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

Abstract

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.

Strong Screening Effect of Polyhedral Oligomeric Silsesquioxanes (POSS) Nanoparticles on Hydrogen Bonded Polymer Blends

“…The PVPh polymer (M w = 9000-10,000) was purchased from Polyscience (USA). The phenolic was synthesized through an H 2 SO 4 -catalyzed condensation reaction, producing an average molecular weight (M n ) of 500, using a procedure described previously [36][37][38]. Table 1 summarizes the molecular weights of all of the materials used in this study.…”

Online Monitoring of Polymerizations: Current Status

“…[25,26] FTIR techniques are also extensively utilized to monitor block copolymer properties, self-assembly behavior, and dissolution of symmetrical diblock copolymers. [27][28][29][30] More interesting is the ability to utilize spectroscopic analysis techniques online in a continuous flow process. The true potential of flow polymerization optimization unfolds only in combination with online monitoring tools.…”

Mesoporous Carbons Templated by PEO‐PCL Block Copolymers as Electrode Materials for Supercapacitors

“…To fabricate the mesoporous carbons, we first synthesized an amphiphilic PEO-PCL block copolymer with specific molecular weightf ractions( EO 114 -CL 92 )a st he template;i np revious studies, we found that such templates are suitable for the preparation of ordered mesoporousc arbonsw ith hexagonal cylinder and gyroid structures. [26][27][28][29] The resol-type phenolic resin and this PEO-PCL template were dissolved in EtOH at as pecific weightr atio;t he microphase transferredg radually to an ordered structurea fter evaporation-induced self-assembly and curing in the oven, with the electrode materials for EDLCs upercapacitors obtained after carbonization and activation processes (Scheme 1). The weightr atios of resol to PEO-PCLc ould be regulated during the fabrication of the mesoporousc ar-bons to induce differentt ypes of microphase separation, based on the corresponding volume fractionso ft he PCL and resol/PEOd omains.…”

“…[22,23] Many amphiphilic block copolymers have been used recently as templates for the synthesis of mesoporous carbons, including PEO-PS (poly(ethylene oxide)-block-polystyrene), [24] PEO-PMMA (poly-(methyl methacrylate)), [25] andP EO-PCL (poly(ethylene oxideblock-caprolactone)). [26] In previous studies, [26][27][28][29][30] we employed the macroinitiatoro fM PEO and the CL monomer to synthesize as eries of amphiphilic PEO-PCL block copolymers;t hese labmade templates could be tailoredw ith various molecular weights, thereby leading to variousm icrophase-separated structures. For this reason,P EO-PCL could be aw onderful candidate based on the flexibility of tunable pore size and pore structures of mesoporousc arbons.…”