scholarly journals Effect of interaction from the reaction of carboxyl/epoxy hyperbranched polyesters on properties of feedstocks for metal injection molding

2021 ◽  
Author(s):  
Guoming Chen ◽  
Haihong Ma ◽  
Zhengfa Zhou ◽  
Fengmei Ren ◽  
Weibing Xu
Keyword(s):  
Flexural Modulus ◽  
Epoxy Group ◽  
Melt Flow Index ◽  
Metal Injection Molding ◽  
Flow Index ◽  
Carboxyl Group ◽  
Hyperbranched Polyester ◽  
Hyperbranched Polyesters ◽  
Solids Loading ◽  
Shape Retention

Abstract The purpose of this study is to improve the properties of the feedstocks and shape retention of debinded parts by the reaction between 17-4PH stainless steel powders. Carboxyl-terminated hyperbranched polyester (CTHP) and epoxy-terminated hyperbranched polyester (ETHP) were used to treat the powders, and termed as CTHP-m and ETHP-m with carboxyl and epoxy group, respectively. Comparing with pristine, CTHP-m and ETHP-m, feedstock prepared from equal amount of CTHP-m and ETHP-m (CTHP-m/ETHP-m) possessed more excellent properties. The experimental results showed that the critical solids loading, flexural modulus, density and melt flow index of CTHP-m/ETHP-m feedstock were 63.8 vol.%, 2800 Mpa, 5.06 g/cm3 and 62 g/10min, respectively, which were obviously higher than that of others. Also, the shape retention of CTHP-m/ETHP-m debinded parts was the best of all the samples. The improved properties of CTHP-m/ETHP-m feedstock were attributed to the powder interaction between CTHP-m and ETHP-m formed by the chemical reaction between epoxy and carboxyl group.

scholarly journals Study on Improving the Processability and Properties of Mixed Polyolefin Post-Consumer Plastics for Piping Applications

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 71
Author(s):  
Emilia Garofalo ◽  
Luciano Di Maio ◽  
Paola Scarfato ◽  
Arianna Pietrosanto ◽  
Antonio Protopapa ◽  
...  
Keyword(s):  
Yield Strength ◽  
Flexural Modulus ◽  
Melt Flow Index ◽  
Pilot Scale ◽  
Flow Index ◽  
Flow Properties ◽  
Mechanical Recycling ◽  
Flexible Packaging ◽  
Upgrading Strategies ◽  
Mechanical Performances

This study focuses on the upgrading strategies to make Fil-s (acronym for film-small), a polyolefin-based material coming from the mechanical recycling of post-consumer flexible packaging, fit for re-use in the piping sector. The effects of washing treatments (at cold and hot conditions) and the addition of an experimental compatibilizer on the chemical-physical properties of Fil-s were first assessed. The measurements of some key properties (density, melt flow index, flexural modulus, yield strength), for both Fil-s as such and the different developed Fil-s based systems, was also conducted in order to evaluate the suitability of this complex and challenging waste stream to replace virgin PE-based pipe and fitting products, in compliance to ASTM D3350 standard. The outcomes of the present work contributed to define a code, for each Fil-s system investigated, useful for identifying the level of their performance in piping applications. All the recyclates were extruded as pipes by using a pilot scale plant, but the process resulted more stable and continuous with the compatibilized Fil-s, as it was deducible from its flow properties. Moreover, the best mechanical performances were exhibited by the hot-washed Fil-s pipes, with an increase in pipe stiffness equal to 65% respect to the unwashed sample.

Binder System for Coarse Powders Processed by Metal Injection Molding (MIM)

2008 ◽  
Vol 591-593 ◽  
pp. 169-173
Author(s):  
A.P.G. Nogueira ◽  
Ricardo Machado ◽  
Paulo A.P. Wendhausen ◽  
Diego Fernando Portaluppi
Keyword(s):  
Particle Size ◽  
Injection Molding ◽  
Dimensional Accuracy ◽  
Melt Flow Index ◽  
Metal Injection Molding ◽  
Flow Index ◽  
Binder System ◽  
Sintered Part ◽  
Dimensional Deviation ◽  
Modified Binder

Research on determined alloys produced by metal injection molding has been done for cost reduction purposes through the use of powders with bigger particle size. However, regarding feedstock homogeneity, certain limitations are presented when coarse particles are used. For instance, homogeneity strongly influences rheological behavior of the feedstock and dimensional control of the sintered part. Therefore, the purpose of this work was to evaluate effectiveness of a modified binder system with the addition of a surfactant polymer which makes the feedstock more homogeneous. This study was carried out on a FeNiP alloy currently processed by MIM, where 50%wt of the iron powder was replaced with course powder having a particle size distribution of D90 less than 47 ,m. Effectiveness of binder systems using a Melt Flow Index (MFI) and the behavior of dimensional accuracy at sintered part were analyzed. Results showed more feedstock homogeneity and less dimensional deviation when a surfactant agent was used.

Influence of MMT as reinforcement on rheological behavior, mechanical and morphological properties of recycled PET/ABS thermoplastic nanocomposites

2012 ◽  
Vol 32 (3) ◽  
Author(s):  
Mohd Zahidfullah Abd Razak ◽  
Agus Arsad ◽  
Abdul Razak Rahmat ◽  
Azman Hassan
Keyword(s):  
Shear Viscosity ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Acrylonitrile Butadiene Styrene ◽  
Melt Flow Index ◽  
Morphological Properties ◽  
Flow Index ◽  
Maximum Point ◽  
Recycled Pet ◽  
Poly Ethylene

Abstract The objective of this research was to investigate the effect of incorporating nanofiller, montmorillonite (MMT) on mechanical, morphological and rheological properties of acrylonitrile-butadiene-styrene (ABS) and recycled poly(ethylene terephthalate) (rPET) nanocomposites. The MMT contents in 70:30 ABS/rPET and 30:70 ABS/rPET ranged from 1 to 5 wt%. The ABS/rPET nanocomposites were extruded and injection-molded into tensile, flexural and impact test samples. Samples underwent rheological testing by using melt flow index (MFI) and capillary rheometer and the morphology of the nanocomposites was investigated by using field emission scanning electron microscopy (FESEM). The maximum tensile strength and flexural strength were at 1 wt.% of MMT for both blends. However, tensile modulus and flexural modulus reached maximum point at 3 wt.% and started to decrease beyond 3 wt.%% of MMT. Impact strength for both blending decreased significantly with the incorporation of MMT. MFI values decreased with the increment of MMT for 30:70 ABS/rPET, but increased for 70:30 ABS/rPET. The incorporation of MMT increased the melt strength of 30:70 ABS/rPET nanocomposites. Shear viscosity showed increment with the increasing MMT concentration for 30:70 ABS/rPET nanocomposites. However, shear viscosity decreased with the increment of MMT for 70:30 ABS/rPET. FESEM micrographs show good distribution and dispersion of MMT in 30:70 ABS/rPET, but poor dispersion and agglomeration of MMT in 70:30 ABS/rPET.

scholarly journals PHYSICOMECHANICAL PROPERTIES OF NANOCOMPOSITES BASED ON COPOLYMERS OF ETHYLENE WITH α-OLEFINS AND CLINOPTILOLITE

2020 ◽  
pp. 22-27
Author(s):  
N.T. Kakhramanov ◽  
◽  
I.V. Bayramova ◽  
V.S. Osipchik ◽  
A.D. Ismayilzade ◽  
...  
Keyword(s):  
Particle Size ◽  
Tensile Stress ◽  
Heat Resistance ◽  
Flexural Modulus ◽  
Melt Flow Index ◽  
Ultimate Tensile Stress ◽  
Physicomechanical Properties ◽  
Flow Index ◽  
Ethylene Copolymers ◽  
Elongation At Break

The results of studying the effect of clinoptilolite concentration on the properties of nanocomposites based on of ethylene with butylene and of ethylene with hexene copolymer are presented. The effect of clinoptilolite particle size on ultimate tensile stress, elongation at break, flexural modulus, heat resistance, and melt flow index of composites was studied. It is shown that nanocomposites based on ethylene copolymers are characterized by higher values of physicomechanical properties. The additional use of ingredients such as alizarin and calcium stearate contributes to a significant improvement in the complex of properties of nanocomposites based on ethylene copolymers and clinoptilolite

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.

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.

Rheological Study on of PBT with High Melt Flow Index

2012 ◽  
Vol 487 ◽  
pp. 644-648
Author(s):  
Yuan Liu ◽  
Lin Wang ◽  
Qing Yan Xu ◽  
Pei Jie Lin ◽  
Zhi Hong Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Flow Activation Energy ◽  
Nonwoven Fabrics ◽  
Flow Activation ◽  
High Flexibility

Melt-blown generated PBT nonwoven fabrics usually have small fibril diameter, high flexibility, well heat and oil resistance. Therefore, they would have promising application such as vehicle filtering media. The rheological behavior of PBT with High Melt Flow Index for Melt-blown is investigated in this paper. It is a direction of the technology design and fabrication parameters .The relation of apparent viscosity and shear rate is analyzed, as well as flow activation energy and Non-Newtonian indexes. The results suggest that PBT with High Melt Flow Index is Non-Newtonian fluid. Apparent viscosity and flow activation energy show gradually decrease with increasing shear rate, exhibiting typical shear-thinning behavior.

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