From flexible to mesoporous polybenzoxazine resins templated by poly(ethylene oxide-b-ε-caprolactone) copolymer through reaction induced microphase separation mechanism

Chu, Wei-Cheng; Li, Jheng-Guang; Kuo, Shiao‐Wei

doi:10.1039/c3ra23447a

Cited by 33 publications

(25 citation statements)

References 103 publications

(15 reference statements)

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“…TRLS properties were fabricated and explored. Among other thermoplastic [37][38][39][40][41] and thermosetting [5][6][7] modifiers, urethane prepolymers appropriately modified the polybenzoxazine networks, endowing the BA-a/PU alloys with unique optical properties. Interestingly, TRLS properties were intrinsically associated with the BA-a/PU alloys without incorporating additional organic crystals or liquid crystals.…”

Section: Introductionmentioning

confidence: 99%

Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

Parnklang¹,

Boonyanuwat²,

Mora³

et al. 2019

Express Polym. Lett.

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Thermally reversible light scattering (TRLS) materials based solely on benzoxazine-urethane (BA-a/PU) alloys were successfully fabricated and demonstrated in this work. The alloys displayed the opaque state below 40°C. The alloys were transformed to the transparent state upon exposing to the transition temperature of 60-130 °C, depending on the molecular weights and mass concentrations of urethane prepolymers in the BA-a/PU alloys. The optical state transitions were reversible with small hystereses. BA-a/PU alloys exhibited a good optical contrast with 0%T at the light scattering state and almost 100%T at the transparent state. The alloys were glassy and form-stable up to 250 °C, due to the synergistic behavior in the glass transition temperatures. The reaction-induced phase separation effectuated by the incorporation of urethane prepolymer into thermosetting polybenzoxazine, the sizes and local concentrations of the phase-separated urethane microdomains in the supporting polybenzoxazine matrix, and the reversible dissolution and demixing of urethane microdomains and polybenzoxazine phase played crucial roles on TRLS properties of the developed benzoxazine-urethane alloys.

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Section: Introductionmentioning

confidence: 99%

Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

Parnklang¹,

Boonyanuwat²,

Mora³

et al. 2019

Express Polym. Lett.

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“…Prior to its development, the pore sizes of mesoporous carbons were limited to approximately 5-10 nm as a result of the need for copolymer templates of low molecular weight [13,14]. The EISA method made it feasible to regulate pore structures and pore sizes and allowed the preparation of various mesoporous materials from water-insoluble systems, including mesoporous silicas [2,7,8,10,[15][16][17][18], mesoporous resins [3,6,9,11], mesoporous TiO 2 [19][20][21], and mesoporous carbons [2,4,12,16,[22][23][24]. The typical procedure used to prepare ordered mesoporous carbons, so-called "template synthesis" [25][26][27][28][29][30], involves the use of mesoporous silicas as hard templates, impregnation of carbon precursors into their mesochannels, carbonization under an inert gas, and finally dissolving the hard template of the "ordered mesoporous silica" through etching in HF (aq) .…”

Section: Introductionmentioning

confidence: 99%

“…Evaporation-induced self-assembly (EISA) has been developed aggressively as a strategy for the fabrication of mesoporous nanostructures because of its broad applicability to soft templating using various block copolymer templates [1][2][3][4][5][6][7][8][9][10][11][12]. Prior to its development, the pore sizes of mesoporous carbons were limited to approximately 5-10 nm as a result of the need for copolymer templates of low molecular weight [13,14].…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Inorganic Silver and Palladium Nanostructures within Hexagonal Cylindrical Channels of Mesoporous Carbon

Tsai

Kuo

2014

Polymers

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Abstract:In this study, we prepared a mesoporous carbon with hexagonally packed mesopores through evaporation-induced self-assembly (EISA)-with the diblock copolymer poly(ethylene oxide-b-ε-caprolactone) (PEO-b-PCL) as the template (EO 114 CL 84 ), phenolic resin as the carbon precursor, hexamethylenetetramine (HMTA) as the curing agent, and star octakis-PEO-functionalized polyhedral oligomeric silsesquioxane (PEO-POSS) as the structure modifier-and subsequent carbonization. We then took the cylindrical mesoporous carbon as a loading matrix, with AgNO 3 and Pd(NO 3 ) 2 as metal precursors, to fabricate Ag nanowire/mesoporous carbon and Pd nanoparticle/mesoporous carbon nanocomposites, respectively, through an incipient wetness impregnation method and subsequent reduction under H 2 . We used transmission electron microscopy, electron diffraction, small-angle X-ray scattering, N 2 isotherm sorption experiment, Raman spectroscopy, and power X-ray diffraction to investigate the textural properties of these nanometal/carbon nanocomposites. Most notably, the Raman spectra of the cylindrical mesoporous carbon, Ag/mesoporous carbon, and Pd/mesoporous carbon revealed interesting phenomena in terms of the ratios of the intensities of the D and G bands (I D /I G ), the absolute scattering intensities, and the positions of the D bands.

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“…The combination of SAXS and TEM characterization confirmed that an apparent mesophase transformation—from disordered to short‐range ordered to cylindrical and finally to gyroidal—occurred during the curing process. Thus, this event is not only the first direct observation of a mesophase transition but also provides powerful evidence for thermal treatment (cross‐linking reactions) indeed being a key factor in the reaction‐induced self‐assembly of the final mesophase of the phenolic resin/PEO‐ b ‐PCL (matrix/template) mixture …”

Section: Resultsmentioning

confidence: 75%

In Situ Monitoring of the Reaction‐Induced Self‐Assembly of Phenolic Resin Templated by Diblock Copolymers

Chu

Jeng

et al. 2013

Macro Chemistry & Physics

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In this study, in situ small‐angle X‐ray scattering (SAXS), in situ Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM) are used to monitor the formation of ordered mesophases in cured mixtures of phenolic resin and the diblock copolymer poly(ethylene oxide‐block‐ε‐caprolactone) (PEO‐b‐PCL). SAXS and TEM analyses reveal that the mesophase of the phenolic/PEO‐b‐PCL mixture transforms sequentially from disordered to short‐range‐ordered to hexagonal‐cylindrical to gyroidal during the curing process when using hexamethylenetetramine (HMTA) as a cross‐linking agent, indicating that a mechanism involving reaction‐induced microphase separation controls the self‐assembly of the phenolic resin. In situ SAXS is also used to observe the fabrication of mesoporous phenolic resins during subsequent calcination processes.

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From flexible to mesoporous polybenzoxazine resins templated by poly(ethylene oxide-b-ε-caprolactone) copolymer through reaction induced microphase separation mechanism

Cited by 33 publications

References 103 publications

Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

Fabrication and Characterization of Inorganic Silver and Palladium Nanostructures within Hexagonal Cylindrical Channels of Mesoporous Carbon

In Situ Monitoring of the Reaction‐Induced Self‐Assembly of Phenolic Resin Templated by Diblock Copolymers

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