Optimization of the Physical Properties of HDPE/PU Blends through Improved Compatibility and Electron Beam Crosslinking

Abstract

Polymer blending is a method in which polymers with different properties are mixed so that each advantage appears in one polymer blend. Improved thermal and mechanical properties of blends can be prepared by blending with high-density polyethylene (HDPE) of a non-polar polymer and polyurethane (PU) of a polar polymer. However, a compatibilizer is required because it has the disadvantage that blending has low miscibility due to the different phases. In this study, HDPE/PU blends with new and excellent physical properties were developed through optimal composition with improved compatibility between the HDPE and PU. In addition, the effects of improving the physical properties through electron-beam crosslinking were confirmed. In general, a crosslinking structure of HDPE is formed by electron beam irradiation to increase its thermal stability and strength, but its elongation is rapidly decreased. In particular, the elongation of HDPE irradiated at 100 kGy was about 110%, which was decreased about five times compared to unirradiated HDPE (510%). However, the HDPE/PU blend with improved compatibility (PU 30) showed an elongation of about 450% while maintaining excellent strength (22.5 MPa), which was increased by about four times compared to the HDPE irradiated at 100 kGy. In particular, the thermal stability of PU 30 irradiated at 100 kGy at a high temperature (180 °C) was improved more than six times compared to the HDPE. Therefore, it is possible to develop HDPE/PU blends with new and excellent physical properties by improving compatibility and using electron beam crosslinking technology.

The Modification of Useful Injection-Molded Parts’ Properties Induced Using High-Energy Radiation

“…The actuator of these changes was the cross-linking process, which resulted in the creation of free radicals (breakup of C-H bonds) that subsequently recombined into a spatial network due to the linking of two free radicals together (C-C bond) with neighboring chains. As a result, mechanical properties were changed, which corresponds with the conclusions of other authors [ 18 , 24 , 25 , 26 ]. In the case of some polymers, an addition of a polyfunctional monomer is necessary to increase the initiation and recombination tendency of its radicals.…”

“…However, this universality is strongly dependent on the absorbed radiation dose, especially the ratio between both coexisting processes, i.e., cross-linking and degradation (oxidation). Up to now, many important studies have been written on the topic of the influence of high-energy radiation on the useful properties of polymer materials, e.g., studies of Holik, Danek, Manas et al [33,34] and other authors [5,[18][19][20][21][22][23][24][25][26][27][28][29]. Nevertheless, the aforementioned correlation between the absorbed radiation dose and the required surface and mechanical properties has not yet been comprehensively investigated.…”

Long-term antifouling surfaces for urinary catheters

“…Various ether-bearing precursors have been explored for this purpose. For instance, ethylene glycol dimethyl ether 30 and tetraglyme 31 stand out as some of the most commonly used precursors in plasma-polymerization processes.…”

Structural Insights into LDPE/UHMWPE Blends Processed by γ-Irradiation

“…The availability of polyethylene to generate high-performance blends has been comprehensively studied [ 26 , 27 ]. Accordingly, some procedures through which the compatibilization of blending components makes possible the achievement of intimate phase interpenetration during radiation processing have been published [ 28 , 29 , 30 ]. The structure and morphology of various sorts of polyethylene are the favorable features by which polyethylene is modified due to the action of radiolysis-free radicals and their contribution to forming intermolecular bridges [ 31 ].…”