Fabrication of Epoxy Vesicles using Self-Assembling Polystyrene–Montmorillonite Nanocomposite Reusable Template

Abstract

We report the fabrication of thermoset vesicles using a thermoplastic-clay nanocomposite vesicle reusable template. Epoxy polymer vesicles (EPV) of micrometer diameters were synthesized from bisphenol-A diglycidyl ether resin encapsulated within a self-assembled, polystyrene-montmorillonite hybrid nanocomposite (PCN) template and in situ cross-linked with polyamine curing agent. The size and wall thickness of the EPV vesicles were shown to be controlled by the epoxy resin concentration up to a critical epoxy concentration of 20 wt %, beyond which the wall thickness alone was found to be increasing. The EPVs dispersed in a polystyrene matrix at a loading of 2 wt % were found to reduce the dielectric constant of polystyrene from 3.1 to 2.0, and a linear decrease with decreasing wall thickness of the EPV, attributed to the increase in free volume involving the intrinsic porosity from the rigid epoxy vesicles and the composite, exhibited improved thermal stability also. The result suggests that vesicles produced by micromolding using self-assembled PCN can be utilized for the synthesis of polymer microcomposites having good interfacial bonding as well as low dielectric constant and good thermal stability for use in electronic packaging applications.

Aqueous Self‐Assembly of Y‐Shaped Amphiphilic Block Copolymers into Giant Vesicles

“…The other PUGs (PUG‐750, PUG‐550, and PUG‐200) also had a similar concentration‐dependent self‐assembly behavior in aqueous solution (Figures S9–S11, Supporting Information). With increasing copolymer concentrations, an increase in the wall thickness of vesicles had ever been observed by several researchers . However, an opposite change in wall thickness was found in this study.…”

Functionalization-Induced Self-Assembly of Polystyrene/Kaolinite in Situ Nanocomposites into Giant Vesicles

“…The micelles formed in solutions may be combined by the secondary interactions to form a bilayer assembly with the Janus-type-modified clay platelets connected by hydrogen-bonded interactions of the terminal hydroxyl groups and lateral interactions of −NH 2 , forming the central core, and PS segments constituting the corona, which is stabilized by π–π interactions (Figure ). , The formation of Janus-type Kaol structures by selective functionalization of platelets was reported by Hirsemann et al Self-assembly into vesicles even without any external force is attributed to the higher hydrophobic nature of the Janus structure formed by the increased vinylsilyl modification followed by incorporation of high-molecular-weight PS chains on the aluminol layer side of the platelet . A similar mechanism of formation of hybrid vesicles was reported in the case of montmorillonite-based composites by Nair et al also …”

“…There are no reports in the known literature on the exfoliation of Kaol by in situ polymerization with other monomers or the self-assembly characteristics of their hybrids. The inorganic–polymer hybrid systems formed by copolymerization of delaminated and vinyl-functionalized Kaol with other organic monomers are expected to form amphiphilic structures which can self-assemble. , In this study, the functionalization of Kaol with different ratios of aminosilyl and vinylsilyl groups was done and copolymerized with styrene for maximum delamination, leading to exfoliation forming the in situ nanocomposite. Attention was focused on the extent of amino/vinyl functionalization of Kaol and the self-assembly characteristics of its nanocomposite for fine-tuning the different nano/micro morphologies.…”