scholarly journals A Study of the Mechanical Behavior and Crystal Structure of UHMWPE/HDPE Blend Fibers Prepared by Melt Spinning

2018 ◽  
Vol 13 (3) ◽  
pp. 155892501801300
Author(s):  
Fei Wang ◽  
Lichao Liu ◽  
Ping Xue ◽  
Mingyin Jia ◽  
Hua Sun
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Mechanical Behavior ◽  
Melt Spinning ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Melt Flow Index ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Spinning Process

Ultrahigh molecular weight polyethylene (UHMWPE) and high-density polyethylene (HDPE) blend fibers with the highest tensile strength of 1.13 GPa were prepared by a melt spinning process. The crystal structure and mechanical behavior of the as-spun filaments and fibers were studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), sound velocity orientation test and tensile strength test. The results suggested that the degree of molecular chain orientation, crystallinity and mechanical properties of the blend fibers were improved by blending with the low melt flow index (MFI) HDPE. The crystal grains of low MFI HDPE blend fibers that were formed by more highly oriented molecular chains could be stretched more effectively in the drawing direction, and the improved mechanical properties were due to the more regular and compact crystal structure.

scholarly journals Halloysite Nanotubes and Silane-Treated Alumina Trihydrate Hybrid Flame Retardant System for High-Performance Cable Insulation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2134
Author(s):  
Sandra Paszkiewicz ◽  
Izabela Irska ◽  
Iman Taraghi ◽  
Elżbieta Piesowicz ◽  
Jakub Sieminski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Blend ◽  
Hybrid System ◽  
Reference Sample ◽  
Melt Flow Index ◽  
Halloysite Nanotubes ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index ◽  
Alumina Trihydrate

The effect of the presence of halloysite nanotubes (HNTs) and silane-treated alumina trihydrate (ATH-sil) nanofillers on the mechanical, thermal, and flame retardancy properties of ethylene-vinyl acetate (EVA) copolymer/low-density polyethylene (LDPE) blends was investigated. Different weight percentages of HNT and ATH-sil nanoparticles, as well as the hybrid system of those nanofillers, were melt mixed with the polymer blend (reference sample) using a twin-screw extruder. The morphology of the nanoparticles and polymer compositions was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanical properties, hardness, water absorption, and melt flow index (MFI) of the compositions were assessed. The tensile strength increases as a function of the amount of HNT nanofiller; however, the elongation at break decreases. In the case of the hybrid system of nanofillers, the compositions showed superior mechanical properties. The thermal properties of the reference sample and those of the corresponding sample with nanofiller blends were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Two peaks were observed in the melting and crystallization temperatures. This shows that the EVA/LDPE is an immiscible polymer blend. The thermal stability of the blends was improved by the presence of HNTs and ATH-sil nanoparticles. Thermal degradation temperatures were shifted to higher values by the presence of hybrid nanofillers. Finally, the flammability of the compositions was assessed. Flammability as reflected by the limiting oxygen index (OI) was increased by the presence of HNT and ATH-sil nanofiller and a hybrid system of the nanoparticles.

scholarly journals Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1242
Author(s):  
Olga Mysiukiewicz ◽  
Paulina Kosmela ◽  
Mateusz Barczewski ◽  
Aleksander Hejna
Keyword(s):  
Mechanical Properties ◽  
Melt Flow Index ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Metal Composites ◽  
Pre Treatment ◽  
The Impact ◽  
Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

Comparison of Melt Flow and Mechanical Properties of Rice Husk and Kenaf Hybrid Composites

2013 ◽  
Vol 701 ◽  
pp. 42-46 ◽  
Author(s):  
Abd Aziz Noor Zuhaira ◽  
Rahmah Mohamed
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Rice Husk ◽  
Hybrid Composites ◽  
Natural Fibers ◽  
Melt Flow Index ◽  
Silica Content ◽  
Flow Index ◽  
Melt Flow

This research is to identify the difference in melt flow and mechanical properties in hybrid composites between kenaf and rice husk that each of the filler was compounded with composite material of calcium carbonate (CaCO3) and high density polyethylene (HDPE) in different loading amount. Different filler loading up to 30 parts of kenaf fibers and rice husk particulate were mixed with the fixed 30% amount of CaCO3. Compounded hybrid composite were prepared and tested for melt flow index, tensile and impact strength. Addition of both fillers had decreased melt flow index (MFI). MFI of rice husk/CaCO3 was higher than kenaf/CaCO3 in HDPE composites. Tensile strength, elongation at break and impact properties of both hybrid composites had decreased with increasing filler content. Tensile strength of kenaf/CaCO3 was higher than rice husk/CaCO3 due to intrinsic fiber structure of kenaf which has some reinforcing effect compared to rice husk. While, impact strength of rice husk/CaCO3 was improved with addition of filler but drastically decrease as the rice husk content were increased up to 30% due to high silica content in rice husk. The Youngs Modulus was increased with addition of natural fibers in CaCO3/HDPE composite.

Mixtures of Recycled Milk Pouches with a Virgin LDPE-LLDPE Blend

2005 ◽  
Vol 21 (3) ◽  
pp. 219-230 ◽  
Author(s):  
Arup Choudhury ◽  
Mandira Mukherjee ◽  
Basudam Adhikari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rheological Properties ◽  
Melt Flow Index ◽  
Flow Index ◽  
Thermal And Mechanical Properties ◽  
Melt Flow ◽  
Recycled Materials ◽  
Elongation At Break

The present investigation deals with the viability of the use of recycled milk pouch material, which is a 50:50 mixture of LDPE and LLDPE, and the scope for improvement of its properties by combining it with virgin LDPE-LLDPE (50/50). Melt flow index (MFI), rheological properties, thermal and mechanical properties of the pure materials and their formulated blends containing recycled milk pouches were studied. The properties of the recycled materials were not as satisfactory as those of the corresponding virgin materials. But a significant improvement in viscosity, crystallinity, tensile strength and elongation at break of the recycled LDPE-LLDPE material was achieved by blending it with the corresponding virgin LDPE-LLDPE blend.

A green method to fabricate porous polypropylene fibers: development toward textile products and mechanical evaluation

2019 ◽  
Vol 90 (5-6) ◽  
pp. 547-560 ◽  
Author(s):  
Xiang Yan ◽  
Aurélie Cayla ◽  
Fabien Salaün ◽  
Eric Devaux ◽  
Pengqing Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Melt Spinning ◽  
Weight Ratio ◽  
Mechanical Analysis ◽  
Water Soluble ◽  
Drawing Ratio ◽  
Scanning Calorimetry ◽  
Excellent Thermal Stability ◽  
Crystallization Behaviors ◽  
Spinning Process

In this study, a series of immiscible polymer blend fibers with polypropylene (PP) and polyvinyl alcohol (PVA) was obtained by a melt spinning process, and two different draw ratios were attempted. Efforts were made to obtain the porous PP fibers by removing the water-soluble PVA phase. The thermal properties of the blends were tested by thermogravimetric analysis and differential scanning calorimetry. The blends showed excellent thermal stability and differentiated fractionated crystallization behaviors of PP. The melt flow indexes of the blends were evaluated, exhibiting a higher fluidity than that of the neat polymers. Among the possible candidates for the spinning process, only the PP70–PVA30 had suitable spinnability, for which the draw ratio reached 3. The morphology of the fibers was investigated by selective extraction experiment and scanning electron microscopy, as well as wide-angle X-ray diffraction. The biphasic morphology and the crystallization behaviors varied according to the PVA content. Furthermore, the mechanical properties of the multifilament fibers were studied via tensile testing and dynamical mechanical analysis. The 70/30 weight ratio (PP/PVA) was the most suitable for producing biphasic fibers with a high degree of accessibility in PVA and mechanical properties that increase with the increase in the drawing ratio. The feasibility of fabric knitting was checked, and the mechanical properties and air permeability of the obtained textile structure were also evaluated.

scholarly journals The Influence of the Accelerated Aging Conditions on the Properties of Polyolefin Geogrids Used for Landfill Slope Reinforcement

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1874
Author(s):  
Agnieszka Kiersnowska ◽  
Wojciech Fabianowski ◽  
Eugeniusz Koda
Keyword(s):  
Mechanical Properties ◽  
Relative Elongation ◽  
Oxidative Degradation ◽  
Accelerated Aging ◽  
Melt Flow Index ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Oxidation Induction Time ◽  
Aging Test ◽  
Different Temperatures

Polyolefin geosynthetics are susceptible to oxidative degradation, which in turn leads to diminished mechanical properties in geotechnical constructions. When using these materials, it is extremely important to determine their durability over time in particularly aggressive conditions. In order to prolong the life of a geosynthetic material, antioxidants are added during the manufacturing process. The function of antioxidants is to prevent polymer oxidation reaction in time. As the antioxidant content is depleted, the polymer becomes less protected towards oxidative attacks. This article describes the aging process of uniaxial (high density polyethylene) HDPE geogrids under the influence of chemical and environmental factors. Evaluations of accelerated aging test of the uniaxial HDPE geogrids were incubated in simulated landfill conditions for a period of 12 months. Three temperatures (25 °C, 45 °C, and 75 °C) were selected for carrying out the aging experiments in aqueous solutions mimicking landfill conditions. The changes observed by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and melt flow index (MFI) correlate with the mechanical properties of the aged geogrid. No significant changes in the FTIR and MFI were observed over the 12 months of accelerated aging tests at none of the three different temperatures. The oxidation induction time (OIT) test showed no antioxidant remaining in the geogrid following eight months of aging test at 75 °C. No significant changes in the influence of accelerated aging tests on the average relative elongation at 25 °C and 45 °C of the tested material were observed. Accelerated aging tests at 75 °C showed that the mean elongation of 12.12% for the sample not subjected to accelerated aging tests (new sample) increased to 19.32% (after 12 months of incubation).

scholarly journals Application of Physical Methods for the Detection of a Thermally Degraded Recycled Material in Plastic Parts Made of Polypropylene Copolymer

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 552
Author(s):  
Luboš Běhálek ◽  
Jozef Dobránsky ◽  
Martin Pollák ◽  
Martin Borůvka ◽  
Pavel Brdlík
Keyword(s):  
Mechanical Properties ◽  
Volume Flow Rate ◽  
Melt Flow Index ◽  
Bending Test ◽  
Flow Index ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Physical Methods ◽  
Plastic Parts ◽  
Recycled Material

The paper deals with the possibility of applying physical methods to detect a thermally degraded recycled material in plastic parts made of polypropylene. Standard methods of evaluating the mechanical properties of the material under static tensile and bending stress, as well as under dynamic impact stress using the Charpy method, were used for the experimental measurements. The rheological properties of materials were monitored using a method involving measuring the melt flow index, while their thermal properties and oxidative stability were monitored using differential scanning calorimetry. Based on the methods used, it can be clearly stated that the most suitable technique for detecting thermally degraded recycled material in polypropylene is the method involving establishing the melt flow index. The bending test seems to be the most suitable method for detecting recycled material by measuring the material’s mechanical properties. Similarly to the melt volume flow rate (MVR) method, it was possible to unambiguously detect the presence of even a small amount of recycled material in the whole from measuring the material’s bending properties. It is clear from the results that in the short term, there may be no change in the useful properties of the parts, but in the long term the presence of degraded recycled material will have adverse consequences on their lifespan.

scholarly journals РОЗРОБКА НАПОВНЕНИХ ПОЛІОЛЕФІНОВИХ КОМПОЗИЦІЙ ДЛЯ ЛИТТЄВИХ ВИРОБІВ

2020 ◽  
Vol 140 (6) ◽  
pp. 95-103
Author(s):  
С. В. Сайтарли ◽  
В. П. Плаван ◽  
Л. С. Дзюбенко ◽  
О. С. Керенівський ◽  
Д. М. Євдокименко
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Injection Molding ◽  
Frost Resistance ◽  
Melt Flow Index ◽  
Production Costs ◽  
Flow Index ◽  
Melt Flow ◽  
Polyolefin Elastomer

To develop filled polymer compositions based on polypropylene with different contents of calcite concentrate as a filler and the newest polyolefin elastomer as a modifier; to define the influence of the compositions on their rheological and physico-mechanical properties for production injection molded goods. The values of viscosity, melt flow index, tensile strength, elongation, and impact strength and frost resistance of the compositions depending on their composition are determined by standard methods. The influence of calcite concentrate as a filler and polyolefin elastomer as a modifier on the rheological and mechanical properties of compositions has been determined. With an increase in the amount of filler the physical and mechanical properties of the filled compositions are reduce that is offset by introducing the newest polyolefin elastomer as a modifier in amount of 5 wt. %. Addition of 5 wt. % of polyolefin elastomer in the filled composition gives them frost resistance, wherein the impact strength is higher than for compositions without the modifier even after freezing for 30 days at -18°С. It has been determined that adding of the filler does not increase the viscosity of the compositions, which contradicts the traditional behavior of filled systems. The addition of 5 wt. % of polyolefin elastomer to the filled compositions with calcite concentrate up to 20 wt.% does not change the tensile strength of the compositions which is 24 MPa, but increases elongation by 2 times, impact strength by an average of 8,5 % and frost resistance after freezing compositions at -18 °C for 30 days by an average of 12,6 %. The research results of rheological and physic-mechanical properties allow choosing the rational composition to achieve the desired characteristics of the polymer material for production goods by injection molding. Melt flow index of the compositions increases with increasing amount of filler to 50 wt. %. which does not increase the production costs of the injection molding process in comparison with unfilled compositions.

Electrical and mechanical properties of phenoxy/multiwalled carbon nanotubes multifilament yarn processed by melt spinning

2012 ◽  
Vol 82 (20) ◽  
pp. 2106-2115 ◽  
Author(s):  
Jonas Bouchard ◽  
Aurélie Cayla ◽  
Vincent Lutz ◽  
Christine Campagne ◽  
Eric Devaux
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Melt Spinning ◽  
Rheological Behaviour ◽  
Melt Flow Index ◽  
Flow Index ◽  
Electrical Measurements ◽  
Multiwalled Carbon ◽  
Multifilament Yarn

Nanocomposites based on Poly ((hydroxy ether) of bisphenol A) (Phenoxy) filled with multiwalled carbon nanotubes has been prepared by extrusion. Rheological behaviour and thermal degradation of these nanocomposites have been studied by melt flow index and thermogravimetric analysis. The results show that the addition of carbon nanotubes up to 2wt% increases the viscosity but does not modify significantly the spinnability of the compounds. Moreover, incorporation of these nanofillers allows an improvement of the thermal decomposition. In a second step, these nanocomposites have been processed by melt spinning to produce multifilament yarn. Transmission electron microscopy observations have been done to study carbon nanotubes dispersion and orientation. Nanocomposite morphology correlated with electrical measurements reveal an electrical percolation around 1.5 wt.% without decreasing significantly mechanical properties.

scholarly journals PREPARATON OF MASTERBATCH CONTAINING ANTI-OXIDATION ADDITIVE: EFFECT OF CARRIER RESIN RATIO AND ADDITIVES CONTENT

2018 ◽  
Vol 56 (2A) ◽  
pp. 56-62
Author(s):  
Nguyen Van Khoi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Sem Images ◽  
Elongation At Break ◽  
Limit Value ◽  
Upper Limit ◽  
Anti Oxidant

In this article, we investigated effect of carrier resin ratio and anti-oxidation additives content on properties of anti-oxidant additives Masterbatchs (MBs). The characteristics were measured by: melt flow index (MFI), morphology (SEM), tensile strength and elongation at break. The results indicated that: increasing LLDPE content in carrier resin led to decreasing mechanical properties, MFI weren’t uniform in MBs. With 80/20 of LDPE/LLDPE ratio, the tensile strength and elongation at break values were highest (21.0 MPa, 680.5 %). In addition, when increased anti-oxidant additives content, mechanical properties increased to upper limit value, then decreased. With 25 wt.% of anti-oxidant additives, the tensile strength and elongation at break values were highest (21.0 MPa, 654.7 %), MFI were uniform in MBs (12 g/10 m). SEM images were evidence of greatly distribution in sample containing 25 wt.% additives. Consequently, the 90/10 of LDPE/LLDPE ratio, 25 wt.% anti-oxidant additives were selected to prepare MBs. 

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