Structure and properties of phase‐change materials based on high‐density polyethylene, hard Fischer–Tropsch paraffin wax, and wood flour

Abstract

Phase‐change materials based on high‐density polyethylene (HDPE), a hard Fischer–Tropsch paraffin wax (H1 wax), and alkali‐treated wood flour (WF) were investigated. The blends and composites were prepared by melt‐mixing. They were characterized in terms of their morphology as well as thermal, mechanical, thermomechanical, and water absorption properties. Although the scanning electron microscopy micrographs showed some evidence of intimate contact between WF and the HDPE matrix, there were poor filler dispersion and interfacial adhesion. The percentage miscibility of H1 wax in HDPE seems to have decreased with increasing wax content in the blends. A fairly strong affinity between the WF and H1 wax was noticed. There was plasticization of the HDPE matrix by the wax as well as inhomogeneity and uneven wax dispersion within the polymer matrix. The presence of H1 wax and WF influenced the crystallization behavior of the HDPE matrix. The incorporation of wax reduced the thermal stability of the blends and composites, but stabilized the WF. The H1 wax and WF differently influenced the viscoelastic properties of the HDPE matrix. In contrast to the blends where the tensile properties improved in the presence of wax, the composites showed poorer properties. An increase in wax content resulted in a decrease in water uptake by the composites. POLYM. COMPOS., © 2011 Society of Plastics Engineers.

Extruded versus solvent cast blends of poly(vinyl alcohol‐co‐ethylene) and biopolymers isolated from municipal biowaste

“…For PVOH/starch composites lower melting temperature and lower enthalpy than for pure PVOH has been observed . The decrease in melting temperature coupled to the increase in specific melting enthalpy has been reported for polyolefin/wax and/or natural fibers blends upon increasing the filler content in the blend . In this case, the increase of the blend enthalpy was attributed to several reasons such as (i) the higher specific enthalpy of the added filler compared with the polyolefin (polypropylene and polyethylene) matrix, and (ii) partial miscibility or co‐crystallization of the added filler with the polyolefin matrix.…”

Thermal, structural and morphological properties of High Density Polyethylene matrix composites reinforced with submicron agro silica particles and Titania particles

“…These cavities as illustrated by the arrows in Fig. 8(e-g) are produced due to the debonding of the silica particles [18]. In general, an increased content of SiO 2 would lead to a larger agglomerates because of the formation of hydrogen bonds among the abundant hydroxyl groups and adsorbed water on their surface and hence greater probability of debonding due to the poor interfacial adhesion [15,19] as there is not enough time for inducing matrix yielding after excessive particles debonding, the matrix beside the cavities seems to be rather flat; this coincides with the reduction of toughness of SiO 2 /HDPE composites at high SiO 2 loading.…”

Selected thermal properties of polyethylene waxes

“…in cabling and electrotechnical industry, rubber industry, PVC processing, for production of dye concentrates, printer's inks, in lacquer and textile industry, for bitumen and paraffin modification, hydrophobic treatment of wooden surfaces, in production of fertilizers [5][6][7][8]. The possibility of wax use is determined by its thermal properties, among other things.…”