Application of the thermal energy storage concept to novel epoxy–short carbon fiber composites

Abstract

For the first time, multifunctional epoxy-short carbon fiber reinforced composites suitable for thermal energy storage technology were developed. Paraffin microcapsules (MC) and short carbon fibers (CFs) were added at different relative amounts to an epoxy matrix, and the microstructural and thermomechanical properties of the resulting materials were investigated. Scanning electron microscopy images of the composites showed a uniform distribution of the capsules within the matrix, with a rather good interfacial adhesion, while the increase in the polymer viscosity at elevated CF and MC amounts caused an increase in the void content. Differential scanning calorimetry tests revealed that melting enthalpy values (up to 60 J/g) can be obtained at high MC concentrations. The mixing and thermal curing of the composites did not lead to breakage of the capsules and to the consequent leakage of the paraffin out of the epoxy matrix. The thermal stability of the prepared composites is not negatively affected by the MC addition, and the temperatures at which the thermal degradation process begins were far above the curing or service temperature of the composites. Flexural and impact tests highlighted that the presence of MC reduces the mechanical properties of the samples, while CF positively contributes to retaining the original stiffness and mechanical resistance.

Melt-spun polypropylene filaments containing paraffin microcapsules for multifunctional hybrid yarns and smart thermoregulating thermoplastic composites

“…The DSC thermograms obtained on the filaments collected at 100 m/min are reported in Figure 6a, while Figure 6b shows the first heating scan of the filaments and the compounded samples and reports the melting enthalpy values and the peak temperatures. For all the samples reported in Figure [20,22,23] and elsewhere in the literature [63] for several types of paraffin-based PCMs with similar phase change temperatures, the presence of two or more peaks derive from a sequence of transitions on heating and cooling. The first smaller peak encountered on heating could be related to the solid-solid transition from the crystalline phase to the so-called 'rotator phase', while the second peak could be ascribed to the solid-liquid transition, and the same is observable on cooling.…”

“…However, limited research has been carried out so far to produce such structural TES composites. Some examples are reported in the literature of continuous or discontinuous fiber composites with thermosetting [20][21][22][23][24], thermoplastic [25][26][27][28], or reactive thermoplastic [29,30] matrices. However, the research on continuous-fiber composites with a traditional thermoplastic matrix and TES capability is limited to a single work [25], in which the compaction is performed via film stacking.…”

Structure and Properties of Polysulfone Filled with Modified Twill Weave Carbon Fabrics

“…Polymer composites filled with short CFs are widely used as materials with good mechanical and tribological performance [3,[13][14][15]. The technology of the formation of such composites is relatively cheap and easy [16,17], moreover, they are suitable for production by additive manufacturing [18]. Short CFs can either be chaotically distributed in a polymer matrix or oriented; in the latter, composites show anisotropy in mechanical [18], thermal [18], and tribological [19] properties.…”

Thermal Deformation of PA66/Carbon Powder Composite Made with Fused Deposition Modeling

“…Dorigato et al developed multifunctional epoxy-short carbon-powder-reinforced composites suitable for thermal-energy storage technology for the first time. CF introduction positively was contributed to the material stiffness and strength [14]. Zhu et al presented bending and free-vibration analyses of thin-moderately thick composite plates reinforced by single-walled carbon nanotubes using the finite-element method based on the first-order shear-deformation plate theory.…”