scholarly journals LDPE/HDPE/Clay Nanocomposites: Effects of Compatibilizer on the Structure and Dielectric Response

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
B. Zazoum ◽  
E. David ◽  
A. D. Ngô
Keyword(s):  
Dielectric Response ◽  
Interfacial Polarization ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polyethylene Blend ◽  
Twin Screw ◽  
Relaxation Modes

PE/clay nanocomposites were prepared by mixing a commercially available premixed polyethylene/O-MMT masterbatch into a polyethylene blend matrix containing 80 wt% low-density polyethylene and 20 wt% high-density polyethylene with and without anhydride modified polyethylene (PE-MA) as the compatibilizer using a corotating twin-screw extruder. In this study, the effect of nanoclay and compatibilizer on the structure and dielectric response of PE/clay nanocomposites has been investigated. The microstructure of PE/clay nanocomposites was characterized using wide-angle X-ray diffraction (WAXD) and a scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). The dielectric response of neat PE was compared with that of PE/clay nanocomposite with and without the compatibilizer. The XRD and SEM results showed that the PE/O-MMT nanocomposite with the PE-MA compatibilizer was better dispersed. In the nanocomposite materials, two relaxation modes are detected in the dielectric losses. The first relaxation is due to a Maxwell-Wagner-Sillars interfacial polarization, and the second relaxation can be related to dipolar polarization. A relationship between the degree of dispersion and the relaxation ratefmaxof Maxwell-Wagner-Sillars was found and discussed.

Crystallization Behavior and Mechanical Properties of PP/EVA Blends

2014 ◽  
Vol 1033-1034 ◽  
pp. 869-872
Author(s):  
Kun Yan Wang
Keyword(s):  
Mechanical Properties ◽  
Crystallization Behavior ◽  
Ethylene Vinyl Acetate ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Blending Method ◽  
Twin Screw

Polypropylene (PP)/ethylene-vinyl acetate (EVA) blends were prepared using a twin-screw extruder by melt blending method. The influences of the EVA contents in PP/EVA blends on crystallization behavior and mechanical properties were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD results show that the EVA not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. DSC results showed that the melting point and crystallization point decreased when EVA added to the blend. The tensile properties of PP/EVA blend become much better.

Performance of Polypropylene Composites Filled by Calcium Carbonate Whiskers

2011 ◽  
Vol 399-401 ◽  
pp. 415-418
Author(s):  
Qiu Ju Sun ◽  
Gui Zhen Zhao ◽  
Shi Gang Xin ◽  
Shi Wei Wu ◽  
Jie Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Sodium Stearate ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polypropylene Composites ◽  
Twin Screw ◽  
Scanning Electron

Calcium carbonate (CaCO3) whiskers were firstly treated by sodium stearate, and then blended with polypropylene (PP) to prepare the composites by a closely intermeshing co-rotating twin-screw extruder at 200°C. The performance of the composites, such as thermal behavior, microstructure and mechanical properties, were analyzed with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical testing. The results showed that CaCO3 whisker influenced the crystalline behavior of PP phase in the blends because of its intervening. Moreover, thermo-decomposing temperature, tensile and bending strengths of the blends all increased with increasing whisker content. CaCO3 whiskers had good reinforcing and toughening effects on PP.

scholarly journals Correlation between Structure and Dielectric Breakdown in LDPE/HDPE/Clay Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
B. Zazoum ◽  
E. David ◽  
A. D. Ngô
Keyword(s):  
High Density Polyethylene ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Thermomechanical Properties ◽  
Clay Nanocomposites ◽  
Screw Extruder ◽  
Short Term ◽  
Polyethylene Blend ◽  
Twin Screw ◽  
High Voltage Insulation

Cross-linked polyethylene (XLPE) is commonly used in medium/high voltage insulation due to its excellent dielectric properties and acceptable thermomechanical properties. To improve both electrical and thermal properties to a point that would possibly avoid the need for crosslinking, nanoclay fillers can be added to polymer matrix to form nanocomposites materials. In this paper, PE/clay nanocomposites were processed by mixing a commercially available premixed polyethylene/O-MMT masterbatch into a polyethylene blend matrix containing 80 wt% low density polyethylene LDPE and 20 wt% high density polyethylene HDPE with and without compatibilizer using a corotating twin-screw extruder. Various characterization techniques were employed in this paper, including optical microscopy, AFM, TEM, TGA, DMTA, and dielectric breakdown measurements in order to understand the correlation between structure and short-term dielectric breakdown strength.

Tuning of HDPE Properties for 3D Printing

2018 ◽  
Vol 773 ◽  
pp. 67-71 ◽  
Author(s):  
Paweesinee Chatkunakasem ◽  
Panisa Luangjuntawong ◽  
Aphiwat Pongwisuthiruchte ◽  
Chuanchom Aumnate ◽  
Pranut Potiyaraj
Keyword(s):  
3D Printing ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Twin Screw ◽  
Low Crystalline

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

scholarly journals Influence of Processing Type in the Morphology of Membranes Obtained from PA6/MMT Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rodholfo da Silva Barbosa Ferreira ◽  
Caio Henrique do Ó Pereira ◽  
Rene Anisio da Paz ◽  
Amanda Melissa Damião Leite ◽  
Edcleide Maria Araújo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Membrane Morphology ◽  
Twin Screw ◽  
Microscopy Images ◽  
Scanning Electron

The nanocomposites have an extensive use in the current process of membrane preparation, taking into account their unique features as membranes. Thus, the study of nanocomposite processing to obtain membranes is highly important. In this work, Brazilian clay was used (Brasgel PA) for the preparation of polyamide/clay nanocomposite. The nanocomposites were produced in a high rotation homogenizer and in a twin screw extruder. From the nanocomposites and pure polymers processed in the two equipments, membranes were prepared by the immersion-precipitation method, using formic acid as solvent. By X-ray diffraction (XRD), the formation of exfoliated and/or partially exfoliated structures with changes in the crystalline phases of the polyamide was observed. From scanning electron microscopy images, it was observed that the processing clearly influenced the membrane morphology.

Use of Brazilian Clay in Nylon 6 with Different Molecular Weight Nanocomposites

2010 ◽  
Vol 660-661 ◽  
pp. 777-783
Author(s):  
Edcleide Maria Araújo ◽  
Renê Anísio da Paz ◽  
Tomás Jefférson Alves de Mélo ◽  
Amanda Melissa Damião Leite ◽  
Renata Barbosa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nylon 6 ◽  
Layered Silicates ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Torque Rheometry ◽  
Transmission Electron ◽  
Twin Screw ◽  
Different Molecular Weight

The effect of nylon 6 (Ny6) molecular weight on the development of polymer/layered silicates nanocomposites prepared by the melt intercalation technique was studied in this work. The nylon6/organoclay nanocomposites were prepared in the counter-rotational twin screw extruder. The results of torque rheometry showed that the presence of organoclay in the nylon 6 increased the torque. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed exfoliated and/or partially exfoliated structures.

Improvement of toughness properties of polypropylene filled with nanobentonite using stearic acid as interface modifier

2016 ◽  
Vol 51 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Yarazett Hernandez ◽  
Tomas Lozano ◽  
Ana B Morales ◽  
Fabiola Navarro-Pardo ◽  
Pierre G Lafleur ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stearic Acid ◽  
Chemical Interaction ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Surface And Interface ◽  
Acid Incorporation ◽  
Twin Screw ◽  
Physical Interactions

The mechanical properties of polypropylene-bentonite nanocomposites were studied in this work. In this study, stearic acid was used as both a new surface modifier of the nano bentonite and a new interface modifier during the compounding of the nanocomposites with a twin-screw extruder. Three different weight concentrations (1.5 wt.%, 2.5 wt.%, and 5.0 wt.%.) were chosen for each type of nanobentonite compounds. Fourier transform infrared spectroscopy allowed us the possibility to discard any chemical interaction between the nanobentonite and stearic acid. Nevertheless, the physical interactions between both components favored the mechanical properties, resulting in around 150% improvement in the elongation of the nanocomposites containing stearic acid as surface and interface modifier. This can be due to the good intercalation of the nanobentonite platelets as found by wide angle X-ray diffraction and this was further confirmed by scanning electron microscopy, where the fracture surface analyses of these nanocomposites showed the best dispersion and wetting of the nanoplatelets by the polymer matrix. Crystallization behavior was also modified by stearic acid incorporation and the nanocomposites with better dispersion exhibited crystallization temperatures similar to pure polypropylene.

Thermal Conductivity and Crystallography of Polypropylene/Polycarbonate/ Polypropylene-Graft-Maleic Anhydride Polymer Blend

2020 ◽  
Vol 995 ◽  
pp. 56-62
Author(s):  
Muhammad Shafiq Mat Shayuti ◽  
Rahida Wati Sharudin ◽  
Tengku Amran Tengku Mohd ◽  
Putri Nadzrul Faizura Megat Khamaruddin ◽  
Mohamad Zaki Abdullah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Maleic Anhydride ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Reactive Compatibilization ◽  
X Ray ◽  
Medium Range ◽  
Twin Screw ◽  
Standard Tests

The effect of blending polycarbonate (PC) into polypropylene (PP) matrix polymer on thermal conductivity and crystal structure was studied. The blends consisted of 5% to 35% of PC with 5% compatibilizer (polypropylene-graft-maleic anhydride or PP-g-MA), were compounded using twin-screw extruder and shaped into standard tests samples by compression molding. The thermal conductivity values for PP/PC/PP-g-MA blends were ranging from 0.22 – 0.24 W/m.K. When compared to Hanshin – Shtrikman model, the highest difference in the thermal conductivity values was 28.2% shown in 90/5/5 composition. The deviation was due to the exclusion of factors such as PC particulates’ geometry, size, and dispersion in PP matrix. X-ray Diffraction (XRD) test revealed the blends’ structures comprised of medium-range order domains, referring to imperfect crystals with nanoparticles. The locations of peaks in the XRD spectrum also suggest that the pure PP’s monoclinic alpha crystal appeared in all PP/PC/PP-g-MA blends and there was no other crystal obtained in the blends. From the result, the discovered traits of crystal structure displayed influence on the thermal conductivity of the blends. At the same time, reactive compatibilization was suspected to take place at the interface of PP and PC phases when PP-g-MA was introduced.

The Morphology during Extrusion of PA6/PP Blends in the Presence of Nanoclays

2010 ◽  
Vol 636-637 ◽  
pp. 840-845 ◽  
Author(s):  
Maria Ferreira Almeida ◽  
Ana Vera Machado ◽  
José A. Covas
Keyword(s):  
Electron Microscopy ◽  
Dispersed Phase ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Transmission Electron ◽  
Twin Screw ◽  
Oscillatory Rheology ◽  
Pp Blends ◽  
Alkyl Ammonium

The present study investigates the morphology of polyamide (PA6) and polypropylene (PP) blends in the presence of an organoclay during extrusion. Physical PA6 /PP blends and blends of PA6/PP and PP modified with maleic anhydride, both filled with a montmorillonite (MMT) modified alkyl ammonium organoclay, were prepared in a modular co-rotating twin screw extruder. Samples were collected along the extruder and analyzed by X-ray diffraction (XRD), oscillatory rheology, and scanning and transmission electron microscopy (SEM and TEM, respectively). Intercalation and some degree of clay exfoliation seem to have been achieved. Generally, the presence of the organoclay yields a finer dispersed phase along the extruder.

scholarly journals Influence of Compatibilizer and Processing Conditions on Morphology, Mechanical Properties, and Deformation Mechanism of PP/Clay Nanocomposite

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
B. Akbari ◽  
R. Bagheri
Keyword(s):  
Mechanical Properties ◽  
Deformation Mechanism ◽  
Feeding Rate ◽  
Processing Conditions ◽  
Feeding System ◽  
Rotor Speed ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Twin Screw

Polypropylene/montmorillonite nanocomposite was prepared by melt intercalation method using a twin-screw extruder with starve feeding system in this paper. The effects of compatibilizer, extruder rotor speed and feeding rate on properties of nanocomposite were investigated. Structure, tensile, and impact properties and deformation mechanism of the compounds were studied. For investigation of structure and deformation mechanisms, X-ray diffraction (XRD) and transmission optical microscopy (TOM) techniques were utilized, respectively. The results illustrate that introduction of the compatibilizer and also variation of the processing conditions affect structure and mechanical properties of nanocomposite.

Sign in / Sign up

Export Citation Format

Share Document