Photocycloaddition‐induced preparation of nanostructured, cyclic polymers using biscinnamated or biscoumarinated oligo(ethylene glycol)s

Nakayama, Yasuhide; Matsuda, Takehisa

doi:10.1002/pola.20774

Cited by 21 publications

(13 citation statements)

References 88 publications

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“…Though their dimer has no absorption peak between 250 and 350 nm, both the trans-and cis-monomers have an absorption peak at 280 nm. [34,35] When only trans-cis isomerization proceeds, an isosbestic point appears at 250 nm. As shown in Figure S3, Supporting Information, the disappearance of the isosbestic point in the PCEMA-g-PDMS spectra demonstrates that the cinnamoyl groups of PCEMA-g-PDMS undergo dimerization with isomerization under UV exposure.…”

Section: Resultsmentioning

confidence: 99%

Photoresponsive Polymer Films with Directly Micropatternable Surfaces Based on the Change in Free Volume by Photo‐Crosslinking

Noguchi

Akioka

Kojima

et al. 2022

Adv Materials Inter

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micropatterns are generated by selectively exposing photoreactive or photoresponsive polymer films to ultraviolet (UV) light in a photo-crosslinking or photodecomposition process and subsequently dissolving the selected areas of the film surfaces using an appropriate solvent. Photo lithography is widely employed as a high-resolution technique because it is suitable for large-area surface patterning with good alignment. However, it is not cost-effective because of the requirement of some complicated processes. In nanoimprint lithography based on pattern transfer processes, the patterning of polymers is fabricated by trapping a solid-state pattern by either cooling the molded material or UV-photocuring the polymer precursor after a mold is pressed against a softened thermoplastic polymer or a liquid polymer precursor. The softened thermoplastic polymer and liquid polymer precursor are driven into recessed portions of the mold by applying pressure, adhesion, or capillarity. Polymers to be patterned can be spin-cast, dispensed as droplets, or allowed to fill the space between the mold and substrate by capillary forces. [3,8,9] Recently, azopolymers with phototunable physical and chemical properties were also used in nanoimprint lithography for directional photo-manipulation of nanopatterns and micro-photo-actuators. [10,11] Nanoimprint lithography is the simplest way for producing large-area nanostructures in a low-cost and high-resolution patterning technique. However, it commonly requires high pressure, which increases the possibility of damage to the mold and substrate. Further, in nanoimprint lithography, mold fabrication using the conventional lithographic process and reactive ion etching facilities is indispensable. Simplified micropatterning techniques are necessary for surface patterning with polymers to achieve costeffective nano-and micropatterning with multiple shapes and scales. In particular, simple and cost-effective microfabrication technologies are required in developing low-cost devices and disposable chips for diagnosing diseases even though their resolution is not very high.Stimuli-responsive polymers undergo abrupt changes in their structures and properties in response to external stimuli, [12][13][14][15] such as pH, [16] temperature, [17][18][19][20] electric field, [21,22] and light. [23] According to previous studies, the stimuli-responsive behavior of the polymers is based on drastic changes in their affinity for solvents or in the osmotic pressure induced by Photoresponsive polymers, whose structures or properties change when exposed to ultraviolet (UV) light, have been studied for the fabrication of micro-and nano-devices for various applications. Herein, photoresponsive polymer films are investigated with directly micropatternable surfaces formed by only UV exposure without the development process using solvents. The photoresponsive polymer films are designed based on the decrease in free volume induced by the photodimerization of cinnamoyl groups. The photoresponsive polymers are synthesi...

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Section: Resultsmentioning

confidence: 99%

Photoresponsive Polymer Films with Directly Micropatternable Surfaces Based on the Change in Free Volume by Photo‐Crosslinking

Noguchi

Akioka

Kojima

et al. 2022

Adv Materials Inter

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“…Apart from the chain growth polymerization systems, photo‐induced step growth polymerizations are also emerging as an increasingly attractive topic in polymer synthesis. Various photoreactions or photoinduced reactions, such as thiol‐ene reaction,9 photodimerization of cinnamates or coumarinates,10 photodimerization of 2‐furanacrylates,11 photoinduced electron transfer of iodonium salt,12 light induced nitrile imine‐mediated tetrazole‐ene cycloaddition (NITEC),13 UV‐light induced Diels–Alder reaction,14 etc., have been used for step growth polymerizations. In addition, AB‐type of monomers possessing aliphatic hydroxyl and photo labile benzodioxinones (as masked COOH) was also used for the synthesis of oligo polyester as a demonstration of the concept of photo induced step growth polymerization 15.…”

Section: Reaction Conditions and Results Of The Polymerizations Throumentioning

confidence: 99%

Visible Light Catalyzed Step‐Growth Polymerization through Mizoroki–Heck Coupling Reaction

Jia

Zhang

et al. 2020

Macromol. Rapid Commun.

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The results of polymer synthesis via visible light (blue light λ = 465 nm) and a Pd‐catalyzed Mizoroki–Heck coupling reaction at ambient temperature are reported. The kinetic study demonstrates that the polymerization rate is faster under light irradiation than that in the dark, affording larger molecular weight of polymer product in the former. A mechanistic study using 19F NMR indicates that light can activate the oxidative addition step, increasing the rate of formation of the oxidative addition intermediate. The present work not only reveals a new mechanism of light's effect on Mizoroki–Heck coupling reaction in the absence of sensitizer, but also represents the first example of its application in step‐growth polymerization.

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“…If the trans-cis isomerization solely proceeds, an isosbestic point appears at 250 nm. 21 The disappearance of the isosbestic point in the spectra clearly showed that dimerization competes with isomerization in the sample during photoirradiation (Figure 2a).…”

Section: Resultsmentioning

confidence: 99%

Photoinduced mendable network polymer from poly(butylene adipate) end-functionalized with cinnamoyl groups

Oya

Sukarsaatmadja

Ishida

et al. 2012

Polym J

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A network polymer with photoinduced mending abilities was prepared from cinnamoyl-telechelic prepolymer of poly(butylene adipate), PBAC 2 , and a tetra-cinnamoyl linker, C 4 , by photodimerization. The photodimerization reaction of the cinnamoyl groups was analyzed using both ultraviolet (UV)/visible (vis) and infrared (IR) spectroscopy. In the reaction, the isomerization of the cinnamate group from the trans to the cis conformation competes with the dimerization reaction of cinnamates. The fractions of dimer and isomer populations estimated from the UV/vis spectra revealed that dimerization was the more preferred reaction at temperatures higher than the melting point of PBAC 2 . When a film of the network polymer was damaged by tapping, the cinnamate dimers dissociated to form cinnamate monomers due to the reversibility of the dimerization. To recover the network structure, these monomers could be dimerized once again through a photoirradiation process. These results show that cracks in the network polymer can be recovered through photoirradiation.

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Photocycloaddition‐induced preparation of nanostructured, cyclic polymers using biscinnamated or biscoumarinated oligo(ethylene glycol)s

Cited by 21 publications

References 88 publications

Photoresponsive Polymer Films with Directly Micropatternable Surfaces Based on the Change in Free Volume by Photo‐Crosslinking

Photoresponsive Polymer Films with Directly Micropatternable Surfaces Based on the Change in Free Volume by Photo‐Crosslinking

Visible Light Catalyzed Step‐Growth Polymerization through Mizoroki–Heck Coupling Reaction

Photoinduced mendable network polymer from poly(butylene adipate) end-functionalized with cinnamoyl groups

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