scholarly journals Effect of Selected Injection Conditions on the Mechanical Properties and Structure of HDPE

2018 ◽  
Vol 26 (5(131)) ◽  
pp. 93-98
Author(s):  
Katarzyna Mordal ◽  
Karol Dobrakowski ◽  
Dariusz Kwiatkowski
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Polymeric Materials ◽  
Injection Velocity ◽  
Scanning Calorimetry ◽  
Melt Flow Rate ◽  
Variable Parameters ◽  
Injection Process ◽  
Hardness Tests ◽  
Research Plan

This paper is devoted to research of high-density polyethylene (HDPE), which belongs to one of three main biomaterial groups, i.e. polymeric materials. Hence, due to its unique properties, it still plays an important role in biomedical applications – especially in the production of medical equipment, implants and parts of prostheses. This publication deals with the effect of selected conditions of processing which involved injection moulding on the mechanical properties and structure of HDPE mouldings. Samples for tests were produced on a Krauss  Maffei injection moulder on the basis of a research plan prepared using the STATISTICA program. According to this schedule, the following variable parameters of the injection process were selected: injection temperature Tw [C], mould temperature Tf [C] and injection velocity vw [mm/s]. In addition, a part of the moldings was subjected to a few processings. Then the samples obtained were subjected to different tests: tensile, impact and hardness tests, Differential Scanning Calorimetry (DSC) and the melt flow rate (MFR) test in order to determine the influence of selected injection conditions and the multiplicity of processing on the mechanical, rheological and structural properties of HDPE.

scholarly journals Synthesis and Thermo-Mechanical Study of Epoxy Resin-Based Composites with Waste Fibers of Hemp as an Eco-Friendly Filler

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 503
Author(s):  
Mateusz Gargol ◽  
Tomasz Klepka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Polymeric Materials ◽  
Attenuated Total Reflection ◽  
Epoxide Ring ◽  
Infrared Analysis ◽  
Scanning Calorimetry ◽  
Transition Range ◽  
Hardness Tests ◽  
Mechanical Study

The synthesis, thermal, and mechanical properties of epoxy resin composites incorporating waste fibers of hemp were studied. Five different systems with increasing quantity of the eco-filler were obtained. For the synthesis of polymeric materials, the commercial epoxy resins Epidian® 5 and triethylenetetramine (TETA) were applied as crosslinking agents. The composites were obtained based on the polyaddition reaction of an amine group with an epoxide ring. ATR/FT-IR (Attenuated Total Reflection-Fourier Transform Infrared) analysis was used to confirm the chemical structure of the composites and the course of curing processes. Moreover, the influence of the eco-friendly components on the mechanical properties was determined, while thermal properties of the materials were investigated by thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). Dynamic mechanical studies (DMA) and Shore hardness tests of the obtained polymers were also carried out. The DSC curves and DMA analysis revealed that all materials were characterized by a similar glass transition range. Furthermore, the DMA and hardness measurements of the composites demonstrated an increasing elasticity with the increase in the amount of eco-filler present in the compositions.

scholarly journals Modulation of Crystallinity through Radiofrequency Electromagnetic Fields in PLLA/Magnetic Nanoparticles Composites: A Proof of Concept

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4300
Author(s):  
Marta Multigner ◽  
Irene Morales ◽  
Marta Muñoz ◽  
Victoria Bonache ◽  
Fernando Giacomone ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Nanoparticles ◽  
Electromagnetic Fields ◽  
Biomedical Applications ◽  
Infrared Camera ◽  
Proof Of Concept ◽  
Scanning Calorimetry ◽  
Radiofrequency Electromagnetic Fields ◽  
Degradation Properties ◽  
Heat Released

To modulate the properties of degradable implants from outside of the human body represents a major challenge in the field of biomaterials. Polylactic acid is one of the most used polymers in biomedical applications, but it tends to lose its mechanical properties too quickly during degradation. In the present study, a way to reinforce poly-L lactic acid (PLLA) with magnetic nanoparticles (MNPs) that have the capacity to heat under radiofrequency electromagnetic fields (EMF) is proposed. As mechanical and degradation properties are related to the crystallinity of PLLA, the aim of the work was to explore the possibility of modifying the structure of the polymer through the heating of the reinforcing MNPs by EMF within the biological limit range f·H < 5·× 109 Am−1·s−1. Composites were prepared by dispersing MNPs under sonication in a solution of PLLA. The heat released by the MNPs was monitored by an infrared camera and changes in the polymer were analyzed with differential scanning calorimetry and nanoindentation techniques. The crystallinity, hardness, and elastic modulus of nanocomposites increase with EMF treatment.

scholarly journals Morphology and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends

2009 ◽  
Vol 11 (3) ◽  
pp. 27-34 ◽  
Author(s):  
Aleksandra Ratajska ◽  
Wojciech Kulak ◽  
Artur Poeppel ◽  
Andreas Seyler ◽  
Zbigniew Roslaniec
Keyword(s):  
Mechanical Properties ◽  
Vinylidene Fluoride ◽  
Polymeric Materials ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Polyamide 12 ◽  
Poly Vinylidene Fluoride ◽  
Static Tensile ◽  
Internal Mixer ◽  
Morphology And Mechanical Properties

Morphology and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends The morphology, thermal and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends were investigated. These polymers are engineering, semi-crystalline polymers which are reciprocally immiscible. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM) were used to characterize the polymeric materials. Mechanical properties were examined by static tensile test. The investigations demonstrate that blends with higher amount of PVDF, with the morphology of two co-continuous semicristalline phases, exhibit better mechanical properties. The blends with small content of PVDF and prepared by extrusion show the morphology of small separated domains of PVDF and full continuous PA phase. The morphology of these blends is different than the blends prepared by internal mixer and have better mechanical properties too. Thus they can be used in particular applications without a compatibilizing agent.

scholarly journals Graphene-based polymeric nano-composites: an introspection into functionalization, processing techniques and biomedical applications

2019 ◽  
Vol 9 (3) ◽  
pp. 3926-3933 ◽  
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Scientific Community ◽  
Polymeric Materials ◽  
Biomedical Domain ◽  
Polymeric Nanocomposites ◽  
Polymeric Matrices ◽  
Functional Capabilities ◽  
Superior Mechanical Properties ◽  
Processing Techniques

Although, there have been numerous efforts in synthesis of polymers, their mechanical properties have limited their applications. Graphene has been investigated for excellent properties such as superior mechanical properties, high thermal conductivity that has attracted the attention of scientific community to employ graphene as a filler material in polymeric matrices to form composites with multi-functional capabilities. The excellent properties possessed by Graphene has motivated users to fabricate flexible nanocomposites that can be used for applications requiring superior mechanical, chemical and thermal performances. Characteristics of both the components if explored synergistically through proper structural and interfacial organization. The investigation in this direction has resulted into combination of graphene with variety of polymeric materials and hence the development of different graphene-based nanocomposites. The present work reviews the application of graphene-based nanocomposites in the biomedical domain. With this objective, the polymeric matrices suitable for biomedical applications as well as the techniques of producing graphene polymeric nanocomposites have been discussed. Finally the application particularly in biosensing, wound healing and drug delivery system has been discussed.

scholarly journals The research of the thermal and mechanical properties of materials produced by 3D printing method

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1211-1216
Author(s):  
Adam Gnatowski ◽  
Agnieszka Kijo-Kleczkowska ◽  
Henryk Otwinowski ◽  
Piotr Sikora
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
3D Printing ◽  
Thermoplastic Polyurethane ◽  
Polymeric Materials ◽  
Poly Lactic Acid ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Properties Of Materials ◽  
Butadiene Styrene

A comparative analysis of thermal properties of semi-crystalline and amorphous polymeric materials was carried out. Samples were produced using 3D printing technology on the SIGNAL-ATMAT printer. The following polymeric materials were used to make the samples: thermoplastic polyurethane elastomer, acryloni-trile-butadiene-styrene copolymer, Laywood, ethylene terephthalate, poly (lactic acid). The materials were tested for their thermal and mechanical properties. The research included the analysis of thermal properties by differential scanning calorimetry of manufactured materials. The tensile strength also was determined.

scholarly journals Sulfur/Organic Copolymers as Curing Agents for Rubber

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 870 ◽  
Author(s):  
Jakub Wręczycki ◽  
Dariusz Bieliński ◽  
Rafał Anyszka
Keyword(s):  
Mechanical Properties ◽  
Crosslink Density ◽  
Elemental Sulfur ◽  
Freezing Point ◽  
Petroleum Industry ◽  
Polymeric Materials ◽  
Mechanical Analysis ◽  
Radical Copolymerization ◽  
Scanning Calorimetry ◽  
Free Radical Copolymerization

It is widely acknowledged that waste sulfur generated from the petroleum industry creates huge storage and ecological problems. Therefore, the various methods of utilization are becoming increasingly attractive research topics worldwide. The thermal ability of elemental sulfur to homolytic cleavage of S8 rings enables its free radical copolymerization with unsaturated organic species and the obtaining of chemically stable polymeric materials. Here we report a novel possibility to use sulfur/organic copolymers obtained via “inverse vulcanization” as curatives for rubber. For this purpose, several various sulfur/organic copolymers were synthesized and analyzed from the point of view of their performance as rubber crosslinking agents. Solvent extraction was used to purify sulfur/organic copolymers from unreacted (elemental) sulfur. Thermal properties of the prepared copolymers were characterized by thermogravimetric analysis and differential scanning calorimetry (TGA–DSC). Crosslink density and structure of cured elastomers was studied by equilibrium swelling, thiol-amine analysis and freezing point depression. Mechanical properties of the vulcanizates were determined under static and dynamic conditions (DMA—dynamic mechanical analysis). It is proved that the utilization of sulfur/organic copolymers as curatives enables an effective crosslinking process of rubbers. Taking into account the results of a crosslink density analysis and mechanical properties of the vulcanizates cured with purified copolymers, it is evident that relatively long copolymer macromolecules are also involved in the formation of chemical bonds between unsaturated rubber macromolecules.

Silicone/Carbon Nanotube Sheet Biofidelic Piezoresistive Sandwich Composites

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Nengda Jiang ◽  
Sirish Namilae ◽  
Vinu Unnikrishnan
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Polymeric Materials ◽  
Analytical Models ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Human Brain Tissue ◽  
Electrically Conductive ◽  
The Core ◽  
Electromechanical Performance

Abstract Silicone-based biofidelic surrogates are used in many biomedical applications. Apart from mimicking the mechanical behavior of bodily tissues, there is an increasing requirement for these materials to be electrically conductive and piezoresistive to facilitate direct instrumentation. Carbon nanotubes (CNTs) have been extensively investigated as fillers to impart electrical conductivity and piezoresistivity to polymeric materials including silicone. In this paper, we fabricate, test, and characterize a two-part silicone/CNT sheet sandwich composites that exhibit conductivity, piezoresistivity, and biofidelic with mechanical properties corresponding to that of the white matter of human brain tissue. The electromechanical performance of the sandwich composite improves in subsequent loading after the core fracture during initial loading. Analytical models developed for discontinuous core sandwich structures are used to analyze and explain the experimental results. The results indicate the potential for using this discontinuous core biofidelic-piezoresistive sandwich nanocomposite for biomedical applications without deploying external deformation sensors.

scholarly journals The Effect of Halloysite Addition on the Material Properties of Chitosan–Halloysite Hydrogel Composites

Gels ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 40 ◽  
Author(s):  
Luo ◽  
Mills
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Biomedical Applications ◽  
Polymeric Materials ◽  
Halloysite Nanotubes ◽  
Sustained Drug Release ◽  
Nanocomposite Hydrogels ◽  
Naturally Occurring ◽  
Hydrogel Composites ◽  
Chitosan Hydrogels

Chitosan-based hydrogels are being widely used in biomedical applications due to their eco-friendly, biodegradable, and biocompatible properties, and their ability to mimic the extracellular matrix of many tissues. However, the application of chitosan hydrogels has been limited due to their inherent mechanical weakness. Halloysite nanotubes (HNTs) are naturally occurring aluminosilicate clay minerals and are widely used as a bulk filler to improve the performance characteristics of many polymeric materials. HNTs have also been shown to be a viable nanocontainer able to provide the sustained release of antibiotics, chemicals, and growth factors. This study’s objective was to develop a stable drug delivery chitosan/HNT nanocomposite hydrogel that is biocompatible, biodegradable, and provides sustained drug release. In this study, chitosan/HNTs hydrogels containing undoped or gentamicin-doped HNTs were combined in different wt./wt. ratios and cross-linked with tripolyphosphate. The effects of chitosan and HNTs concentration and combination ratios on the hydrogel surface morphology, degradability, and mechanical properties, as well as its drug release capability, were analyzed. The results clearly showed that the addition of HNTs improved chitosan mechanical properties, but only within a narrow range. The nanocomposite hydrogels provided a sustained pattern of drug release and inhibited bacterial growth, and the live/dead assay showed excellent cytocompatibility.

scholarly journals Influence of mechanical properties of polypropylene/low-density polyethylene nanocomposites

2017 ◽  
Vol 7 ◽  
pp. 184798041771592 ◽  
Author(s):  
Bei Su ◽  
Ying-Guo Zhou ◽  
Hai-Hong Wu
Keyword(s):  
Mechanical Properties ◽  
Polymeric Materials ◽  
Underlying Mechanism ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Scanning Calorimetry ◽  
Simple Method ◽  
Polyethylene Composite ◽  
Close Relationship ◽  
Two Phases

The mechanical blending of polypropylene and low-density polyethylene is an economical and simple method for producing new polymeric materials for specific applications. However, the reduction in mechanical properties of the blend is one of its main shortcomings. In this study, a filler masterbatch including nano-silicon dioxide, compatibilizer, lubricant agent, and antioxidant agent was prepared, and polypropylene–low-density polyethylene composite parts with different content of filler masterbatch were fabricated and tested for mechanical properties at two tensile test speeds. Also, to investigate the underlying mechanism of the mechanical properties improvement, the tested samples were carefully analyzed and compared and further characterized by scanning electron microscopy and differential scanning calorimetry. The results indicate that the mechanical properties, including tensile strength, moduli, and elongation, can be all drastically improved simultaneously with the addition of the filler masterbatch. The results also suggest that the compatibility of the two phases increases with the increase in the filler masterbatch, and the crystal size decreases and distribution uniforms owing to the addition of the filler masterbatch. Furthermore, it was also found that there is a close relationship between the mechanical properties and morphological structures, which are improved by the existence of the filler masterbatch.

Ti-Mo-Zr-Ta Alloy for Biomedical Applications: Microstructures and Mechanical Properties

2017 ◽  
Vol 750 ◽  
pp. 184-188 ◽  
Author(s):  
Mădălina Simona Bălţatu ◽  
Petrică Vizureanu ◽  
Marcelin Benchea ◽  
Mirabela Georgiana Minciună ◽  
Dragoş Cristian Achiţei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Toxic Elements ◽  
Medical Application ◽  
Point Of View ◽  
Hardness Tests ◽  
Indentation And Hardness ◽  
Low Modulus ◽  
Microstructures And Mechanical Properties ◽  
Micro Indentation

Titanium alloys are widely used as biomaterials for their excellent properties. In the last years, low modulus β-type Ti-based alloys are being developed. The aim of this paper is developing of an original Ti-based alloy improved with non-toxic elements, characterized from point of view of microstructures and mechanical properties: micro-indentation and hardness tests. Results shown that TiMoZrTa have a small elastic modulus closer to the bone with possible medical application.

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