scholarly journals The viscoelastic properties of a halogen-free polymer composition, for cable products

2021 ◽  
pp. 67-74
Author(s):  
Olena Chulieieva ◽  
Volodymyr Zolotaryov ◽  
Volodymyr Chulieiev ◽  
Tetiana Kuleshova ◽  
Mykola Suslin
Keyword(s):  
Shear Rate ◽  
Polymer Matrix ◽  
Viscoelastic Properties ◽  
Polymer Composition ◽  
Low Density Polyethylene ◽  
Die Swell ◽  
Linear Low Density Polyethylene ◽  
Swell Ratio ◽  
Halogen Free ◽  
Melt Density

The viscoelastic properties of a halogen-free polymer composition for cable products have been investigated. The influence of temperature parameters, shear rate on the die-swell ratio of the polymer composition has been determined; the dependence of the melt density on a temperature was investigated. The polymer matrix is a mixture of polyolefins (linear low density polyethylene; polyolefin elastomer and maleic anhydride modified linear low density polyethylene) as a flame retardant filler for the polymer composition is trihydrate alumina. The content of flame retardant filler in the polymer composition is 60 %. The polymer composition was manufactured on the compounding line of X-Compound, Switzerland. The investigation of both melt density and die-swell ratio of the polymer composition has been conducted with help of capillary viscometer type IIRT-AM. To determine the density of the melt the ratio of capillary length to diameter L/D=8/2 was used. The results of the study of the dependence of the melt density of the polymer matrix from a temperature of 150–190 °C at different loads showed that this parameter decreases from 789 to 744 kg/m3 and for polymer composition from 1309 to 1268 kg/m3. The die-swell ratio in the case of an increase of the shear rate at temperatures of 150–190°C for the polymer matrix increases from 1,102 to 1,520, and for the polymer composition decreases from 1,056 to 1,018. The investigation results of the dependence of both die-swell ratio of the polymer matrix and the polymer composition on the ratio of the length of the forming tool to the diameter indicates that the die-swell ratio for the polymer matrix was reduced from 1,296 to 1,152, and for the polymer composition from 1,045 to 1,01. It was established that the viscoelastic properties of the halogen-free polymer composition are significantly influenced by: processing temperature, shear rate, melt density, the ratio of the length of the forming tool to the diameter. The research results give a possibility for a reasonable approach for the determination of technological parameters of an insulation, sheathing of power cables and optical cables of microtube construction. It will also allow to quickly adjust the geometrical parameters of the forming tool of cable heads.

RHEOLOGICAL CHARACTERISTICS OF NANOCOMPOSITES BASED ON CLINOPTILOLITE AND LINEAR POLYETHYLENE OF LOW DENSITY

2018 ◽  
Vol 61 (7) ◽  
pp. 106
Author(s):  
Najaf T. Kakhramanov ◽  
Neli S. Koseva ◽  
Rena V. Kurbanova ◽  
Ilaha V. Bayramova ◽  
Nushaba B. Arzumanova ◽  
...  
Keyword(s):  
Shear Rate ◽  
Polymer Matrix ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Rheological Characteristics ◽  
Linear Low Density Polyethylene ◽  
Flow Curves ◽  
Linear Polyethylene ◽  
Natural Minerals ◽  
First Time

In the paper the results of the study of the influence of clinoptilolite concentration, shear stress and temperature on the effective viscosity, shear rate and activation energy of the viscous flow of nanocomposites based on linear low-density polyethylene were presented. It was shown that the in the composition of the natural mineral contains kaolinite or nanoclay. During the diffusion of macro chains into the interlayer space of nanoclays, the latter decays and the surfactant, exchanged cations or anions, stearates present there, as a result migrate into the polymer matrix and then, as lubricants, improve the flowability of the melt of the nanocomposite. For the first time it was shown that natural minerals of Azerbaijan belong to the number of bifunctional fillers, which contribute to the enhancement of polymer composites and, at the same time, improve the flowability of their melt. Rheological studies were carried out on the MELT FLOW TESTER, CEAST MF50 (INSTRON, Italy) capillary rheometer in the temperature range of 190-250 °C and the load of 2.16 -21.6 kg. The size of the nanoparticles of the composites was determined using the device model of STA PT1600 Linseiz, Germany, which varied from 14 to 110 nm. The nanoparticles of clinoptilolite were obtained in the analytical mill A-11 at the maximum rotor speed of 28,000 rpm. Flow curves of nanocomposites based on linear low density polyethylene and clinoptilolite were determined. It was established that introduction of 5% wt. clinoptilolite promotes an increase in shear rate 2.62 times. The results of the study of the influence of clinoptilolite concentration on the rheological and physico-mechanical characteristics of nanocomposites were presented. It was shown that when the concentration of clinoptilolite in the polymer matrix increases from 5 to 15 wt% the shear rate is somewhat reduced, but remains higher than that of the initial polyolefin.For citation:Kakhramanov N.T., Koseva N.S., Kurbanova R.V., Bayramova I.V., Arzumanova N.B., Ismailzade A.C. Rheological characteristics of nanocomposites based on clinoptilolite and linear polyethylene of low density. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 105-112 

A Comparison of Rheological Models and Experimental Data of Metallocene Linear Low Density Polyethylene Solutions as a Function of Temperature and Concentration

2016 ◽  
Vol 12 (3) ◽  
pp. 4322-4339
Author(s):  
Salah Hamza
Keyword(s):  
Experimental Data ◽  
Shear Rate ◽  
Rheological Properties ◽  
Power Law ◽  
Low Density Polyethylene ◽  
Effect Of Temperature ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Shear Rates ◽  
Wide Range

Knowledge of rheological properties of polymer and their variation with temperature and concentration have been globally important for processing and fabrication of polymers in order to make useful products. Basheer et al. [1] investigated, experimentally, the changes in rheological properties of metallocene linear low density polyethylene (mLLDPE) solutions by using a rotational rheometer model AR-G2 with parallel plate geometry. Their work covered the temperature range from  to  and  concentration from  to . In this paper, we reconsider Basheer work to describe the rheological behavior of mLLDPE solutions and its dependence on concentration and temperature.Until now, several models have been built to describe the complex behavior of polymer fluids with varying degrees of success. In this article, Oldroyd 4-constant, Giesekus and Power law models were tested for investigating the viscosity of mLLDPE solution as a function of shear rate. Results showed that Giesekus and power law models provide the best prediction of viscosity for a wide range of shear rates at constant temperature and concentration. Therefore, Giesekus and power law models were suitable for all mLLDPE solutions while Oldroyd 4-constant model doesn't.A new proposed correlation for the viscosity of mLLDPE solutions as a function of shear rate, temperature and concentration has been suggested. The effect of temperature and concentration can be adequately described by an Arrhenius-type and exponential function respectively. The proposed correlation form was found to fit the experimental data adequately.

Linear low‐density polyethylene/high‐density polyethylene blends: Effect of high‐density polyethylene content on die swell and flow instability

2020 ◽  
Vol 138 (9) ◽  
pp. 49910
Author(s):  
Daniel M. G. Freitas ◽  
Akidauana D. B. Oliveira ◽  
Amanda M. Alves ◽  
Shirley N. Cavalcanti ◽  
Pankaj Agrawal ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Flow Instability ◽  
High Density ◽  
Low Density Polyethylene ◽  
Die Swell ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Polyethylene Blends

Analysis and testing of polymer matrix composites with thermoplastic liners having enhanced chemical resistance

2017 ◽  
Vol 36 (20) ◽  
pp. 1487-1502
Author(s):  
Luke P Djukic ◽  
Manudha T Herath ◽  
Daniel C Rodgers ◽  
Roderick Sweeting ◽  
Honesto Buendia
Keyword(s):  
Polymer Matrix ◽  
Chemical Resistance ◽  
Polymer Matrix Composites ◽  
Polyethylene Liner ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Matrix Composites ◽  
Linear Low Density Polyethylene ◽  
Dangerous Goods ◽  
Steel Tanks

Polymer matrix composite tanks offer major advantages to the transport industry in terms of increased payload and corrosion resistance compared to conventional steel tanks. Chemical resistance and versatility can be enhanced through the addition of a thermoplastic liner. This paper presents the results of chemical conditioning, testing and analysis of a linear low-density polyethylene liner, on its own and supported by carbon fiber reinforced polymer. Results are compared to ADR (European Agreement Concerning the International Carriage of Dangerous Goods by Road) requirements. The linear low-density polyethylene liner was tested in combination with 12–15% sodium hypochlorite and 98% sulphuric acid. The results indicate that the liner is suitable for service in tanks transporting these two chemicals. Liners were conditioned at 50℃ for periods of 1000 or 2000 h. Shore D hardness tests and three-point bend tests were performed, compared to unconditioned benchmarks, and found to pass ADR requirements. Finite element models were validated and used to facilitate understanding of the failure of the laminates. Predictions indicate that failure load increases with increased liner modulus, yield stress, and thickness. The models also indicate that the laminate strength and modulus is not significantly changed during chemical conditioning for the stated chemicals.

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