Studies of Mechanical Properties and Melting Behaviour of Foamed and Crosslinked LDPE/PP Blends

2002 ◽  
Vol 21 (6) ◽  
pp. 431-443 ◽  
Author(s):  
George Kotzev
Keyword(s):  
Mechanical Properties ◽  
Melting Behaviour ◽  
Crosslinking Degree ◽  
Foaming Agent ◽  
Pp Blends ◽  
Insoluble Portion

Foamed crosslinked specimens of LDPE/PP blends produced by RIM process were examined. A crosslinking system containing 2,5-dimethyl-2,5-di(tert.-butylperoxy)hexane as an initiator and hydroquinone as a coagent was used. Azodicarbonamide was applied as a foaming agent. The crosslinking degree was evaluated by insoluble portion of the blends. An improvement of the mechanical properties due to crosslinking mainly in the LDPE phase as well as crosslinking between polyethylene and polypropylene on their interface was observed. Melting behaviour of the blends studied by DSC shows that both the initiator and the coagent cause opposite effects on temperatures and enthalpies of melting.

scholarly journals Improving Rheological and Mechanical Properties of Various Virgin and Recycled Polypropylenes by Blending with Long-Chain Branched Polypropylene

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1137
Author(s):  
Sascha Stanic ◽  
Thomas Koch ◽  
Klaus Schmid ◽  
Simone Knaus ◽  
Vasiliki-Maria Archodoulaki
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Test ◽  
Reactive Extrusion ◽  
Original Material ◽  
Melt Flow Rate ◽  
Single Screw Extruder ◽  
Pp Blends ◽  
The Impact ◽  
Long Chain

Blends of two long-chain branched polypropylenes (LCB-PP) and five linear polypropylenes (L-PP) were prepared in a single screw extruder at 240 °C. The two LCB-PPs were self-created via reactive extrusion at 180 °C by using dimyristyl peroxydicarbonate (PODIC C126) and dilauroyl peroxide (LP) as peroxides. For blending two virgin and three recycled PPs like coffee caps, yoghurt cups and buckets with different melt flow rate (MFR) values were used. The influence of using blends was assessed by investigating the rheological (dynamic and extensional rheology) and mechanical properties (tensile test and impact tensile test). The dynamic rheology indicated that the molecular weight as well as the molecular weight distribution could be increased or broadened. Also the melt strength behavior could be improved by using the two peroxide modified LCB-PP blends on the basis of PODIC C126 or PEROXAN LP (dilauroyl peroxide). In addition, the mechanical properties were consistently enhanced or at least kept constant compared to the original material. In particular, the impact tensile strength but also the elongation at break could be increased considerably. This study showed that the blending of LCB-PP can increase the investigated properties and represents a promising option, especially when using recycled PP, which demonstrates a real “up-cycling” process.

scholarly journals A new expansion material used for roof-contacted filling based on smelting slag

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua Na ◽  
Guocheng Lv ◽  
Lijuan Wang ◽  
Libing Liao ◽  
Dan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Peroxide ◽  
Compressive Strength ◽  
Sodium Silicate ◽  
Utilization Rate ◽  
Ammonium Bromide ◽  
Foaming Agent ◽  
Copper Nickel ◽  
Smelting Slag ◽  
Nickel Smelting

AbstractThe improper handling of smelting slag will seriously pollute the environment, and the unfilled roof of the goaf of the mine will threaten the safety of the mine. Expansion materials have attracted more and more attention because of their excellent properties. In this paper, copper-nickel smelting slag that has some active ingredients of gelling is used instead of traditional aggregate and some part of cement in order to reduce its pollution to the environment and its costs. For safety reasons, hydrogen peroxide was chosen as the foaming agent. Sodium silicate and hexadecyl trimethyl ammonium bromide (CTAB) are used as additives. Our results showed that after 28 days of curing, the material has better mechanical properties and the early compressive strength of the material was enhanced by sodium silicate. The efficiency of foaming was improved by CTAB. It also proves that copper–nickel smelting slag can be used in expansion material. At the same time, the utilization rate of the copper–nickel smelting slag of this formula can reach 70%, reduce its pollution to the environment.

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

scholarly journals The effect of foaming agent on mechanical and physical properties of Polypropylene

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
SEDEF CAKIR 1 ◽  
MUHAMMED AYCICEK 1 ◽  
EDIZ ALTUN 2 ◽  
Akin Akinci 1
Keyword(s):  
Mechanical Properties ◽  
Cell Density ◽  
Cell Morphology ◽  
Injection Pressure ◽  
Skin Layer ◽  
Polymer Materials ◽  
Cell Diameter ◽  
Melt Temperature ◽  
Foaming Agent ◽  
Foaming Agents

In this study, Polypropylene (PP) foam materials were used with injection parameters such as melting, molding and injection temperatures. To produce foam materials, chemical foaming agents were used, and added to polymer materials as 1wt.%, 1.5wt.%, 2wt.%, 2.5wt.%, 3wt.%. The mechanical properties of foam samples were determined based on the parameters. Cell morphology characterization such as cell diameter, cell count, skin layer thickness and cell density, and mechanical properties such as tensile and impact strength of polymer foams were examined.Generally, the closed-cell foam structure was obtained. The most important parameters affecting the cell morphology have been injection pressure, melt temperature and amount of foaming agent. With increasing the amount of foaming agent, cell density increased, foam density and mechanical properties decreased.

Correlation between Zirconium Addition and Compressive Properties of AZ31 Mg Alloy Foams

2011 ◽  
Vol 121-126 ◽  
pp. 75-79
Author(s):  
Bo Young Hur ◽  
Rui Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Mg Alloy ◽  
Compressive Properties ◽  
Absorption Properties ◽  
Compression Behavior ◽  
Foaming Agent ◽  
Az31 Mg Alloy ◽  
Absorption Characteristics ◽  
Zirconium Addition

The compressive behaviors of AZ31-Zr foams using Ca particles as thickening agent and CaCO3 powder as foaming agent were investigated in this study. The porosity was about 48.7%~72.9%, pore size was between 0.43~0.97 mm, and homogenous pore structures were obtained. Mechanical properties of AZ31 Mg alloy foams were investigated by means of UTM. The cellular AZ31 Mg foams possess superior comprehensive mechanical properties. The energy absorption characteristics and the effects of compression behavior on the energy absorption properties for the cellular AZ31 Mg foams have been investigated and discussed. The results show that with the addition of Zr, the Mg alloy foam has the highest energy absorption value of 16.26 MJ/m3 and the hardness value of 81.8 HV, which is much higher than that of the foams fabricated without Zr.

Multifunctional foaming agent to prepare aluminum foam with enhanced mechanical properties

2018 ◽  
Vol 5 (3) ◽  
pp. 036529
Author(s):  
Xun Li ◽  
Ying Liu ◽  
Jinwen Ye ◽  
Xuguang An ◽  
Huaying Ran
Keyword(s):  
Mechanical Properties ◽  
Aluminum Foam ◽  
Foaming Agent

scholarly journals Compatibilization of Polypropylene/Polyamide 6 Blend Fibers Using Photo-Oxidized Polypropylene

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 81 ◽  
Author(s):  
Francesco La Mantia ◽  
Manuela Ceraulo ◽  
Maria Mistretta ◽  
Luigi Botta ◽  
Marco Morreale
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Morphological Changes ◽  
Elongational Flow ◽  
Polyamide 6 ◽  
Flow Conditions ◽  
Polyolefin Blends ◽  
Pp Blends ◽  
Oxidized Polypropylene

The use of polyamide/polyolefin blends has gained importance and concern for years, but they also show some issues to be adequately addressed, such as the incompatibility between the two components. This is usually overcome by using suitable compatibilizers, typically based on functionalized polyolefins. However, there is only little information about the use of a degraded polyolefins to induce compatibilization. This is even truer, as far as polyamide 6/polypropylene (PA6/PP) blends are concerned. In this work, compatibilization of PA6/PP blends by using small amounts of photo-oxidized PP was investigated; furthermore, the effects due to the presence of the photo-oxidized PP were studied also in relationship to the spinning operation, where the existence of the non-isothermal elongational flow can lead to significant, further morphological changes. It was found that isotropic samples showed significant enhancements of the tensile properties upon adding the photo-oxidized PP. Under non-isothermal elongational flow conditions, the presence of the photo-oxidized PP was particularly effective in improving the mechanical properties in comparison to the uncompatibilized blend fibers. Furthermore, an important result was found: The elongational-flow processing allowed obtaining anisotropic samples where the improvements of the properties, in comparison to the isotropic samples, were similar to those achieved by using a compatibilizer.

The Effect of Polyethylene-Octene Elastomer on the Morphological and Mechanical Properties of Polyamide 6/Polypropylene Nanocomposites

2005 ◽  
Vol 13 (8) ◽  
pp. 795-805 ◽  
Author(s):  
M.U. Wahit ◽  
A. Hassan ◽  
Z.A. Mohd Ishak ◽  
A. Abu Bakar
Keyword(s):  
Mechanical Properties ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Compounding ◽  
Modified Montmorillonite ◽  
Polypropylene Nanocomposites ◽  
Rubber Toughened ◽  
Izod Impact ◽  
Pp Blends

Rubber-toughened nanocomposites (RTNC) consisting of ternary blends of polyamide 6 (PA6), polypropylene (PP) and polyethylene-octene elastomer (POE) containing 4 wt% of organophilic modified montmorillonite were produced by melt compounding followed by injection moulding. The blend composition was kept constant (PA6/PP=70/30 parts by weight) while the POE content was varied between 5 and 20 wt%. Maleated PP (PP-g-MA) was used as compatibilizer. The morphology of the RTNC was studied by scanning electron microscopy and X-ray diffraction (XRD). The mechanical properties of RTNC were studied through tensile, flexural, Izod impact and fracture toughness properties. While the tensile and flexural properties were found to decrease with the increasing concentration of POE, the toughness was significantly enhanced as compared to the neat PA6/PP blends. In general, the blends containing 10-15 wt% of POE had the best balance of stiffness, strength and toughness. The addition of 30 wt% of PP in the PA6 matrix improved the compatibility between PA6 and the rubber phase. XRD established that the organoclay was well dispersed (exfoliated) and preferentially embedded in the PA6 phase.

scholarly journals Expansion volume of alkali activated foamed cork composites from tungsten mining mud waste with aluminium

2019 ◽  
Vol 274 ◽  
pp. 03002
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes ◽  
Haroon Ihsan ◽  
John Pickstone ◽  
Nuno Estrada
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Porous Structures ◽  
Expansion Process ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

Several mixes of alkali activated foams from tungsten mud waste (MW), grounded glass (GG) and metakaolin (MK) were developed incorporating expanded granulated cork (EGC). This study presents preliminary results of the expansion process obtained with the addition of aluminium (AL) powder as a foaming agent. 0.3 wt.%, 0.4 wt.% to 0.5wt.% of AL powder were added to the alkali activated matrix. The physical and mechanical properties of the obtained foams, the effects of the type and amount of the foaming agent added are presented and discussed. Highly porous structures were obtained, with overall expansion up to 68.2% when the AL powder was added. The size and distribution of pores are shown. The compressive strength of foams in the case of highly porous structures achieved of 1.2 MPa for the samples containing 0.5 wt.% of AL powder. Mechanical and thermal properties of the cured structure are good and can therefore be used for applications in acoustic panels and lightweight prefabricated components for thermal insulation purposes.

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