Prediction of the radiation term in the thermal conductivity of crosslinked closed cell polyolefin foams

Thermal conductivity of open‐cell polyolefin foams

“…Solid conduction accounts for 28% and radiation for approximately a 16%. All these values are similar to those found for closed‐cell foams of similar compositions 8–10…”

“…Table 1 shows the foams density and average cell sizes of the foams under study, density ranged between 23 and 64 kg/m 3 which means porosities in the range of 97–93% and cell sizes between 630 and 3300 μm, these cell size are much higher than those previously measured in closed‐cell crosslinked polyolefin foams 8–10…”

“…From the previous description it seems that the structure of the materials under study has several characteristics of the closed‐cell material (presence of faces in the cells) and several other of the open‐cell material (the gas phase is continuous). In fact the values for f s were between 0.5 and 0.6 (Table 1), value in between that for the closed‐cell polyolefin foams (around 0.2),8–10 and that for the open‐cell PU ( f s ≈ 1)…”

μCT-Based Analysis of the Solid Phase in Foams: Cell Wall Corrugation and other Microscopic Features

“…It is difficult to estimate a value for the error of this 3D methodology considering the unclear frontier separating the strut from the wall within a continuous structure. On the other hand, there is no exact reference method for comparison although the values are in congruence with the literature for these materials (Almanza et al, 2004; Rodíguez-Pérez et al, 2008). In fact, alternative methodologies should be less accurate (Kuhn et al, 1992; Glicksman, 1994).…”

Research of Ferric Ion Regulation on a Polyimide/C-MXene Microcellular Composite Film

“…25 When the FeCl 3 content was low at 0.2−0.8 wt %, the thermal conductivity was mainly effected by the cellular size. In detail, with the FeCl 3 content increasing, the cellular size decreased and the thermal conductivity also decreased; 26,27 when the FeCl 3 content improved to 1.2−1.6 wt %, ferric ions became the main effect for thermal conductivity increasing, which is because of the enough ferric ions that easily connected with each other and formed the network structure, which were beneficial for thermal conduction. 28 Figure 5b shows the tensile strength and Young's modulus of the polyimide/C-MXene microcellular composite film with different FeCl 3 contents.…”