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Sousa GS, da Silva GDAS, d'Almeida JRM. Influence of soapstone waste on the mechanical and rheological properties of high‐density polyethylene. J Appl Polym Sci 2021. [DOI: 10.1002/app.50966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Giulia Simão Sousa
- Department of Chemical and Materials Engineering Pontifical Catholic University of Rio de Janeiro Rio de Janeiro Brazil
| | | | - José Roberto Moraes d'Almeida
- Department of Chemical and Materials Engineering Pontifical Catholic University of Rio de Janeiro Rio de Janeiro Brazil
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2
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Wojas NA, Dobryden I, Wallqvist V, Swerin A, Järn M, Schoelkopf J, Gane PAC, Claesson PM. Nanoscale Wear and Mechanical Properties of Calcite: Effects of Stearic Acid Modification and Water Vapor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9826-9837. [PMID: 34355909 PMCID: PMC8397405 DOI: 10.1021/acs.langmuir.1c01390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Understanding the wear of mineral fillers is crucial for controlling industrial processes, and in the present work, we examine the wear resistance and nanomechanical properties of bare calcite and stearic acid-modified calcite surfaces under dry and humid conditions at the nanoscale. Measurements under different loads allow us to probe the situation in the absence and presence of abrasive wear. The sliding motion is in general characterized by irregular stick-slip events that at higher loads lead to abrasion of the brittle calcite surface. Bare calcite is hydrophilic, and under humid conditions, a thin water layer is present on the surface. This water layer does not affect the friction force. However, it slightly decreases the wear depth and strongly influences the distribution of wear particles. In contrast, stearic acid-modified surfaces are hydrophobic. Nevertheless, humidity affects the wear characteristics by decreasing the binding strength of stearic acid at higher humidity. A complete monolayer coverage of calcite by stearic acid results in a significant reduction in wear but only a moderate reduction in friction forces at low humidity and no reduction at 75% relative humidity (RH). Thus, our data suggest that the wear reduction does not result from a lowering of the friction force but rather from an increased ductility of the surface region as offered by the stearic acid layer. An incomplete monolayer of stearic acid on the calcite surface provides no reduction in wear regardless of the RH investigated. Clearly, the wear properties of modified calcite surfaces depend crucially on the packing density of the surface modifier and also on the air humidity.
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Affiliation(s)
- Natalia A. Wojas
- Bioeconomy
and Health Division, Department of Materials and Surface Design, RISE Research Institutes of Sweden, Box 5607, SE-114 86 Stockholm, Sweden
- Division
of Surface Chemistry and Corrosion Science, Department of Chemistry,
School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
| | - Illia Dobryden
- Division
of Surface Chemistry and Corrosion Science, Department of Chemistry,
School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
- Division
of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE−971 87 Luleå, Sweden
| | - Viveca Wallqvist
- Bioeconomy
and Health Division, Department of Materials and Surface Design, RISE Research Institutes of Sweden, Box 5607, SE-114 86 Stockholm, Sweden
| | - Agne Swerin
- Department
of Engineering and Chemical Sciences: Chemical Engineering, Faculty
of Health, Science and Technology, Karlstad
University, SE-651 88 Karlstad, Sweden
| | - Mikael Järn
- Bioeconomy
and Health Division, Department of Materials and Surface Design, RISE Research Institutes of Sweden, Box 5607, SE-114 86 Stockholm, Sweden
| | | | - Patrick A. C. Gane
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O.
Box 16300, FI-00076 Aalto, Finland
| | - Per M. Claesson
- Bioeconomy
and Health Division, Department of Materials and Surface Design, RISE Research Institutes of Sweden, Box 5607, SE-114 86 Stockholm, Sweden
- Division
of Surface Chemistry and Corrosion Science, Department of Chemistry,
School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
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Kalantar Mehrjerdi A, Åkesson D, Skrifvars M. Influence of talc fillers on bimodal polyethylene composites for ground heat exchangers. J Appl Polym Sci 2020. [DOI: 10.1002/app.49290] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Adib Kalantar Mehrjerdi
- Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business University of Borås Borås Sweden
| | - Dan Åkesson
- Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business University of Borås Borås Sweden
| | - Mikael Skrifvars
- Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business University of Borås Borås Sweden
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Kalantar Mehrjerdi A, Bashir T, Skrifvars M. Melt rheology and extrudate swell properties of talc filled polyethylene compounds. Heliyon 2020; 6:e04060. [PMID: 32490251 PMCID: PMC7260442 DOI: 10.1016/j.heliyon.2020.e04060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 02/14/2020] [Accepted: 05/20/2020] [Indexed: 11/01/2022] Open
Abstract
An experimental study of high-density polyethylene (HDPE) composites filled with talc (0-15 wt.%) was carried out to investigate the rheological properties. The apparent melt viscosity, melt density, and die-swell ratio (B) of the composites were measured at constant shear stress and constant shear rate by using a melt flow indexer and capillary rheometer. The experimental conditions were set to a temperature range from 190 to 220 °C for both apparatuses whereas a load range from 5 to 12.16 kg was selected for melt flow indexer and shear rate range from 1 to 10000 s-1 for capillary rheometer. The initial study showed that the talc particulates did not influence the melt viscosity compared with the neat HDPE but decreased the elasticity of the polymer system. The HDPE/talc systems obeyed power-law model in shear stress-shear rate variations and were shear thinning, meanwhile, the die-swell increased with an increased wall shear rate and shear stress. The melt density of the composites increased linearly with an increase of the filler weight fraction and decreased with the increase of the testing temperature. The talc-HDPE composites showed compressible in the molten state.
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Affiliation(s)
| | - Tariq Bashir
- Swedish Centre for Resource Recovery, University of Borås, 501 90 Borås, Sweden
| | - Mikael Skrifvars
- Swedish Centre for Resource Recovery, University of Borås, 501 90 Borås, Sweden
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Ajorloo M, Ghodrat M, Moghbeli MR, Kang WH. A statistical approach to investigate the effects of multicomponent fractions on the mechanical properties of PP/PPMA/Talc/POE composites. JOURNAL OF POLYMER RESEARCH 2020. [DOI: 10.1007/s10965-020-2042-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Elshereksi NW, Ghazali M, Muchtar A, Azhari CH. Review of titanate coupling agents and their application for dental composite fabrication. Dent Mater J 2017; 36:539-552. [PMID: 28652551 DOI: 10.4012/dmj.2016-014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Silane is a dominant coupler that is widely used in dentistry to promote adhesion among the components of dental composites. Silica-based fillers can be easily silanized because of their similarly ordered structure. However, silane is hydrolytically degraded in the aqueous oral environment and inefficiently bonds to non-silica fillers. Thus, the development of hydrolytically stable dental composites is an important objective in the research on dental materials. Titanate coupling agents (TCAs) exhibit satisfactory interfacial bonding, enhanced homogeneous filler dispersion, and improved mechanical properties of the composites. Titanates also provide superior hydrolytic stability in wet environments, which should be considered in fabricating dental composites. The addition of a small amount of titanates can improve the resistance of the composites to moisture. This paper reviews the effects of the instability of silanes in moisture on the performance of dental composites and presents TCAs as alternative couplers to silanes for fabricating dental composites.
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Affiliation(s)
- Nidal Wanis Elshereksi
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia.,Department of Dental Technology, College of Medical Technology
| | - Mariyam Ghazali
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia
| | - Andanastuti Muchtar
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia
| | - Che Husna Azhari
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia
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Lu Y, Zhang W, Li X, Xu S. Synthesis of new polyether titanate coupling agents with different polyethyleneglycol segment lengths and their compatibilization in calcium sulfate whisker/poly(vinyl chloride) composites. RSC Adv 2017. [DOI: 10.1039/c7ra03692b] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CSW modified by coupling agent and the interfacial interaction between mCSW and PVC matrix.
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Affiliation(s)
- Yunhua Lu
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
- China
| | - Weipeng Zhang
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
- China
| | - Xingwei Li
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
- China
| | - Shiai Xu
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
- China
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Elshereksi NW, Ghazali MJ, Muchtar A, Azhari CH. Studies on the effects of titanate and silane coupling agents on the performance of poly (methyl methacrylate)/barium titanate denture base nanocomposites. J Dent 2016; 56:121-132. [PMID: 27916635 DOI: 10.1016/j.jdent.2016.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/07/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022] Open
Abstract
OBJECTIVES This study aimed to fabricate and characterise silanated and titanated nanobarium titanate (NBT) filled poly(methyl methacrylate) (PMMA) denture base composites and to evaluate the behaviour of a titanate coupling agent (TCA) as an alternative coupling agent to silane. The effect of filler surface modification on fracture toughness was also studied. METHODS Silanated, titanated and pure NBT at 5% were incorporated in PMMA matrix. Neat PMMA matrix served as a control. NBT was sonicated in MMA prior to mixing with the PMMA. Curing was carried out using a water bath at 75°C for 1.5h and then at 100°C for 30min. NBT was characterised via Fourier transform-infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis before and after surface modification. The porosity and fracture toughness of the PMMA nanocomposites (n=6, for each formulation and test) were also evaluated. RESULTS NBT was successfully functionalised by the coupling agents. The TCA exhibited the lowest percentage of porosity (0.09%), whereas silane revealed 0.53% porosity. Statistically significant differences in fracture toughness were observed among the fracture toughness values of the tested samples (p<0.05). While the fracture toughness of untreated samples was reduced by 8%, an enhancement of 25% was achieved after titanation. In addition, the fracture toughness of the titanated samples was higher than the silanated ones by 10%. CONCLUSION Formation of a monolayer on the surface of TCA enhanced the NBT dispersion, however agglomeration of silanated NBT was observed due to insufficient coverage of NBT surface. Such behaviour led to reducing the porosity level and improving fracture toughness of titanated NBT/PMMA composites. Thus, TCA seemed to be more effective than silane. CLINICAL SIGNIFICANCE Minimising the porosity level could have the potential to reduce fungus growth on denture base resin to be hygienically accepTable Such enhancements obtained with Ti-NBT could lead to promotion of the composites' longevity.
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Affiliation(s)
- Nidal W Elshereksi
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia; Department of Dental Technology, College of Medical Technology, P.O. Box: 1458 Misurata, Libya
| | - Mariyam J Ghazali
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
| | - Andanastuti Muchtar
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
| | - Che H Azhari
- Department of Mechanical & Materials Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia.
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