Validation of the Use of SEBS Blends as a Substitute for Liquid Silicone Rubber in Injection Processes

Liquid silicone rubber is an interesting material at an industrial level, but there are great difficulties in the design and machining of molds, and in addition, it cannot be processed using conventional equipment. Therefore, new lines of research have focused on the search for new materials capable of providing final properties similar to liquid silicone rubber, that can also be engineered using simple, conventional processes and machinery. In this investigation, a range of compatible blends, based on two commercial grades of styrene-b-ethyleneco- butylene-b-styrene (SEBS) thermoplastic elastomer, was studied in order to obtain a range of different Shore A hardness blends for industrial applications where liquid silicone rubber (different hardness) is currently used. The two blended elastomers used had widely differing Shore A hardness values (5 and 90). Once the blended materials had been characterized, the Cross and Williams et al. [20] (Cross-WLF) mathematical model was applied in order to obtain theoretical performance curves for the viscosity of each of the blends. After this, a model was developed using the Computer Aided Engineering (CAE) software package Autodesk Moldflow 2012TM. This computer modeling validated the results obtained from the mathematical models, thus making available to process engineers the full range of hardnesses necessary for industrial products (where liquid silicone rubber is used), while still providing the advantages of thermoplastic injection molding.The authors wish to thank "Ministerio de Ciencia e Innovacion" IPT-310000-2010-37 and Universidad Politecnica de Valencia PAID 10012 for their financial support.Juárez Varón, D.; R. Balart; T. Boronat; Reig Pérez, MJ.; Ferrándiz Bou, S. (2013). Validation of the Use of SEBS Blends as a Substitute for Liquid Silicone Rubber in Injection Processes. Materials and Manufacturing Processes. 28(11):1215-1221. doi:10.1080/10426914.2013.811732S121512212811Zhang, B., Wong, J. S.-P., Shi, D., Yam, R. C.-M., & Li, R. K.-Y. (2010). Investigation on the mechanical performances of ternary nylon 6/SEBS elastomer/nano-SiO2hybrid composites with controlled morphology. Journal of Applied Polymer Science, 115(1), 469-479. doi:10.1002/app.30185Su, F.-H., & Huang, H.-X. (2009). Mechanical and rheological properties of PP/SEBS/OMMT ternary composites. Journal of Applied Polymer Science, 112(5), 3016-3023. doi:10.1002/app.29875Sugimoto, M., Sakai, K., Aoki, Y., Taniguchi, T., Koyama, K., & Ueda, T. (2009). Rheology and morphology change with temperature of SEBS/hydrocarbon oil blends. Journal of Polymer Science Part B: Polymer Physics, 47(10), 955-965. doi:10.1002/polb.21699Jose, A. J., Alagar, M., & P. Thomas, S. (2012). Preparation and Characterization of Organoclay Filled Polysulfone Nanocomposites. Materials and Manufacturing Processes, 27(3), 247-254. doi:10.1080/10426914.2011.585490Ivanović, N., Marjanović, N., Grbović Novaković, J., Manasijević, M., Rakočević, Z., Andrić, V., & Hadžić, B. (2009). Experimental and Theoretical Investigations of Cured and Uncured Disiloxane Bisbenzocyclobutene Thin Films. Materials and Manufacturing Processes, 24(10-11), 1180-1184. doi:10.1080/10426910902978811Perisić, M., Radojević, V., Uskoković, P. S., Stojanović, D., Jokić, B., & Aleksić, R. (2009). Wood–Thermoplastic Composites Based on Industrial Waste and Virgin High-Density Polyethylene (HDPE). Materials and Manufacturing Processes, 24(10-11), 1207-1213. doi:10.1080/10426910903032212Iqbal, H., Sheikh, A. K., Al-Yousef, A., & Younas, M. (2012). Mold Design Optimization for Sand Casting of Complex Geometries Using Advance Simulation Tools. Materials and Manufacturing Processes, 27(7), 775-785. doi:10.1080/10426914.2011.648250Özek, C., & Çelık, Y. H. (2011). Calculating Molding Parameters in Plastic Injection Molds with ANN and Developing Software. Materials and Manufacturing Processes, 27(2), 160-168. doi:10.1080/10426914.2011.560224Hirschmanner, M., Mörwald, K., & Fröhlich, C. (2011). Next Generation Mold Level Control: Development of LevCon 2.0. Materials and Manufacturing Processes, 26(1), 169-174. doi:10.1080/10426910903206691Selvakumar, P., & Bhatnagar, N. (2009). Studies on Polypropylene/Carbon Fiber Composite Foams by Nozzle-Based Microcellular Injection Molding System. Materials and Manufacturing Processes, 24(5), 533-540. doi:10.1080/10426910902742738Gramegna, N., Corte, E. D., & Poles, S. (2011). Manufacturing Process Simulation for Product Design Chain Optimization. Materials and Manufacturing Processes, 26(3), 527-533. doi:10.1080/10426914.2011.564248Marković, G., Radovanović, B., Marinović-Cincović, M., & Budinski-Simendić, J. (2009). The Effect of Accelerators on Curing Characteristics and Properties of Natural Rubber/Chlorosulphonated Polyethylene Rubber Blend. Materials and Manufacturing Processes, 24(10-11), 1224-1228. doi:10.1080/10426910902967087Mehat, N. M., & Kamaruddin, S. (2011). Investigating the Effects of Injection Molding Parameters on the Mechanical Properties of Recycled Plastic Parts Using the Taguchi Method. Materials and Manufacturing Processes, 26(2), 202-209. doi:10.1080/10426914.2010.529587Chen, C.-C., Su, P.-L., Chiou, C.-B., & Chiang, K.-T. (2011). Experimental Investigation of Designed Parameters on Dimension Shrinkage of Injection Molded Thin-Wall Part by Integrated Response Surface Methodology and Genetic Algorithm: A Case Study. Materials and Manufacturing Processes, 26(3), 534-540. doi:10.1080/10426914.2010.530331Martinez, A., Castany, J., & Aisa, J. (2011). Characterization of In-Mold Decoration Process and Influence of the Fabric Characteristics in This Process. Materials and Manufacturing Processes, 26(9), 1164-1172. doi:10.1080/10426914.2010.536934Primo Benitez-Rangel, J., Trejo-Hernández, M., Alberto Morales-Hernández, L., & Domínguez-González, A. (2010). Improvement of the Injection Mold Process by Using Vibration Through a Mold Accessory. Materials and Manufacturing Processes, 25(7), 577-580. doi:10.1080/10426910903124902Chen, C.-C. (2011). Design of Effective Parameters on the Wick-Debinding Process for Powder Injection Molded Green Compact. Materials and Manufacturing Processes, 26(10), 1261-1268. doi:10.1080/10426914.2010.544826Boronat, T., Segui, V. J., Peydro, M. A., & Reig, M. J. (2009). Influence of temperature and shear rate on the rheology and processability of reprocessed ABS in injection molding process. Journal of Materials Processing Technology, 209(5), 2735-2745. doi:10.1016/j.jmatprotec.2008.06.013Cross, M. M. (1965). Rheology of non-Newtonian fluids: A new flow equation for pseudoplastic systems. Journal of Colloid Science, 20(5), 417-437. doi:10.1016/0095-8522(65)90022-xReig, M. J., Segui, V. J., & Zamanillo, J. D. (2005). Rheological Behavior Modeling of Recycled ABS/PC Blends Applied to Injection Molding Process. Journal of Polymer Engineering, 25(5). doi:10.1515/polyeng.2005.25.5.43

Study and analysis of injection molding of thermoplastic polymeric materials

[EN] This article aims at analyzing the injection molding of thermoplastic polymeric materials by examining their current situation from the perspective of industrial production, the evolution of technology and modeling of the injection process.[ES] El presente artículo tiene como objetivo el análisis del moldeo por inyección de materiales poliméricos termoplásticos, estudiando su situación actual desde la perspectiva de la producción industrial, la evolución de la técnica y la modelización del proceso de inyección.Authors thank “Ministerio de Ciencia y Tecnología”, Ref: DPI2007-66849-C02-02 and Generalitat Valenciana FPA/2010/027 for financial support.Juárez Varón, D.; Balart, R.; Peydro, MA.; Ferrándiz Bou, S. (2012). Estudio y análisis del moldeo por inyección de materiales poliméricos termoplásticos. 3c Tecnologia. (3):40-53. http://hdl.handle.net/10251/33135S4053

Runtime-guided management of stacked DRAM memories in task parallel programs

Stacked DRAM memories have become a reality in High-Performance Computing (HPC) architectures. These memories provide much higher bandwidth while consuming less power than traditional off-chip memories, but their limited memory capacity is insufficient for modern HPC systems. For this reason, both stacked DRAM and off-chip memories are expected to co-exist in HPC architectures, giving raise to different approaches for architecting the stacked DRAM in the system. This paper proposes a runtime approach to transparently manage stacked DRAM memories in task-based programming models. In this approach the runtime system is in charge of copying the data accessed by the tasks to the stacked DRAM, without any complex hardware support nor modifications to the application code. To mitigate the cost of copying data between the stacked DRAM and the off-chip memory, the proposal includes an optimization to parallelize the copies across idle or additional helper threads. In addition, the runtime system is aware of the reuse pattern of the data accessed by the tasks, and can exploit this information to avoid unworthy copies of data to the stacked DRAM. Results on the Intel Knights Landing processor show that the proposed techniques achieve an average speedup of 14% against the state-of-the-art library to manage the stacked DRAM and 29% against a stacked DRAM architected as a hardware cache.This work has been supported by the RoMoL ERC Advanced Grant (GA 321253), by the European HiPEAC Network of Excellence, by the Spanish Ministry of Economy and Competitiveness (contract TIN2015-65316-P), by the Generalitat de Catalunya (contracts 2014-SGR-1051 and 2014-SGR-1272) and by the European Union’s Horizon 2020 research and innovation programme (grant agreement 779877). M. Moreto has been partially supported by the Spanish Ministry of Economy, Industry and Competitiveness under Ramon y Cajal fellowship number RYC-2016-21104.Peer ReviewedPostprint (author's final draft

The use of wet-laid techniques to obtain flax nonwovens with different thermoplastic binding fibers for technical insulation applications

[EN] In this work, the wet-laid technique has been used to obtain flax nonwovens thermally bonded with different contents of polyvinyl alcohol (PVA) and bicomponent polyamide 6/copolyamide (PA6/CoPA) fibers in the 10-30 wt.% range. Scanning electron microscopy has been used to evaluate the formation of interlock points through melted polymer and flax fibers. Volume porosity has been estimated through determination of thickness and surface mass. Tensile strength and elongation at break have been determined on longitudinal (preferential) and transversal directions to evaluate anisotropy. The sound absorption properties of stacked sheets of flax: PVA and flax: PA6/CoPA nonwovens have been evaluated. In addition, the thermal insulating properties of individual nonwovens have been obtained. Mechanical characterization shows slight anisotropy. The absorption coefficient is interesting in the medium frequencies range, and relatively low thermal conductivity and thermal resistance values are obtained with these nonwovens (in the 0.020-0.025Wm(-1) K-1 range for flax: PVA nonwovens and in the 0.09-0.10Wm(-1) K-1 range for flax: PA6/CoPA nonwovens). By taking into account these features, these nonwoven substrates could find interesting applications as sound absorbers and/or thermal insulation materials in technical applications.This work is part of the project IPT-310000-2010-037, "ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character", and was supported by the "Ministerio de Ciencia e Innovacion", with a grant of (sic)189,540.20, within the Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011 and funded by the European Union through FEDER funds, Technology Fund 2007-2013 and Operational Programme on R + D + i for and on behalf of the companies. The project is also known as "WET-TEX: Implementacion de la tecnologia wet-laid en el desarrollo de nuevos textiles medico-sanitario" with expedient number IMIDIC/2010/137 (total grant of (sic)284,400) and the project "WET-TEX II: Implementacion de la tecnologia wet-laid en la investigacion y desarrollo de paneles para aplicaciones tecnicas a partir de residuos procedentes de la industria textil" with expedient number IMDEEA/2011/167 (total grant of (sic)255,000) funded by IMPIVA and cofunded (80%) by the European Union through FEDER funds, Valencian Community Operational 2007-2012.Fages, E.; Cano, MA.; Gironés, S.; Boronat Vitoria, T.; Fenollar Gimeno, OÁ.; Balart Gimeno, RA. (2013). The use of wet-laid techniques to obtain flax nonwovens with different thermoplastic binding fibers for technical insulation applications. Textile Research Journal. 83(4):426-437. https://doi.org/10.1177/0040517512454183S42643783

Higher Dimensional Cosmology with Some Dark Energy Models in Emergent, Logamediate and Intermediate Scenarios of the Universe

We have considered N-dimensional Einstein field equations in which four-dimensional space-time is described by a FRW metric and that of extra dimensions by an Euclidean metric. We have chosen the exponential forms of scale factors a and d numbers of b in such a way that there is no singularity for evolution of the higher dimensional Universe. We have supposed that the Universe is filled with K-essence, Tachyonic, Normal Scalar Field and DBI-essence. Here we have found the nature of potential of different scalar field and graphically analyzed the potentials and the fields for three scenario namely Emergent Scenario, Logamediate Scenario and Intermediate Scenario. Also graphically we have depicted the geometrical parameters named statefinder parameters and slow-roll parameters in the higher dimensional cosmology with the above mentioned scenarios.Comment: 21 pages, 36 figure

Use of atmospheric plasma treatment to improve adhesion properties of sodium ionomer sheets

“NOTICE: this is the author’s version of a work that was accepted for publication in Surface and Coatings Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Surface and Coatings Technology, [VOL 218, (MAR 15 2013)] DOI10.1016/j.surfcoat.2012.12.016¨[EN] Polyolefins are characterized by having a low surface energy due to their non-polar nature, in the case of some ionomers, the base component is a polyolefin, thus relative poor adhesion properties are expected. As is widely known, for many industrial applications, such as coatings, paintings and formation of adhesive bonds, a high surface energy is required in order to provide good surface adhesion; for this reason the use of ionomers in these applications requires a previous surface treatment. In this paper surface treatment by atmospheric plasma has been used to provide surface activation to polyolefin-based sodium ionomers in order to improve their low intrinsic adhesion properties. This work has focused on the analysis of the influence of main process variables such as treatment rate and distance between nozzle and substrate to observe the improvement of adhesion properties at ionomer-polycarbonate adhesion joints subjected to shear and T-peel tests. After plasma treatment, T-peel force has increased six times it original value at most aggressive plasma parameters. Regarding on shear force, at same aggressive conditions of plasma treatment we achieved an increase of ten times its value of the shear sample without surface treatment, and its phenomenon can be seen in SEM pictures. (C) 2012 Elsevier B.V. All rights reserved.This work is part of the project IPT-310000-2010-037, "ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character" funded by the "Ministerio de Ciencia e Innovacion", with an aid of 189540.20 euros, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e InnovacionTecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, Operational Programme on R + D + i for and on behalf of the companies. Also Generalitat Valenciana ref.: ACOMP/2012/087 is acknowledged for financial support. J.M. Espana wants to thank the Polytechnic University of Valencia (UPV) for their financial support through an FPI-UPV grant.España Giner, JM.; Boronat Vitoria, T.; García Sanoguera, D.; López Martínez, J.; Balart Gimeno, RA. (2013). Use of atmospheric plasma treatment to improve adhesion properties of sodium ionomer sheets. Surface and Coatings Technology. 218:1-6. https://doi.org/10.1016/j.surfcoat.2012.12.016S1621

Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides

In this work we have developed polymeric materials from epoxidized vegetable oils in order to obtain materials with excellent mechanical properties for use as green matrix composites. Epoxidized soybean oil (ESO), epoxidized linseed oil (ELO) and different mixtures of the two oils were used to produce the polymers. Phthalic anhydride (17 mol%) and maleic anhydride (83 mol%) which has a eutectic reaction temperature of 48 °C were used as crosslinking agents while benzyl dimethyl amine (BDMA) and ethylene glycol were used as the catalyst and initiator, respectively. The results showed that samples 100ELO and 80ELO20ESO could be used as a matrix in green composites because they demonstrated good mechanical properties. © 2012 AOCS (outside the USA).This work is part of the project IPT-310000-2010-037,''ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character'' funded by the "Ministerio de Ciencia e Innovacion", with financial aid of 189,540.20 EUR, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, Operational Programme on R + D + i for and on behalf of the companies.Samper Madrigal, MD.; Fombuena Borrás, V.; Boronat Vitoria, T.; García Sanoguera, D.; Balart Gimeno, RA. (2012). Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides. Journal of the American Oil Chemists' Society. 89(8):1521-1528. https://doi.org/10.1007/s11746-012-2041-yS15211528898Averous L (2004) Biodegradable multiphase systems based on plasticized starch: a review. J Macromol Sci Polym Rev C44:231–274Bledzki AK, Jaszkiewicz A (2010) Mechanical performance of biocomposites based on PLA and PHBV reinforced with natural fibres—a comparative study to PP. Compos Sci Technol 70:1687–1696Raquez JM, Deleglise M, Lacrampe MF, Krawczak P (2010) Thermosetting (bio)materials derived from renewable resources: a critical review. Prog Polym Sci 35:487–509Charlet K, Jernot JP, Gomina M, Bizet L, Breard J (2010) Mechanical properties of flax fibers and of the derived unidirectional composites. J Compos Mater 44:2887–2896Barreto ACH, Esmeraldo MA, Rosa DS, Fechine PBA, Mazzetto SE (2010) Cardanol biocomposites reinforced with jute fiber: microstructure, biodegradability, and mechanical properties. Polym Compos 31:1928–1937Thakur VK, Singha AS (2010) Physico-chemical and mechanical characterization of natural fibre reinforced polymer composites. Iran Polym J 19:3–16Schmitz WR, Wallace JG (1954) Epoxidation of methyl oleate with hydrogen peroxide. J Am Oil Chem Soc 31:363–365La Scala J, Wool RP (2002) Effect of FA composition on epoxidation kinetics of TAG. J Am Oil Chem Soc 79:373–378de Espinosa LM, Ronda JC, Galia M, Cadiz V (2008) A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources. J Polym Sci Pol Chem 46:6843–6850Gerbase AE, Petzhold CL, Costa APO (2002) Dynamic mechanical and thermal behavior of epoxy resins based on soybean oil. J Am Oil Chem Soc 79:797–802Boquillon N, Fringant C (2000) Polymer networks derived from curing of epoxidised linseed oil: influence of different catalysts and anhydride hardeners. Polymer 41:8603–8613Montserrat S, Flaque C, Calafell M, Andreu G, Malek J (1995) Influence of the accelerator concentration on the curing reaction of an epoxy-anhydride system. Thermochim Acta 269:213–229Zacharuk M, Becker D, Coelho LAF, Pezzin SH (2011) Study of the reaction between polyethylene glycol and epoxy resins using N,N-dimethylbenzylamine as catalyst. Polimeros 21:73–77Lozada Z, Suppes GJ, Tu YC, Hsieh FH (2009) Soy-based polyols from oxirane ring opening by alcoholysis reaction. J Appl Polym Sci 113:2552–256