scholarly journals PP/EPDM Polymeric Compounds Dynamically Cured Compatibilized and Reinforced with Nanoclay

2018 ◽  
Vol 55 (3) ◽  
pp. 335-339
Author(s):  
Mihaela (Vilsan) Nituica ◽  
Aurelia Meghea ◽  
Dana Gurau ◽  
Maria Daniela Stelescu
Keyword(s):  
Polymer Nanocomposites ◽  
Melt Flow Index ◽  
Flow Index ◽  
Chemically Modified ◽  
Polymeric Compounds ◽  
Ft Ir ◽  
Nanometric Particles ◽  
Layered Clay ◽  
Two Stages ◽  
Ethylene Propylene Diene Terpolymer

This paper presents the development of dynamically cured polymer composites and nanocomposites based on plastomer - PP (polypropylene) and EPDM elastomer (ethylene-propylene-diene-terpolymer) compatibilized and reinforced with nanometric particles-MMT (montmorillonite, chemically modified layered clay) in two stages, by extrusion-granulation and mixing. Nanoparticles increase the thermal resistance of dynamically cured polymer nanocomposites. By means of compatibilization and dynamic curing, elastomer particles - EPDM are more easily dispersed in the mixture. The materials obtained were tested physicomechanically (Melt Flow Index) and morpho-structurally (FT-IR and DSC).

scholarly journals Characterization of Polypropylene post-consume / Banana Fiber Composites

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Ariadne Gonçalves De Leão ◽  
Patricia Soares da Costa Pereira ◽  
Daniele Cruz Bastos
Keyword(s):  
Melt Flow Index ◽  
Fiber Composites ◽  
Flow Index ◽  
Slight Reduction ◽  
Banana Fiber ◽  
Chemically Modified ◽  
The Matrix ◽  
Banana Fibre ◽  
Thermal Stability Of

In this study, banana fibre surfaces were chemically modified and composites using polypropylene as a matrix were prepared. The FTIR analysis confirmed that the esterification increased the crystallinity and thermal stability of the acetylated fibres. Composites showed a decrease in the melt flow index and a slight reduction in density and hardness in relation to the matrix. Good matrix/fibre adhesion was observed by SEM micrographs.

scholarly journals OLEOGELS OF OLIVE OIL AND SOYBEAN OIL FOR TOPICAL DRUG DELIVERY: A COMPARATIVE ANALYSIS

2019 ◽  
pp. 4-10
Author(s):  
DIPANJANA ASH ◽  
SUTAPA BISWAS MAJEE ◽  
GOPA ROY BISWAS
Keyword(s):  
Drug Release ◽  
Soybean Oil ◽  
Olive Oil ◽  
Tween 80 ◽  
Melt Flow Index ◽  
Release Profile ◽  
Flow Index ◽  
Drug Release Profile ◽  
Organoleptic Evaluation ◽  
Ft Ir

Objective: The objective of the present investigation was to develop olive and soybean oil-based oleogels with Span 40 and/or Tween 80 (as gelator and/or surfactant) and determine the critical gelator concentration (CGC), characterise and compare the rheological, thermal properties and drug release profile of the gels formed for topical delivery. Methods: Olive and soybean oil-based Span 40 and Span 40/Tween 80 oleogel formulations were prepared by solid fiber mechanism and subjected to organoleptic evaluation, FT-IR spectroscopy, thermal analysis, rheological study, kinetic modeling of gelation and drug release. Results: The critical gelator (Span 40) concentration was found to be lower for olive oil (12% w/v) and depend on the type of oil. Tween 80 reduced CGC of soybean oleogels only. Soybean oil-based oleogel containing 18% w/v Span 40 was found to form more flexible, less viscous and thermally less stable formulation with better release of paracetamol as evident from lower melt flow index, Tg value, lower β and higher α value compared to olive oil-based oleogel with 12% w/v Span 40 (CGC). Surfactant addition can be assumed to modify the microarchitecture of the oleogels to a great extent to produce more flexible and thermally stable gels with even better drug release profile. Span-Tween based soybean oleogel formed a gel-matrix whereas matrix in olive oil-based oleogels containing Span only became slightly flexible to release the drug in zero-order fashion on the addition of surfactant cogelator. Conclusion: Nature of oil exerts profound influence on the rheological, thermal and release profile of oleogels containing Span 40 as gelator and/or Tween 80 as surfactant cogelator.

scholarly journals Designing and obtaining wood waste and chloroprene rubber-based composites

2020 ◽  
Author(s):  
Mihai Georgescu ◽  
Maria Sonmez ◽  
Laurentia Alexandrescu ◽  
Mihaela Nituica ◽  
Maria Daniela Stelescu ◽  
...  
Keyword(s):  
Melt Flow Index ◽  
Wood Waste ◽  
Flow Index ◽  
Filling Material ◽  
Potassium Oleate ◽  
Wood Particles ◽  
Ft Ir ◽  
Chloroprene Rubber ◽  
Reinforcing Material ◽  
Elastomer Composites

The aim of this paper is to obtain and study the properties of wood waste reinforced elastomer composites with various fibre contents (10-50 wt%). The composite is based on chloroprene rubber, and added post-consumer recycled wood particles, with dimensions of 500 nm eco-reinforcing material, and active fillers, plasticizers, vulcanizing agents, antioxidants. In order to enhance the compatibility and their level of interaction, the wood waste was finely ground (cryogenic mill) and functionalized with potassium oleate. Wood waste acts as a filling material which leads to the biodegradability of the composite and the decrease in density. Tensile, tear strength, elasticity, hardness, abrasion resistance, melt flow index and morphological study (FT-IR) of those composites were examined in order to determine the viability in various applications domains.

scholarly journals Reactive Extrusion of Polyethylene Terephthalate Waste and Investigation of Its Thermal and Mechanical Properties after Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mahmoud A. Mohsin ◽  
Tahir Abdulrehman ◽  
Yousef Haik
Keyword(s):  
Polyethylene Terephthalate ◽  
Mechanical Characteristics ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Flow Index ◽  
Carbonyl Groups ◽  
Melt Flow ◽  
Pet Waste ◽  
Ft Ir ◽  
Ir Analysis

This study investigates treating polyethylene terephthalate (PET) waste water bottles with different mass of ethylene glycol (EG) using reactive extrusion technique at a temperature of 260°C. The study puts emphases on evaluating the thermal, mechanical, and chemical characteristics of the treated polyethylene terephthalate. The properties of the treated PET from the extruder were analyzed using FT-IR, TGA, DSC, and nanoindentation. The melt flow indexes (MFI) of both treated and untreated PET were also measured and compared. Thermal properties such as melting temperature (Tm) for treating PET showed an inversely proportional behavior with the EG concentrations. The FT-IR analysis was used to investigate the formation of new linkages like hydrogen bonds between PET and EG due to the hydroxyl and carbonyl groups. Nanoindentation results revealed that both the mechanical characteristics, elastic modulus and hardness, decrease with increasing EG concentration. On the other hand, the melt flow index of treated PET exhibited an increase with increasing EG concentration in the PET matrix.

scholarly journals РОЗРОБКА АНТИСТАТИЧНИХ І НАПІВПРОВІДНИКОВИХ КОМПОЗИЦІЙ ПОЛІЕТИЛЕН/ПОЛІАНІЛІН ТА ПОЛІВІНІЛХЛОРИД/ПОЛІАНІЛІН

2020 ◽  
Vol 138 (5) ◽  
pp. 71-78
Author(s):  
Д. С. Новак ◽  
В. П. Плаван ◽  
Ю. В. Гуленок ◽  
В. О. Стіхіляс
Keyword(s):  
Tensile Strength ◽  
Electrical Resistance ◽  
Specific Volume ◽  
Volume Concentration ◽  
Relative Elongation ◽  
Composite Films ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Two Stages

The effect of the polyaniline content on the mechanical, rheological and electrical properties of polyethylene and polyvinylchloride compositions for the production of antistatic and semiconductive materials was established. Samples of polymer composites were obtained in two stages: 1) mixing of components in a mixer type "disk in disk"; 2) pressing into films by the method of "hot pressing." Tensile strength, relative elongation, melt flow index and specific volume electrical resistance of the compositions were investigated by standard methods. It was found that an increase in the volume content of polyaniline in the polyethylene and polyvinylchloride matrix leads to a monotonic decrease in the melt flow index, as well as tensile strength and relative elongation. At the same time, there is a significant decrease in the specific volume electrical resistance in polyethylene and polyvinylchloride composite films, which contain up to 30% vol. of polyaniline. The reduction of the tensile strength and the relative elongation of films from compositions containing up to 30% vol. of polyaniline. This is due to the decrease in the viscosity of the melt-filled compositions, as evidenced by the decrease in the flow index of the melt polyethylene compositions from 3 to 2 g / 10 min, and polyvinylchloride – from 13 to 3 g / 10 min. Specific volume electrical resistance naturally decreases with increasing volume concentration of the filler in ranges from 1014 to 102 Ohm ∙ m for polyethylene compositions and from 1010 to 101 Ohm ∙ m for polyvinylchloride compositions. The developed polyethylene and polyvinylchloride compositions filled with polyaniline can be used for the production of polymer products with antistatic and semiconductive properties.

Synthesis of Zirconium Tungstate by Hydrothermal Method

2011 ◽  
Vol 322 ◽  
pp. 201-204
Author(s):  
Li Yun Zheng ◽  
Zhi Wei Yang
Keyword(s):  
Hydrothermal Method ◽  
Negative Thermal Expansion ◽  
Dehydration Reaction ◽  
Large Size ◽  
Thermal Analyzer ◽  
Specific Direction ◽  
Endothermic Process ◽  
Ft Ir ◽  
Hcl Concentration ◽  
Two Stages

Negative thermal expansion material ZrW2O8 was synthesized by hydrothermal method. The prepared ZrW2O8 and the precursor were characterized by x-ray diffractometer, thermo-gravimetric/differential thermal analyzer, FT-IR spectrometer and scanning electron microscope. The results show that a single-phase ZrW2O8 can be synthesized when HCl concentration is as low as 4mol/L. ZrW2O8 was obtained through the precursor dehydration and debonding O-H bond. The dehydration reaction includes two stages. There is a sharp endothermic peak in the first stage of the dehydration reaction and the second stage is a slow endothermic process. A new phase appeared when the sintering temperature is above 600 °C. ZrW2O8 and the precursor have the same rod-like shape and grow up along a specific direction. The synthesized ZrW2O8 particles obtained from 4mol/L HCl appeared large size. It became much finer and the rod with multiple crystal face was easy to form when the concentration of HCl increased to 6~8 mol/L.

scholarly journals Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 390
Author(s):  
Fernando Luiz Lavoie ◽  
Marcelo Kobelnik ◽  
Clever Aparecido Valentin ◽  
Érica Fernanda da Silva Tirelli ◽  
Maria de Lurdes Lopes ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Morphological Changes ◽  
Field Performance ◽  
Melt Flow Index ◽  
Flow Index ◽  
Test Results ◽  
Upward Trend ◽  
Scanning Calorimetry ◽  
Ultraviolet Exposure ◽  
Brittle Behavior

High-density polyethylene (HDPE) geomembranes are polymeric geosynthetic materials usually applied as a liner in environmental facilities due to their good mechanical properties, good welding conditions, and excellent chemical resistance. A geomembrane’s field performance is affected by different conditions and exposures, including ultraviolet radiation, thermal and oxidative exposure, and chemical contact. This article presents an experimental study with a 1.0 mm-thick HDPE virgin geomembrane exposed by the Xenon arc weatherometer for 2160 h and the ultraviolet fluorescent weatherometer for 8760 h to understand the geomembrane’s behavior under ultraviolet exposure. The evaluation was performed using the melt flow index (MFI) test, oxidative-induction time (OIT) tests, tensile test, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. The sample exposed in the Xenon arc equipment showed a tendency to increase the MFI values during the exposure time. This upward trend may indicate morphological changes in the polymer. The tensile behavior analysis showed a tendency of the sample to lose ductility, without showing brittle behavior. The samples’ OIT test results under both device exposures showed faster antioxidant depletion for the standard OIT test than the high-pressure OIT test. The DSC and FTIR analyses did not demonstrate the polymer’s changes.

scholarly journals Enhancement of mechanical, thermal and water uptake performance of TPU/jute fiber green composites via chemical treatments on fiber surface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Tuffaha Fathe Salem ◽  
Seha Tirkes ◽  
Alinda Oyku Akar ◽  
Umit Tayfun
Keyword(s):  
Water Absorption ◽  
Water Uptake ◽  
Mechanical Test ◽  
Fiber Surface ◽  
Melt Flow Index ◽  
Jute Fiber ◽  
Morphological Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Treatment Type

AbstractChopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (Tg) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.

scholarly journals Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments

2021 ◽  
Vol 22 (14) ◽  
pp. 7438
Author(s):  
Paulina Kasprzyk ◽  
Ewa Głowińska ◽  
Paulina Parcheta-Szwindowska ◽  
Kamila Rohde ◽  
Janusz Datta
Keyword(s):  
Chemical Structure ◽  
Melt Flow Index ◽  
Molar Ratio ◽  
Flow Index ◽  
Step Method ◽  
Elongation At Break ◽  
Molecular Weights ◽  
Trimethylene Glycol ◽  
Hard Segments ◽  
A Chain

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

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.

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