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 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.

Thermomechanical investigations of PEKK-HAp-CS composites

2019 ◽  
Vol 233 (11) ◽  
pp. 1196-1203
Author(s):  
Rupinder Singh ◽  
Gurchetan Singh ◽  
Jaskaran Singh ◽  
Ranvijay Kumar ◽  
Md Mustafizur Rahman ◽  
...  
Keyword(s):  
Melt Flow Index ◽  
Extrusion Process ◽  
Flow Index ◽  
Fused Deposition Modelling ◽  
Index Test ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Ether Ketone ◽  
Input Variables

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.

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.

Investigation the mechanical, rheological, and morphological properties of acrylonitrile butadiene styrene blends with different recycling number content

2017 ◽  
Vol 232 (4) ◽  
pp. 449-458 ◽  
Author(s):  
Ibrahim Hamarat ◽  
Emel Kuram ◽  
Babur Ozcelik
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Acrylonitrile Butadiene Styrene ◽  
Melt Flow Index ◽  
Morphological Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Recycled Polymer ◽  
Recycled Material ◽  
Butadiene Styrene

In this study, acrylonitrile butadiene styrene polymer was exposed to 12 injection cycles to investigate the influence of recycling number on the mechanical, rheological, and morphological properties. Also, binary and ternary blends including different weight percentages and recycling number of virgin–recycled polymers were prepared. A slight decrement was found in the tensile strength values with recycling number. All blends including recycled polymer (binary or ternary) gave lower tensile strength values with respect to 100% virgin polymer. Strain at break value was decreased after twelve times recycling; however, no clear tendency was observed with the presence of different ratios of virgin polymer to recycled polymer. Impact strength of the polymer decreased with recycling number. There was relatively large drop in the third recycling, from 72 kJ/m2 to 38.5 kJ/m2; however, further recycling induced in a slower drop in the impact strength to 32.5 kJ/m2. All blends including recycled material gave lower impact strength values as compared to 100% virgin polymer. It was observed that the melt flow index values increased with the recycling number, a total of 26.53% after twelve times recycling. All blends containing recycled material showed higher melt flow index values as compared to 100% virgin polymer.

scholarly journals Bio-Copolyesters of Poly(butylene succinate)(PBS) Containing Long Chain Bio-Based Glycol

2019 ◽  
Author(s):  
Karolina Stępień ◽  
Cathrine Miles ◽  
Andrew McClain ◽  
Ewa Wiśniewska ◽  
Peter Sobolewski ◽  
...  
Keyword(s):  
Linear Trend ◽  
Melt Flow Index ◽  
Pilot Scale ◽  
Elastic Behavior ◽  
Flow Index ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Weight Density ◽  
Long Chain

<p>Poly(butylene succinate) (PBS) is a thermoplastic and biodegradable polyester characterized by high rigidity due to its high crystallinity. However, the use of long chain biobased monomers to produce segmented copolymers is an effective strategy to tailor the properties of PBS, such as greater flexibility. In this paper, a series of aliphatic bio-copolyesters of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) were successfully synthesized <i>via </i>a direct two-step polycondensation method using a semi-pilot scale reactor for melt polymerization and titanium dioxide/silicon dioxide coprecipitate catalyst (C-94). In this study, the thermal and mechanical properties were investigated and compared, focusing on the effect of varying the amount of biobased dilinoleic diol in the structure. With increasing amount of long chain diol, a decrease in molecular weight, density, and melt flow index was observed. The semicrystalline nature of the copolymers was confirmed using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) methods. These copolymers exhibit two main transition temperatures and vary in softness and processing flexibility. Furthermore, in the DSC data a linear trend was observed with increasing wt.% of hard PBS segments, which can be described by the Gordon-Taylor equation. Increasing the soft DLS segment content in the copolymer series resulted in an increase in the elastic behavior of the polymers. The broad range of crystallization temperatures and melt flow index values indicates that a polyester library with customizable properties that spans PBS applications has been successfully obtained.</p>

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.

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 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).

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