Papers by Keyword: High-Density Polyethylene

Abstract: This article deals with the influence of different doses of Beta radiation on nanomechanical properties of High-density polyethylene (HDPE). These nanomechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. The highest values of nanomechanical properties were reached at radiation dose of 99 kGy, when the nanohardness values increased by about 23%. The purpose of the article is to consider to what extent the irradiation process influences the resulting nanomechanical properties measured by the Depth Sensing Indentation method.

Abstract: Micromechanical changes in the surface layer of High-density polyethylene HDPE modified by beta radiation were measured by instrumented test of nanohardness. The specimens were prepared by injection technology and subjected to radiation doses of 0, 132, 165, 198 kGy. Measurements of nanohardness showed considerable changes of behavior of surface layer in middle as well as high radiation doses with higher values of indentation hardness and stiffness.

Abstract: Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The dynamic mechanical properties and phase structure of PE/MMT nanocomposites at different MMT concentrations (from 0.1 to 1.2 wt %) were studied. The storage modulus of PE/MMT nanocomposites is higher than that of the polymer matrix. And the motions of molecular relaxations and conformational transitions both in non-crystalline and crystalline phases are confined by the strong interactions between polymer and MMT. Otherwise, the spherulite size gradually decreases with the increasing content of MMT.

Abstract: Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The morphology of MMT/MgCl₂/TiCl₄ catalyst and PE/MMT nanocomposites was investigated by scanning electron microscopy (SEM). It can be seen that MMT/MgCl₂/TiCl₄ catalyst remained the original MMT sheet structures and many holes were found in MMT and the morphology of PE/MMT nanocomposites is part of the sheet in the form of existence, as most of the petal structure. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were carried out to characterize all the samples. XRD results reveal that the original basal reflection peak of PEI1 and PEI2 disappears completely and that of PEI3 become very weak. MMT/MgCl₂/TiCl₄ catalyst was finely dispersed in the PE matrix. Instead of being individually dispersed, most layers were found in thin stacks comprising several swollen layers.

Abstract: A superhydrophobic HDPE coating was obtained by a facile but yet effective way. The water contact angle and sliding angle of the superhydrophobic HDPE coating were 156±1.9ºand 3±1.6º, respectively. The HDPE coating was still superhydrophobic contacting with acid, alkali, salt aqueous solutions.

Abstract: Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The isothermal crystallization of PE/MMT nanocomposites at different MMT concentration (from 0.1 wt % to 1.2 wt %) was investigated by differential scanning calorimetry (DSC). The crystallization kinetics shows that the Avrami exponent of PE/MMT nanocomposites is decreased compared with pure PE, which indicates a decrease in the crystal growth dimension. This is attributed to the stems of PE crystals confined in the MMT layers. The crystallization rates of PE/MMT nanocomposites are faster than those of pure PE. However, when the content of MMT increases from 0.1 wt % to 1.2 wt %, the crystallization rate of PE/MMT nanocomposites is decreased.

Abstract: Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The crystallization behavior of PE/MMT nanocomposites at different MMT concentrations (from 0.1 to 1.2 wt %) were investigated by differential scanning calorimetry (DSC). The equilibrium melting points increase by the addition of MMT. The crystallization rates of PE/MMT nanocomposites are faster than those of pure PE. The addition of MMT facilitated the crystallization of PE, with the MMT functioning as a heterogeneous nucleating agent at lower content; at higher concentrations, however, the physical hindrance of the MMT layers to the motion of PE chains retarded the crystallization process.

Abstract: The High-density polyethylene (HDPE) / the ethylene acrylic acid (EAA) - layered double hydroxide (LDH) nanocomposites were prepared by melt blending with EAA)/ LDH master batch; and the structure and properties of this nanocomposite were studied. The results showed that the EAA acted as an effective compatibilizer for the nanocomposites can enhance the interfacial adhesion between LDH and HDPE obviously, promote the dispersion of LDH in the matrix, increase both the tensile strength and toughness of nanocomposites, and improve the thermal stability and delay the onset decomposition temperature of nanocomposites.

Abstract: A new Modifier with Silicon radicals as anchoring group and poly(butyl acrylate) as solvatable chain was synthesized and its effect on the properties of HDPE/Anhydrite composites was investigated in this paper. Fourier transmission infrared spectroscopy (FT-IR) results show that the modifier react on the Anhydrite powder particles surface and the modified Anhydrite powder particles particles. compared with that of HDPE/Anhydrite (filled with same non-modified fraction), The impact strength, tensile strength, bending strength and Young’s modulus of modified HDPE/Anhydrite composites increased about 36.6%, 7.5%, 15.6% and 34% respectively. Based on surface analysis by scanning electron microscope (SEM), the Anhydrite powder particles buried well in HDPE matrix when Anhydrite powder particles was coated with the YB modifier. It was found that Anhydrite powder particles significantly increased the crystallization temperature and crystallization rate of HDPE by differential scanning calorimetry (DSC). At same time, through the X-ray diffraction (XRD) found the addition of the YB modifier modified Anhydrite powder particles can not change the formation of crystal HDPE, but can reduce the crystallite size.

Abstract: Reactive compatibilization between high-density polyethylene(HDPE) and wood-flour was achieved via direct reactive extrusion of glycidyl methacrylate(GMA), initiator, HDPE and wood-flour. Impact rupture surface of the composite was observed by scanning electron microscope(SEM), and its load deformation temperature(HDT) and mechanical properties were tested. Effect of GMA dosage and extrusion temperature on reactive compatibilization of the composite was analysed. The result indicated that the anchoring strength of interface in the composite was obviously strengthened, and its HDT, tensile strength, flexural strength, notched impact strength and elongation at break of the composite were distinctly improved due to the addition of GMA and dicumyl peroxide(DCP). When the composite was extruded at 180°C, the peak values of its HDT, tensile strength, flexural strength, elongation at break and notched impact strength respectively were 84°C, 40Mpa, 45Mpa, 11% and 6.6KJ.m-2, which respectively increased by 17°C, 74%, 36%, 83% and 69% than that of the composite without reactive compatibilization, and when the composite was extruded at 190°C, the peak values of its HDT, tensile strength, flexural strength, elongation at break and notched impact strength respectively were 84°C, 40Mpa, 44Mpa, 11% and 6.6KJ.m-2, which respectively increased by 20°C, 60%, 26%, 83% and 83% than that of the composite without reactive compatibilization. When GMA usage increased, the HDT and mechanical properties of the composite increased first, then descended, and the optimum usage of GMA was 1wt%-3wt%.