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Article
Publication date: 17 February 2021

Liangwei Qiu, Xiaoyang Chen and Fakai Dong

This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact…

Abstract

Purpose

This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact under pure rolling.

Design/methodology/approach

By using the relative light intensity method, the film thickness is calculated from the interferometer images which are captured by multiple-contact optical elastohydrodynamic lubricated test rig.

Findings

The test results reveal that polymers, both PMA and PIB, have a significant contribution to the film-forming capability of base oils and the film thickness increases with concentration. The forming-film capabilities for PMA and PIB in base oils are similar at low concentration, while PIB gives a higher film thickness than PMA at high concentration. Shear-thinning phenomenon are observed in all polymer-based oils.

Originality/value

The polymer usually as an additive is added into the low viscosity base oils to improve the properties of lubricant oil. This paper reports the lubricated properties of PMA and PIB with different concentrations in base oils and to evaluate their functional mechanism in a point contact.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0263/

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 February 1995

Sumeet Trehan and M.C. Shukla

The acute shortage coupled with tremendous increase in cost of various solvents used by paint industry and pollution becoming a serious concern has resulted in intensive…

Abstract

The acute shortage coupled with tremendous increase in cost of various solvents used by paint industry and pollution becoming a serious concern has resulted in intensive study of water‐borne coatings. Water‐borne coatings ideally meet the needs for coating systems which do not cause atmospheric pollutions and at the same time help in conservation of precious and renewable petroleum resources. Many research workers have developed water‐soluble epoxies, alkyds and acrylics to make water‐based surface coatings.

Details

Pigment & Resin Technology, vol. 24 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 20 March 2009

Nesrine Kassem and Abd‐Alla M.A. Nada

The purpose of this paper is to study the effect of treatment using hydrophilic and hydrophobic polymers on mechanical properties and/or water absorption of paper sheets.

Abstract

Purpose

The purpose of this paper is to study the effect of treatment using hydrophilic and hydrophobic polymers on mechanical properties and/or water absorption of paper sheets.

Design/methodology/approach

Paper sheets produced from paper grade wood pulp were dipped in polyacrylamide (PAA), polymethylmethacrylate (PMM) and polyvinyl alcohol (PVA) polymer solutions, respectively. The effects of using different polymer solutions (PAA, PMM and PVA), as well as the effects of dipping time (1, 5 and 10 min) and concentration of polymer (0.5, 1, 2 and 3 per cent), on the mechanical properties as well as water absorption of paper sheets were investigated.

Findings

It was found that the treatment of paper sheets with different polymer solutions improved mechanical properties as well as water absorption of paper sheets when the polymer concentration was below 1 per cent and the dipping time did not exceed 5 min.

Research limitations/implications

Paper sheets resulting from treatment using hydrophilic polymers can be used as printing papers as the printability improves because water absorption improves, while paper sheets resulting from using hydrophobic polymers can be used for packaging because water adsorption is less and breaking length improved.

Originality/value

Improving some mechanical properties and/or water absorption of paper sheets. The improvement of dipped sheets increased by increasing dipping time till 5 min and by increasing polymer concentration till 1 per cent. Utilisation of PAA led to best results especially when it was hydrolysed.

Details

Pigment & Resin Technology, vol. 38 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 27 May 2014

Bo Zhao

The air drawing model plays an important in spunbonding. The purpose of this paper is to study the influence of the density and the specific heat capacity of polymer melt…

Abstract

Purpose

The air drawing model plays an important in spunbonding. The purpose of this paper is to study the influence of the density and the specific heat capacity of polymer melt at constant pressure changing with polymer temperature on the fiber diameter.

Design/methodology/approach

The air drawing model of the polypropylene polymer in a spunbonding process is presented and solved by introducing the numerical computation results of the air flow field of aerodynamic device.

Findings

The model prediction of the filament fiber diameter coincides well with the experimental data. The effects of the processing parameters on the filament fiber diameter are discussed. A lower polymer throughput rate, higher polymer melt temperature, higher primary air temperature, higher venturi gap, higher air suction speed, and higher quench pressure can all produce finer filament fiber.

Originality/value

The experimental results show that the agreement between the results and experimental data are very better, which verifies the reliability of these models. The results show great prospects for this research in the field of computer assisted design of spunbonding technology.

Details

International Journal of Clothing Science and Technology, vol. 26 no. 2
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 20 June 2008

H. Unal and F. Findik

The present study aims to find out the best polymer/polymer pair in electrical insulating applications. Moreover, the effects of different polymer counterpart and applied…

Abstract

Purpose

The present study aims to find out the best polymer/polymer pair in electrical insulating applications. Moreover, the effects of different polymer counterpart and applied load on the friction and wear behaviour of PA 46 + 30%GFR and unfilled PA 66 thermoplastic polymers are to be studied.

Design/methodology/approach

Friction and wear tests vs PA 46 + 30%GFR and PPS + 30%GFR polymer composites were carried out on a pin‐on‐disc arrangement and at a dry sliding conditions. Tribological tests were performed at room temperature under 20, 40 and 60 N loads and at 0.5 m/s sliding speed.

Findings

The results showed that, the coefficient of friction decreases with the increasing of load (up to 40 N) for PA 46 + 30%GFR composite and polyamide (PA) 66 polymer used in this study. However, above 40 N applied load the coefficient of friction increases. The specific wear rate for PA 46 + 30%GFR and PA 66 against PPS + 30%GFR polymer composite counterpart are about in the order of 10−13 m2/N while the specific wear rate for PA 46 + 30%GFR and PA 66 against PA 46 + 30%GFR polymer composite counterpart are in the order of 10−14 m2/N. For PA 46 + 30%GFR composite and unfilled PA 66 polymers tested the specific wear rate values increased with the increment of load. The highest specific wear rate is for unfilled PA 66 against PPS + 30%GFR with a value of 2.81 × 10−13 m2/N followed by PA 66 against PA 46 + 30%GFR with a value of 2.26 × 10−13 m2/N. The lowest wear rate is PA 46 + 30%GFR polymer composite against PA 46 + 30%GFR polymer composite counterpart with a value of 3.19 × 10−14 m2/N. The average specific wear rates for unfilled PA 66 against PA 46 + 30%GFR is 80 times higher than PA 46 + 30%GFR wear rate while specific wear rates for unfilled PA 66 against PPS + 30%GFR is 100 times higher than that of PA 46 + 30%GFR wear rate. From point view of tribological performance, PA 46 + 30%GFR is a more suitable engineering thermoplastic composite materials for electrical contact breaker applications.

Research limitations/implications

In the present work, tribological tests were performed only at room temperature under three different loads and a sliding speed. This is the limitation of the work.

Practical implications

This work is easily used for industrial polyamides to check their tribological behaviours.

Originality/value

This is an original and experimental study and it will be useful both for academicians and for industrial sides.

Details

Industrial Lubrication and Tribology, vol. 60 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 November 1998

A.L. Perou and J.M. Vergnaud

Studies are made on food three‐layer packages, where a contaminated recycled polymer layer is located between two virgin polymer layers. As the thick food packages are…

Abstract

Studies are made on food three‐layer packages, where a contaminated recycled polymer layer is located between two virgin polymer layers. As the thick food packages are made by pressing the polymer layers in a mould kept at around the melting temperature of the polymer, the process is thus rather complex with heat transfer and contaminant transfer. Heat transfer is controlled by conduction through the package with a high coefficient of heat transfer in the mould, and conduction through the package and free convection at the surface during the cooling period in motionless air. The contaminant transfer is controlled by diffusion through the polymer with a temperature‐dependent diffusivity. A numerical model taking into account both the heat and mass transfer is built in order to resolve the problem. Various parameters appear of interest, such as the conditions of the processing with the temperature of the mould and time in the mould, the thicknesses of the polymer layers. Two types of sandwich are considered with different thicknesses for each layer. The profiles of concentration of the contaminant are obtained through the polymer packages.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 8 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 8 April 2014

Huseyin Unal, Salih Hakan Yetgin and Fehim Findik

– The purpose of the study was to find the best performance polymer material to be used in railway car bogies.

Abstract

Purpose

The purpose of the study was to find the best performance polymer material to be used in railway car bogies.

Design/methodology/approach

Wear tests and optical and scanning electron microscopy were used.

Findings

The friction coefficients of ultra-high-molecular-weight polyethylene (UHMWPE) and Nylon 6 polymers, as opposed to AISI 4140 steel, reduced with the increment of applied loads. With the increment of sliding speed, the friction coefficient increased in both UHMWPE and Nylon 6 polymers. The specific wear rate of the UHMWPE polymer was determined to be about 10-14 m2/N, whereas the rate of Nylon 6 was determined to be 10-13 m2/N.

Practical implications

The aim of the study was to find the best performance polymer material to be used in railway car bogies.

Originality/value

The friction and wear performance of UHMWPE and Nylon 6 engineering polymers were studied and compared to their AISI 4140 steel counterparts. It is an original work and it is not published in any media.

Details

Industrial Lubrication and Tribology, vol. 66 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 11 April 2020

Abd El-Wahab H., Farouk Abd El-Monem, Naser M.A., Hussain A.I., El-Shahat H.A. Nashy and Lin L.

The purpose of this paper is devoted to application of the emulsion polymer of poly(methyl methacrylate-co-butyl acrylate) prepared with in situ nano-silica as a novel…

Abstract

Purpose

The purpose of this paper is devoted to application of the emulsion polymer of poly(methyl methacrylate-co-butyl acrylate) prepared with in situ nano-silica as a novel tanning agent of hide to partly or totally replace chrome salt and to improve physical, thermal and mechanical properties of the tanned leather and to reduce the environmental impact of chrome tanning effluent.

Design/methodology/approach

Polymer/nano-silica hybrid emulsions were prepared via in situ seed emulsion polymerisation. The prepared polymers were characterised for solid content, molecular weight, viscosity, drying time, minimum film-forming temperature (MFFT) and microstructures (via transmission electron microscopy). The mechanical, thermal and surface morphological (by scanning electron microscope) properties of the treated samples were also investigated. The influences of the increase in the content of organic nano-silica on the properties of the tanned leather are discussed.

Findings

It was found that the viscosity, the particle size and the solid content of the prepared polymers increased as the content of the nano-silica increased while gloss and drying time of the resulting polymer film decreased. Tanning buffalo hide by Polymer F (containing a high content of nano-silica) gave desirable properties in terms of tensile strength, thermal stability and shrinkage temperature.

Research limitations/implications

This paper discusses the preparation and the characterisation of emulsion polymers with in situ nano-silica and their application in tanning process to enhance and improve the leather quality, as well as reduce the use of chrome tanning materials and consequently chrome tanning waste.

Practical implications

The tanned leather showed an improvement of physico-mechanical properties and enhancement of thermal stability. Furthermore, the tanned leather has uniform colour, softness and firmness of grain. All these promising results provide evidence to support the applicability of the prepared co-polymer/nano-silica emulsions as an efficient tanning agent that also provides lubricating properties for leather.

Originality/value

Since May 2015, REACH Annex XVII restricts Cr(VI) in leather articles or leather parts of articles that come into contact with skin to a concentration of less than 3 mg/kg. Cases of discovery of Cr(VI) in leather papers have been reported by the European rapid alert system on dangerous consumer products (RAPEX). The emulsion poly (methyl methacrylate-co-butyl acrylate) with in situ nano-silica that has been developed via the study reported in this paper is one of the better technologies for the reduction of chromium ratio used in tanning industry.

Details

Pigment & Resin Technology, vol. 49 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 8 July 2019

Adam Gnatowski and Agnieszka Kijo-Kleczkowska

The main purpose of polymeric mixtures manufacturing is wish to eliminate or reduce drawbacks which polymers are characterised by and also to strive for reduction of the…

Abstract

Purpose

The main purpose of polymeric mixtures manufacturing is wish to eliminate or reduce drawbacks which polymers are characterised by and also to strive for reduction of the price of expensive polymers with particular very precious properties by mixing them with cheaper polymers but without significant deterioration of their properties. In the work some investigation results have been presented for PA6 which is miscible in viscoelastic state with polymer, with ability to create physical bounds with substances of inorganic as well as organic origins. For this purpose, polyvinylpyrrolidone (PVP) has been used with law molecular weight (10 ± 2,5 thousand). The functionalactive material was prepared with sharp tuning sorption ability across physical modification polycapramide mixed from bipolar polyvinylpyrrolidone in batch – free state, which characterises high ability complex. In the paper, some results of chosen properties of PA with the addition of polyvinylpyrrolidone (PVP) have been presented. In chance of mixing PA6 with PVP forms solution PVP in PA6, to which proper are large intermolecular influence, in this case hydrogen bond. It is possible to foresee that under the influences of large tangent stresses and intermolecular interaction colloidal solution PVP in PA forms with sure homogeneity, after cooling of it the inversion of winding phases is not noticeable In the mixtures on the basis of such polymers the intermolecular interactions occur, and they differently influence parameters of the modified materials. Conducted investigations have proved opportunity of physical modification of PA6 during mixing, in viscoelastic state, with polyvinylpyrrolidone. The modified polymer has dielectric properties and a reduced susceptibility to water absorption. It can be used as an insulation material, in all industrial sectors, including the energy sector.

Design/methodology/approach

For examinations, the following mixtures were made out: PA 99%/PVP 1%, PA 98%/PVP 2%, PA 90%/PVP 10%. Making mixtures out was begun with weighing elements out on numerical Sortorius AG GO TTINGEN scales and CAS MODEL: SW-1 (PA, PVP). Next elements of mixture were mixed with themselves mechanically. The process of drying was carried out in the ZELMET drier with the thermal kc-100/200 chamber in the temperature 80 °C for 12 h. The process of mixing up was carried out in the arrangement plasticising injections moulding machine of the voluted KRAUSS MAFFEI company KM 65-1600C1 (D screw = 30 mm and the L = 27D, the nozzle about d = 4 mm and the l = 2d) at the following parameters: is the nozzle temperature 230 °C, the speed of turnovers of the screw 210 obr/min. Granulated product of mixtures were get on the rotor grinder. Samples for examinations were made on the computer-operated injection moulding machine of type of KM 65-1600C1 of the KRAUSS MAFFEI company. The conditions which complement the homogeneity of a mixture – these include mixing processes with high shear stresses with the range of temperatures for viscoelastic state for the individual polymers. Such conditions are met by multiple mixing in the injection machine cylinder with extended perpetual screw length (L/D = 25 ÷ 42). Permanent conditions of injecting samples for the research on physical properties were the following: nozzle temperature – 230°C; worm area I temperature – 190°C; worm area II temperature – 210°C; worm area III temperature – 230-245°C, mould temperature 40°C, injection pressure – 60 MPa, clamping time – 5 s, cooling time – 30 s The research on chosen physical properties of getting polymer materials was carried out: hardnesses on hardness testing machine, impact resistance by Charpy’s method, mechanical properties while tension over the endurance machine the INSTON with tension speed of 90 mm/min, softening point by Vicat’s method was determined using testing machine type HAAKE N8, the investigation of DSC method and DMTA method using testing machine type Netzsch, water absorbing power test. The research on the structure was also carried out on the optical microscope type NIKON ECLIPSE E200.

Findings

In the paper, for the physical modification of PA 6, the polyvinylpyrrolidone (PVP) – amorphous polymer which is capable of ionisation and creation of complexes with the transition of the charge with many electrophilic compounds and also proton donors have been used. PVP does not change into the viscoelastic state but it is easily soluble in organic and inorganic solvents and the best in water. Its characteristic is high sorption capacity. As a result of ionisation changes PVP preserve the conformation changes. In case of mixing of polar PA6 polymers with PVP, a PVP solution is being created in PA, to whom big intermolecular interactions are proper for, in it hydrogen bonds. Reducing of polarity occurs of both polymers as a result of hydrogen bonds in created macromolecules. Macromolecule so they are interfering easily in fused condition creating the mixture about reliable homogeneity. An effect is applying to mixing with PA6 in case of dissolving PVP in the PA6 stop under the influence of big adjacent tensions in screw extruder what is calling changes of the supermolecular structure and properties of the material after chilling of stop in the form during injecting. The resultant homogeneous mixture is marked by one reflex narrowed in comparison with output PA6 of melting visible on DSC thermogram with moving to the page of higher tmmax temperatures. PA6/PVP mixtures are also providing effects of examinations about the homogeneity with DMTA method which shows results that the mixture is marked by one reflex of mechanical losses on the plot from (Tg) from the maximum at bigger than PA6 Tg (about 10 ÷ 15°C), and it is possible at the same time to reason that the mixture has not very thick frictional network as a result of the exchange of intermolecular bonds what is displayed itself in the increase in Tg intensity. The results of investigations show that PA with PVP additions create more stable material with visible homogeneity (due to strong intermolecular interactions) which is characterised by satisfactory mechanical properties which insignificantly differ from PA6 properties, but which shows higher deformability and sorptive power.

Originality/value

The results of investigations show that PA with PVP additions create more stable material with visible homogeneity (due to strong intermolecular interactions) which is characterised by satisfactory mechanical properties which insignificantly differ from PA6 properties, but which shows higher deformability and sorptive power. The modified polymer has dielectric properties and a reduced susceptibility to water absorption. It can be used as an insulation material, in all industrial sectors, including the energy sector.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 8 July 2019

Evgeny Morozov, Mikhail Novikov, Vyacheslav Bouznik and Gleb Yurkov

Active employment of additive manufacturing for scaffolds preparation requires the development of advanced methods which can accurately characterize the morphologic…

Abstract

Purpose

Active employment of additive manufacturing for scaffolds preparation requires the development of advanced methods which can accurately characterize the morphologic structure and its changes during an interaction of the scaffolds with substrate and aqueous medium. This paper aims to use the method of nuclear magnetic resonance (NMR) imaging for preclinical characterization of 3D-printed scaffolds based on novel allyl chitosan biocompatible polymer matrices.

Design/methodology/approach

Biocompatible polymer scaffolds were fabricated via stereolithography method. Using NMR imaging the output quality control of the scaffolds was performed. Scaffolds stability, polymer matrix homogeneity, kinetic of swelling processes, water migration pathways within the 3D-printed parts, effect of post-print UV curing on overall scaffolds performance were studied in details.

Findings

NMR imaging visualization of water uptake and polymer swelling processes during the interaction of scaffolds with aqueous medium revealed the formation of the fronts within the polymer matrices those dynamics is governed by case I transport (Fickian diffusion) of the water into polymer network. No significant difference was observed in front propagation rates along the polymer layers and across the layers stack. After completing the swelling process, the polymer scaffolds retain their integrity and no internal defects were detected.

Research limitations/implications

NMR imaging revealed that post-print UV curing aimed to improve the overall performance of 3D-printed scaffolds might not provide a better quality of the finish product, as this procedure apparently yield strongly inhomogeneous distribution of polymer crosslink density which results in subsequent inhomogeneity of water ingress and swelling processes, accompanied by stress-related cracks formation inside the scaffolds.

Practical implications

This study introduces a method which can successfully complement the standard tests which now are widely used in either additive manufacturing or scaffolds engineering.

Social implications

This work can help to improve the overall performance of the polymer scaffolds used in tissue engineering.

Originality/value

The results of this study demonstrate feasibility of NMR imaging for preclinical characterization of 3D printed biocompatible polymer scaffolds. The results are believed to contribute to better understanding of the processes vital for improving the design of 3D-printed polymer scaffolds.

Details

Rapid Prototyping Journal, vol. 25 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

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