero shrinkage or expansion upon polymerization. This article reviews recent studies on the new low shrinkage dental resin with spiro EMs as antishrinkage additives. This includes the most prominent classes of EMs, namely, spiroorthoesters, spiroorthocarbonates and bicycloorthoesters, along with the mechanism of expansion polymerization. A brief introduction of the development of copolymerization mechanism between EMs and dental resin is given, followed by an introduction to the cutting‐edge development and application of EMs with different side chain groups in dental materials. Furthermore, the effect of low‐shrinkage resin modified by EMs on the mechanical and biological properties was found to be within an acceptable range. The dental resins modified by spiro EMs can avoid adverse impact from the volumetric shrinkage of polymers during curing. They are materials with great potential for a variety of biomedical and clinical applications and provide guidance for the synthesis of new low shrinkage dental resin materials with good mechanical properties.

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Section: Ems and Expansion Polymerizationmentioning

confidence: 99%

Development and Dental Applications of Spiro Expanding Monomers as Antishrinkage Additives

et al. 2022

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“…In addition, the photo-Fries rearrangement in polymers bearing aromatic ester pendants was found to cause a large increase in refractive index for these polymer films (Dn¼+0.03À(+0.07)). 24,25 Very recently, Nishikubo and coworkers 26 found that photoacidgenerating agent-induced decomposition of the bicyclo orthoester pendants in a polystyrene-based polymer film increased the refractive index of this film by 0.023. Although the refractive index changes described above seem to be of sufficient magnitude to use these polymers as optical materials, it is necessary to increase the stability of the polymer refractive index and also to accelerate the photochemical transformation responsible for the refractive index change of a given polymer film.…”

Section: Introductionmentioning

confidence: 99%

Effects of aryl substituents in N-acetyl-α-dehydroarylalanine naphthyl ester additive on the photoinduced refractive index change of poly(methyl methacrylate) film

Nakajima

Komatsu

Iikura

et al. 2010

Polym J

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Aryl substituent effects on photoinduced refractive index changes were investigated with the use of poly(methyl methacrylate) (PMMA) films doped with (Z)-N-acetyl-a-dehydroarylalanine naphthyl esters ((Z)-1). Upon irradiation with Pyrex-filtered or unfiltered light from a high-pressure mercury lamp, (Z)-1 underwent heterolytic cleavage of the ester C(¼O)-O bond preferentially in both solution and PMMA film to afford arylmethylene-substituted (Z) oxazolone and naphthol derivatives as major products, irrespective of the aryl substituents introduced. Irradiation of (Z)-1 in the film with the unfiltered light enabled much more rapid photochemical transformation into the oxazolones and the intense ultraviolet absorption shifted to longer wavelength relative to that of the starting naphthyl esters. Analysis of the aryl substituent effects confirmed that the PMMA/(Z)-1 system, in which 1-naphthylmethylene-substituted oxazolone was formed along with 1-naphthol, enhanced the refractive index of this polymer film by as much as 0.020.

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“…Nishikubo et al prepared polymers with pendant bicyclo ortho ester groups and observed ¦n values in the range between +0.011 and +0.023 after photoinitiated cationic curing of the polymers. 6 The refractive index change ¦n is considered to be primarily due to the difference of molar refraction (R) of the functional groups before and after reaction, according to the LorentzLorenz equation:…”

mentioning

confidence: 99%

Refractive Index Changes in Polymers Bearing Pendant Active Ester Groups by Thermal Rearrangement Reaction

Miyasaka¹,

Higurashi²,

Kameyama³

2011

Chemistry Letters

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Linear and branched polymers bearing S-(2-benzoxazolyl) thioester groups were selectively synthesized by free radical and photoinitiated radical polymerization, respectively, of S-(2-benzoxazolyl)-4-vinylthiobenzoate. Upon heating, the pendant S-(2-benzoxazolyl) thioester groups were converted to 3-acylbenzoxazoline-2-thione groups, accompanied with a change of refractive index (Δn) of about +0.01 in both cases. The structural conversion was confirmed by UV–vis and IR spectroscopy, as well as comparison with authentic polymers bearing 3-acylbenzoxazoline-2-thione groups (similarly synthesized from 3-(4-vinylbenzoyl)benzoxazoline-2-thione). Application of such thermally induced rearrangement reactions may provide a new approach for obtaining materials whose refractive index can be changed by heat (e.g., generated by a laser beam).

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Novel Refractive Index Increase Material Based on Polystyrenes with Pendant Bicyclo Orthoester Groups upon Photoirradiation

Cited by 7 publications

References 37 publications

Development and Dental Applications of Spiro Expanding Monomers as Antishrinkage Additives

Development and Dental Applications of Spiro Expanding Monomers as Antishrinkage Additives

Effects of aryl substituents in N-acetyl-α-dehydroarylalanine naphthyl ester additive on the photoinduced refractive index change of poly(methyl methacrylate) film

Refractive Index Changes in Polymers Bearing Pendant Active Ester Groups by Thermal Rearrangement Reaction

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