Atomic force microscopy observations of the structural development during the uniaxial stretching of crosslinked low-density polyethylene in partial and fully molten states

2004 ◽  
Vol 42 (12) ◽  
pp. 2228-2237 ◽  
Author(s):  
Yutaka Koike ◽  
Miko Cakmak
2014 ◽  
Vol 804 ◽  
pp. 43-46
Author(s):  
Si Zhao Zhang ◽  
Xue Guang Luo ◽  
Feng Ding ◽  
Ke Li ◽  
Xiao Yan Lin ◽  
...  

Low density polyethylene (LDPE) films added thermal catalyst were investigated at artificial aging time of 0, 10, 20, and 30 days, respectively. The samples obtained were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), gel permeation chromatograph (GPC) and fourier transform infrared spectroscopy (FT-IR). It shows that the surface of film was destroyed via thermocatalytic reactions at lower temperature. In addition, the changes of chemical groups were also observed in the thermocatalytic degradation process. Thus, the validation to the thermocatalytic route has been confirmed over lower temperature excitation. It is hoped that our work may provide a new insight into the degradation of polymeric films at lower temperature.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2811
Author(s):  
Karla Čech Barabaszová ◽  
Sylva Holešová ◽  
Marianna Hundáková ◽  
Alena Kalendová

Materials made from low-density polyethylene (LDPE) in the form of packages or catheters are currently commonly applied medical devices. Antimicrobial LDPE nanocomposite materials with two types of nanofillers, zinc oxide/vermiculite (ZnO/V) and zinc oxide/vermiculite_chlorhexidine (ZnO/V_CH), were prepared by a melt-compounded procedure to enrich their controllable antimicrobial, microstructural, topographical and tribo-mechanical properties. X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR) revealed that the ZnO/V and ZnO/V_CH nanofillers and LDPE interacted well with each other. The influence of the nanofiller concentrations on the LDPE nanocomposite surface changes was studied through scanning electron microscopy (SEM), and the surface topology and roughness were studied using atomic force microscopy (AFM). The effect of the ZnO/V nanofiller on the increase in indentation hardness (HIT) was evaluated by AFM measurements and the Vickers microhardness (HV), which showed that as the concentration of the ZnO/V nanofiller increased, these values decreased. The ZnO/V and ZnO/V_CH nanofillers, regardless of the concentration in the LDPE matrix, slightly increased the average values of the friction coefficient (COF). The abrasion depths of the wear indicated that the LDPE_ZnO/V nanocomposite plates exhibited better wear resistance than LDPE_ZnO/V_CH. Higher HV and HIT microhardness values were measured for both nanofillers than the natural LDPE nanocomposite plate. Very positive antimicrobial activity against S. aureus and P. aeruginosa after 72 h was found for both nanofiller types.


MRS Advances ◽  
2018 ◽  
Vol 3 (44) ◽  
pp. 2705-2712
Author(s):  
Sergei Magonov ◽  
Shijie Wu

AbstractFast imaging in Atomic Force Microscopy enhances the capability of studying phase transitions and surface properties of materials at variable temperatures. This is demonstrated by measurements of several polymers [poly(diethylsiloxane), low-density polyethylene and ethylene-octene copolymer] and bitumen at low (down to -20°C) and high (up to +150°C) temperatures. Monitoring of structural transitions was performed at small and large (up to 40 μm) areas with 1-5°C/min cooling/heating rates. Novel data about dynamics and structural transitions of mesomorphic transitions and crystallization were obtained.


Nano Research ◽  
2015 ◽  
Vol 8 (7) ◽  
pp. 2199-2205 ◽  
Author(s):  
Pauline Vitry ◽  
Eric Bourillot ◽  
Cédric Plassard ◽  
Yvon Lacroute ◽  
Eric Calkins ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1357 ◽  
Author(s):  
Peyman Nikaeen ◽  
Dilip Depan ◽  
Ahmed Khattab

Surface mechanical properties of low-density polyethylene (LDPE) reinforced by carbon nanofibers (CNFs) up to 3% weight load were investigated using nanoindentation (NI). Surface preparation of the nanocomposite was thoroughly investigated and atomic force microscopy (AFM) was used to analyze the surface roughness of the polished surfaces. The dispersion of nanofillers in the LDPE matrix was examined using scanning electron microscopy (SEM). The effect of various penetration loads on the results and scattering of the data points was discussed. It was found by NI results that the addition of 3% weight CNF increased the elastic modulus of LDPE by 59% and its hardness up to 12%. The nano/micro-scale results were compared with macro-scale results obtained by the conventional tensile test as well as the theoretical results calculated by the Halpin-Tsai (HT) model. It was found that the modulus calculated by nanoindentation was twice that obtained by the conventional tensile test which was shown to be in excellent agreement with the HT model. Experimental results indicated that the addition of CNF to LDPE reduced its wear resistance property by reducing the hardness to modulus ratio. SEM micrographs of the semicrystalline microstructure of the CNF/LDPE nanocomposite along with the calculated NI imprints volume were examined to elaborate on how increasing the penetration depth resulted in a reduction of the coefficient of variation of the NI data/more statistically reliable data.


2020 ◽  
pp. 096739112097627
Author(s):  
Dalila Smail ◽  
Saliha Chaoui

In this study low-density polyethylene (LDPE)/thermoplastic starch (TPS)/nanoclay (O-Mt) nanocomposites were prepared by a melt blending process using a Brabender mixer. Dicumyl peroxide (DCP) and nanoclay (O-Mt) were studied to improve interfacial adhesion and to obtain the various desired properties of the nanocomposites. The structure and properties of the materials were studied by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and by tensile and Izod impact tests. X-ray diffraction analysis of the nanocomposites showed that the characteristic peaks of the clay were shifted to the lower angles, indicating an intercalated structure in the presence of dicumyl peroxide (DCP). The TGA curve indicated an improvement in the thermal stability of the materials with the amount of silicate and DCP. The mechanical properties of the materials were improved as a consequence of the increase in phase adhesion which gave an improvement in crystallinity confirmed by DSC. In addition, the impact strength of the modified materials was improved compared to the original materials. A modification of morphology as well as roughness was demonstrated by SEM and AFM.


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