scholarly journals Effect of thermal degradation on rheological properties of polymeric materials

2019 ◽  
Vol 299 ◽  
pp. 06001
Author(s):  
Jozef Dobránsky ◽  
Zigmund Doboš
Keyword(s):  
Shear Rate ◽  
Thermal Degradation ◽  
Rheological Properties ◽  
Flow Rate ◽  
Polymeric Materials ◽  
Volume Index ◽  
Melt Flow ◽  
Molding Machine ◽  
Molding Process ◽  
Melt Flow Rate

The aim of this paper is to monitor the melt volume index of thermoplastic materials and other rheological properties such as shear rate and viscosity. The aim is to compare and assess whether several times ground and subsequently re-melted samples of pure polymer granulate will have the same or similar rheology properties and whether adjustment of the injection molding machine will be required or willneed to reduce or increase production times. Thermo Scientific with HAAKE Meltflow MT software was used to determine the melt flow rate index (MVR) of thermoplastic materials. Based on the melt flow rate (MVR), shear rate and viscosity evaluation, it has been found that, although the selected materials have undergone multiple changes in the rheology of the polymeric materials, there is no problem in the molding process, and MVR does not change significantly. In this case, no changes in the settings of theinjection molding machines and reduction or increase in production times will be necessary. When re-melting the granulate samples, no excess waste was generated, which would then need to be disposed of and the samples could be re-used for further measurement after grinding.

PREDICTING THE FLOW PROPERTIES OF POLYAMIDE NANOCOMPOSITES BY USING VINOGRADOV-MALKIN MODEL

2015 ◽  
Vol 9 (3) ◽  
pp. 2446-2452
Author(s):  
Tomasz Mariusz Majka ◽  
Marcin Majka ◽  
Muhammad Kamrul Hasan
Keyword(s):  
Shear Rate ◽  
Flow Direction ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Polyamide 6 ◽  
Flow Index ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Shear Rates ◽  
Different Temperatures

This article reports the prediction of the theoretical flow curves of polyamide composites by using Vinogradov-Malkin model. Determination of the melt flow index of polymeric materials is the first step to study viscosity-shear rate relationship. The viscosity of the composites at different temperatures were calculated by using the Williams, Landel'a and Ferry (WLF) equation. Other important rheological characteristics were calculated by using appropriate equations. One point method is employed to correlate the changes in viscosity with temperatures. As expected, it is found that incorporation of nanoclay to polyamide 6 (PA6) significantly decreases the Melt Flow Rate of the composites and hence, increases density. Addition of stabilizer further increases density of the PA6/nanoclay composites. The simulations of viscosity curves for PA6 composites were carried out at measurement temperature, 240°C and in the range of 180°C - 350°C with shear rate of 10-1 – 103 1/s. It is found that addition of nanoclay and stabilizer to PA6 decreases viscosity of the composites in the order of PA6/OMMT > PA6 > PA6/I1098 > PA6/OMMT/I1098 > PA6/MMT/I1098 > PA6/MMT. At higher shear rates, viscosity decreases in the same sequence as low shear rates. At further higher shear rates (> 1000 1/s), filler particles are arranged in the flow direction thus exerting no significant effect on viscosity of composites both with and without the stabilizer. During injection moulding in the shear rate ranging from 101 – 104 1/s at 240°C temperature, it is evident that viscosity decreases drastically with increase in shear rate.

Investigation of the Properties of Polyetheretherketone Blends and Carbon-Filled Composites Based on them

2021 ◽  
Vol 899 ◽  
pp. 426-433
Author(s):  
Azamat L. Slonov ◽  
Ismel V. Musov ◽  
Elena V. Rzhevskaya ◽  
Khasan V. Musov ◽  
Aslanbek F. Tlupov ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Rheological Properties ◽  
Flow Rate ◽  
Relative Difference ◽  
Mechanical And Thermal Properties ◽  
Additivity Rule ◽  
Melt Flow ◽  
Melt Flow Rate

The study of the properties of PEEK blends with different melt flow rate (MFR) and carbon-filled composites based on them was carried out. It was found that with an increase in the relative difference in the MFR of the blended PEEKs, there is an increase in the deviation of the experimental MFR values from the additive ones. Up to a relative difference in the MFR of the components equal to 60%, the blends obey the additivity rule. It is shown that the achievement of a certain MFR value by blending polymers with different viscosities leads to the production of materials with similar properties. Carbon-filled composites based on PEEK blends also demonstrate very similar rheological, mechanical and thermal properties, which indicates the effectiveness of the method of blending PEEKs with different viscosities to achieve the required rheological properties.

Study on Rheological Properties of Polylactic Acid Retardant System

2014 ◽  
Vol 488-489 ◽  
pp. 293-296
Author(s):  
Dong Ze Li ◽  
Xiao Chuan Jia ◽  
Xiu Ping Lu ◽  
Sheng Jia Zhai
Keyword(s):  
Flame Retardant ◽  
Rheological Properties ◽  
Polylactic Acid ◽  
Flow Rate ◽  
Flame Retardants ◽  
Complex Viscosity ◽  
Intumescent Flame Retardant ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Scanning Frequency

A series of polylactic acid (PLA)/IFR composites was prepared by melt blending method.Capillary rheometer and rotary rheometer were applied to investigate the effects of and flame retardants on rheological properties. The results of the rheological test show that the melt flow rate increases with the increasing of content of Intumescent flame retardant. Intumescent flame retardant joined making PLA system flow rate is larger than pure PLA, melt flow rate increases, apparent viscosity decreases, relaxation time decreases, and the complex viscosity decreases gradually with the increase of scanning frequency.

Study of Ultrasonic-Assisted High Light Seamless Injection Molding Process and Technology

2010 ◽  
Author(s):  
Jibin Li ◽  
Keke Xu ◽  
Haixiong Wang ◽  
Haijun Liu
Keyword(s):  
Injection Molding ◽  
Flow Rate ◽  
Ultrasonic Field ◽  
High Light ◽  
Injection Molding Process ◽  
Melt Flow ◽  
Molding Process ◽  
Melt Flow Rate ◽  
Ultrasonic Assisted ◽  
Different Temperatures

This paper rebuilt a set of melt flow rate instrument which is loaded a power adjustable ultrasonic device. The melt flow rate (viscosity curve) is studied on three kinds of plastic materials, PC, ABS, and PMMA, at different temperatures. The variation of melt flow rate is analyzed under the ultrasonic field. In addition, the practicability of ultrasonic-assisted high light seamless injection molding process and technology is tested and discussed.

Effect of Compatibilization on the Melt Properties of Mixed Waste Plastics

2019 ◽  
Vol 814 ◽  
pp. 522-526
Author(s):  
Ossi Martikka ◽  
Suman Nepal ◽  
Marko Hyvärinen ◽  
Timo Kärki
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Flow Rate ◽  
Volume Index ◽  
Waste Plastics ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Waste Plastic ◽  
Important Material ◽  
Mixed Waste

The amount of waste produced increases globally, and valuable resources are lost if materials contained in wastes are not recycled. One such important material group is plastics, but it is typically mixed in municipal solid waste. In this paper, the effect of maleic compatibilizer on the melt properties of mixed waste plastic is studied in order to evaluate the effect of compatibilization on the processability of reclaimed plastics. The results indicate, that compatibilization has significant effect on both melt flow rate and melt volume index. Both are decreased notably, suggesting that compatibilization may impair the processability of mixed waste plastic, even though it is expected to improve other properties.

Effect of Powder Properties such as Particle Size, Density and Melt Flow Rate on the Properties of Flame Sprayed PE Coating

2000 ◽  
Author(s):  
E. Rajamäki ◽  
M. Leino ◽  
P. Vuoristo ◽  
P. Järvelä ◽  
T. Mäntylä
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flow Rate ◽  
Heating Temperature ◽  
Steel Substrate ◽  
Great Influence ◽  
Hot Water ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Powder Properties

Abstract Three different types of polyethylene powders were flame sprayed onto pre-heated steel substrate previously coated by electrostatic spray system with a thin epoxy primer layer. Properties of the polyethylene (PE) powders, including powder density, particle size and melt flow rate (MFR) were measured in order to study their influence on the mechanical properties of the coating. The spray experiments started with optimization of spraying parameters. The main variables were pre-heating temperature of the substrate, temperature increase during spraying (influenced by the spraying distance), and thickness of the PE coatings. The laboratory tests performed for the coatings were coating characterization by microscopy and mechanical testing. Porosity and thickness of the coatings were determined by optical and stereo microscopy studies from polished cross-sectional samples. Hardness, impact strength, peel strength, and adhesive strength of the coatings were also investigated. Also some hot water sinking and heat cycling tests were performed. As a result from the present studies it can be concluded that powder properties have great influence on the mechanical properties of the final coating.

Effect of Different Molecular Weight of PEG on the Crystallization Behaviors of Binary Polymer Blends PLA/TPS

2021 ◽  
Vol 1035 ◽  
pp. 918-924
Author(s):  
Teng Zhang ◽  
Su Mei Zheng
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Flow Rate ◽  
Crystallization Rate ◽  
Thermoplastic Starch ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Melt Flow Rate ◽  
Poly Ethylene ◽  
Different Molecular Weight

Serial poly (lactic acid) (PLA) and thermoplastic starch (TPS) blends (with a fixed content of 20 wt.% TPS) were prepared by melt extrusion process. The effect of different molecular weight of PEG on the thermal and rheological properties of PLA/TPS blends was studied by the melt flow rate (MFR) and DSC analysis. The results showed that the molecular weight of PEG influenced the miscibility and crystallization behavior of PLA/TPS blends. Blend added with PEG400 showed a single Tg, and blends with PEG600 provided remarkable improvement of rheological properties with an increase in flow rate to 49.02 g/10 min. 4% content of poly (ethylene glycol) (PEG) can positively contribute to improve crystallization rate of PLA by reducing the melting temperature and cold crystallization temperature.

scholarly journals Polyethylene-Matrix Composites with Halloysite Nanotubes with Enhanced Physical/Thermal Properties

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 787 ◽  
Author(s):  
Janusz W. Sikora ◽  
Ivan Gajdoš ◽  
Andrzej Puszka
Keyword(s):  
Impact Strength ◽  
Flow Rate ◽  
Softening Temperature ◽  
Halloysite Nanotubes ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Flow ◽  
Polyethylene Matrix ◽  
Melt Flow Rate ◽  
Heat Deflection Temperature

The aim of the present work is to investigate the effect of halloysite nanotubes (HNT) on the mechanical properties of low-density polyethylene composites modified by maleic anhydride-grafted PE (PE-graft-MA). Polyethylene nanocomposites were prepared using an injection molding machine, Arburg Allrounder 320 C 500–170; the HNT content was varied at 0 wt %, 2 wt %, 4 wt % and 6 wt %, and the PE-graft-MA content was varied at 5 wt %. The composites were examined for their ultimate tensile stress, strain at ultimate stress, hardness, impact strength, melt flow rate, heat deflection temperature, Vicat softening temperature, crystallinity degree and phase transition temperature. It was found that the addition of halloysite nanotubes to low-density polyethylene (LDPE) led to an increased heat deflection temperature (HDT, up to 47 °C) and ultimate tensile strength (up to 16.00 MPa) while the Vicat softening temperature, strain at ultimate stress, impact strength and hardness of examined specimens slightly decreased. Processing properties of the materials specified by the melt flow rate (MFR) deteriorated almost twice. The results have demonstrated that the nanoparticles can reinforce enhance LDPE at low filler content without any considerable loss of its ductility, but only when halloysite nanotubes are superbly distributed in the polyethylene matrix.

Sign in / Sign up

Export Citation Format

Share Document