Formation of Porous Epoxy Micro-beads from a Single Droplet of Epoxy-Polyamide-Ammonium Bicarbonate at Different Temperatures

Leemsuthep, Anusha; Zakaria, Zaidi; Tanrattanakul, Varaporn; Lan, Du Ngoc Uy

doi:10.5109/4480710

Cited by 2 publications

(2 citation statements)

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“…The most common techniques for fabricating porous microbead are based on immiscibility of resin materials and a medium phase, such as epoxy in water [20] and epoxy in oil [21]. The porous beads are formed by an emulsification technique or a dropping technique [22]. Conductive material such as carbon black can be added to produce conductive epoxy porous beads [23,24].…”

Section: Gas Phase In Gel Stage  Foamablementioning

confidence: 99%

“…In this technique, chemical blowing agents are used, and the foaming process is initiated in the resin state or in the early cured state. Therefore, the technique is highly dependent on the decomposition temperature of the blowing agents (such as TSH, sodium bicarbonates or ammonium bicarbonates) [22][23][24]. Fusion of these porous microbeads is not possible because they are fully cured, and an epoxy binder is needed to act as a matrix and to form the product shape.…”

Section: Gas Phase In Gel Stage  Foamablementioning

confidence: 99%

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Novel Expandable Epoxy Beads and Epoxy Particle Foam

et al. 2022

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Expanded polymeric beads offer the advantage of being able to produce parts with complex geometries through a consolidation process. However, established polymeric beads are made of thermoplastics, deform and melt beyond their temperature services. In this manuscript, a new technique is proposed to fabricate expandable epoxy beads (EEBs), then expand and fuse them to produce epoxy particle foams (EPFs). This technique is called solid-state carbamate foaming technique. For production of EEBs, a mixture of epoxy, carbamate and hardener is prepared and poured into a 10 mL syringe. The mixture is manually extruded into 60 °C water to obtain a cylindric shape. The extrudate is then further cured to obtain an epoxy oligomer behaving rheological tan delta 3 and 2 at 60 °C. The extrudate is cut into pellets to obtain EEBs. The EEBs are then loaded into an aluminum mold and placed in an oven at 160 °C to expand, fuse to obtain EPFs of 212 kg/m3 and 258 kg/m3. The obtained EPFs provide a Tg of 150–154 °C. The fusion boundaries in EPFs are well formed. Thus, the produced EPFs exhibit a compressive modulus of 50–70 MPa, with a torsion storage modulus at 30 °C of 34–56 MPa.

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Section: Gas Phase In Gel Stage  Foamablementioning

confidence: 99%

Section: Gas Phase In Gel Stage  Foamablementioning

confidence: 99%