{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,1]],"date-time":"2025-11-01T23:25:44Z","timestamp":1762039544363,"version":"build-2065373602"},"reference-count":52,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2021,6,29]],"date-time":"2021-06-29T00:00:00Z","timestamp":1624924800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/CTM\/50025\/2020","IF\/00606\/2014"],"award-info":[{"award-number":["UID\/CTM\/50025\/2020","IF\/00606\/2014"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>The dispersion mechanisms in a clay-based polymer nanocomposite (CPNC) during twin-screw extrusion are studied by in-situ rheo-optical techniques, which relate the CPNC morphology with its viscosity. This methodology avoids the problems associated with post extrusion structural rearrangement. The polydimethylsiloxane (PDMS) matrix, which can be processed at ambient and low temperatures, is used to bypass any issues associated with thermal degradation. Local heating in the first part of the extruder allows testing of the usefulness of low matrix viscosity to enhance polymer intercalation before applying larger stresses for clay dispersion. The comparison of clay particle sizes measured in line with models for the kinetics of particle dispersion indicates that larger screw speeds promote the break-up of clay particles, whereas smaller screw speeds favor the erosion of the clay tactoids. Thus, different levels of clay dispersion are generated, which do not simply relate to a progressively better PDMS intercalation and higher clay exfoliation as screw speed is increased. Reducing the PDMS viscosity in the first mixing zone of the screw facilitates dispersion at lower screw speeds, but a complex interplay between stresses and residence times at larger screw speeds is observed. More importantly, the results underline that the use of larger stresses is inefficient per se in dispersing clay if sufficient time is not given for PDMS to intercalate the clay galleries and thus facilitate tactoid disruption or erosion.<\/jats:p>","DOI":"10.3390\/polym13132128","type":"journal-article","created":{"date-parts":[[2021,6,29]],"date-time":"2021-06-29T04:31:07Z","timestamp":1624941067000},"page":"2128","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["In-Line Rheo-Optical Investigation of the Dispersion of Organoclay in a Polymer Matrix during Twin-Screw Compounding"],"prefix":"10.3390","volume":"13","author":[{"given":"Paulo F.","family":"Teixeira","sequence":"first","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0790-5801","authenticated-orcid":false,"given":"Jos\u00e9 A.","family":"Covas","sequence":"additional","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9936-8088","authenticated-orcid":false,"given":"Lo\u00efc","family":"Hilliou","sequence":"additional","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8000","DOI":"10.1021\/ma9603488","article-title":"Polymer melt intercalation in organically-modified layered silicates: Model predictions and experiments","volume":"30","author":"Vaia","year":"1997","journal-title":"Macromolecules"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1083","DOI":"10.1016\/S0032-3861(00)00380-3","article-title":"Nylon 6 nanocomposites by melt compounding","volume":"42","author":"Cho","year":"2001","journal-title":"Polymer"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0927-796X(00)00012-7","article-title":"Polymer-layered silicate nanocomposites: Preparation, properties and uses of a new class of materials","volume":"28","author":"Alexandre","year":"2000","journal-title":"Mat. Sci. Eng. R"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.mser.2006.06.001","article-title":"Structural and mechanical properties of polymer nanocomposites","volume":"53","author":"Tjong","year":"2006","journal-title":"Mat. Sci. Eng. R"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2912","DOI":"10.3390\/polym6122912","article-title":"The effect of multiple extrusions on the properties of montmorillonite filled polypropylene","volume":"6","author":"Delva","year":"2014","journal-title":"Polymers"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.clay.2019.04.016","article-title":"Structural characterization of organo-monmorillonites prepared from a series of primary alkylamines salts: Mid-IR and near-IR study","volume":"176","author":"Slany","year":"2019","journal-title":"Appl. Clay Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"83","DOI":"10.2174\/2405461501666160625080118","article-title":"Polymer-clay nanocomposites, preparations and current applications: A review","volume":"1","author":"Ali","year":"2016","journal-title":"Curr. Nanomat."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"9513","DOI":"10.1016\/S0032-3861(01)00473-6","article-title":"Effect of melt processing conditions on the extent of exfoliation in organoclay-based nanocomposites","volume":"42","author":"Dennis","year":"2001","journal-title":"Polymer"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4259","DOI":"10.1021\/ma052647f","article-title":"Study of intercalation and exfoliation processes in polymer nanocomposites","volume":"39","author":"Bousmina","year":"2006","journal-title":"Macromolecules"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"9929","DOI":"10.1016\/S0032-3861(01)00552-3","article-title":"Nylon 6 nanocomposites: The effect of matrix molecular weight","volume":"42","author":"Fornes","year":"2001","journal-title":"Polymer"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"482","DOI":"10.3139\/217.3827","article-title":"Influence of processing conditions on the preparation of clay-based nanocomposites by twin-screw extrusion","volume":"34","author":"Vergnes","year":"2019","journal-title":"Int. Polym. Proc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1002\/pen.20458","article-title":"Effects of processing conditions on the formation of polypropylene\/organoclay nanocomposites in a twin screw extruder","volume":"46","author":"Lertwimolnun","year":"2006","journal-title":"Polym. Eng. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"517","DOI":"10.3139\/217.2591","article-title":"Influence of twin screw processing conditions on structure and properties of polypropylene-organoclay nanocomposites","volume":"27","author":"Domenech","year":"2012","journal-title":"Int. Polym. Proc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"641","DOI":"10.1002\/pen.21211","article-title":"Estimation of stresses required for exfoliation of clay particles in polymer nanocomposites","volume":"49","author":"Borse","year":"2009","journal-title":"Polym. Eng. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"354","DOI":"10.1021\/ma9020856","article-title":"In situ follow-up of the intercalation process in a clay\/polymer nanocomposite model system by rheo-XRD analysis","volume":"43","author":"Deyrail","year":"2010","journal-title":"Macromolecules"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2252","DOI":"10.1002\/app.27280","article-title":"Effects of extrusion conditions on the properties of recycled poly(ethylene terephthalate)\/nanoclay nanocomposites prepared by a twin-screw extruder","volume":"108","author":"Giraldi","year":"2008","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1046","DOI":"10.1002\/pen.20098","article-title":"Melt compounding of different grades of polystyrene with organoclay. Part 1: Compounding and characterization","volume":"44","author":"Tanoue","year":"2004","journal-title":"Polym. Eng. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1002\/mame.201100419","article-title":"Optimization of extrusion parameters for preparing PCL-layered silica nanocomposites supported by modeling of twin-screw extrusion","volume":"298","author":"Watzeels","year":"2013","journal-title":"Macromol. Mater. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1002\/ceat.201300303","article-title":"Processing conditions effects on dispersion evolution in a twin-screw extruder: Polypropylene-clay nanocomposites","volume":"37","author":"Barbas","year":"2014","journal-title":"Chem. Eng. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"109190","DOI":"10.1016\/j.polymdegradstab.2020.109190","article-title":"In-process assessment of clay dispersion in PLA during melt compounding: Effects of screw speed and filler content","volume":"177","author":"Teixeira","year":"2020","journal-title":"Polym. Degrad. Stabil."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1002\/app.20407","article-title":"Twin screw extrusion compounding of propylene\/organoclay nanocomposites modified by maleated polypropylenes","volume":"93","author":"Wang","year":"2004","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1891","DOI":"10.1002\/app.20658","article-title":"Effects of process conditions and mixing protocols on structure of extruded polypropylene nanocomposites","volume":"93","author":"Zhu","year":"2004","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1007\/s00397-007-0243-2","article-title":"Processing and characterization of biodegradable polymer nanocomposites: Detection of dispersion state","volume":"47","author":"Pogodina","year":"2008","journal-title":"Rheol. Acta"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2395","DOI":"10.1016\/S0032-3861(00)00652-2","article-title":"Polydimethylsiloxane thermal degradation part 1. Kinetics aspects","volume":"42","author":"Camino","year":"2001","journal-title":"Polymer"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1049","DOI":"10.1007\/s00397-009-0387-3","article-title":"Rheological properties of PDMS\/clay nanocomposites and their sensitivity to microstructure","volume":"48","author":"Zhu","year":"2009","journal-title":"Rheol. Acta"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1728","DOI":"10.1021\/cm960127g","article-title":"Structure and dynamics of polymer-layered silicate nanocomposites","volume":"8","author":"Krishnamoorti","year":"1996","journal-title":"Chem. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/S1359-0294(01)00117-0","article-title":"Large-scale structures in sheared colloidal suspensions","volume":"6","author":"Vermant","year":"2001","journal-title":"Curr. Opin. Colloid Interface Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1597","DOI":"10.1021\/cm00057a001","article-title":"Synthesis and properties of new poly(dimethylsiloxane) nanocomposites","volume":"7","author":"Burnside","year":"1995","journal-title":"Chem. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"276","DOI":"10.3144\/expresspolymlett.2019.23","article-title":"Multi-parameter in-process monitoring of clay dispersion during melt compounding with PLA","volume":"13","author":"Teixeira","year":"2019","journal-title":"Express Polym. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.polymertesting.2018.01.013","article-title":"A new double-slit rheometrical die for in-process characterization and extrusion of thermo-mechanically sensitive polymer systems","volume":"66","author":"Teixeira","year":"2018","journal-title":"Polym. Test."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1122\/1.2516399","article-title":"Quantifying dispersion of layered nanocomposite via melt rheology","volume":"51","author":"Vermant","year":"2007","journal-title":"J. Rheol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1007\/BF00396562","article-title":"On the viscosity-temperature behavior of polymer melts","volume":"34","author":"Wang","year":"1995","journal-title":"Rheol. Acta"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1016\/0095-8522(65)90022-X","article-title":"Rheology of non-Newtonian fluids: A new flow equation for pseudoplastic systems","volume":"20","author":"Cross","year":"1965","journal-title":"J. Colloid Sci."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Costa, S., Teixeira, P.F., Covas, J.A., and Hilliou, L. (2019). Assessment of piezoelectric sensors for the acquisition of steady melt pressures in polymer extrusion. Fluids, 4.","DOI":"10.3390\/fluids4020066"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1622","DOI":"10.1021\/ma2012738","article-title":"Shear-induced orientation in well-exfoliated polystyrene\/clay nanocomposites","volume":"45","author":"Dykes","year":"2012","journal-title":"Macromolecules"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1063\/1.1722830","article-title":"Scattering by an inhomogeneous solid II. The correlation function and its application","volume":"28","author":"Debye","year":"1957","journal-title":"J. Appl. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Kerker, M. (1969). The Scattering of Light and Other Electromagnetic Radiation, Academic Press.","DOI":"10.1016\/B978-0-12-404550-7.50008-7"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5538","DOI":"10.1016\/j.polymer.2005.11.098","article-title":"Time dependent light attenuation measurements used in studies of the kinetics of polymer crystallization","volume":"47","author":"Heck","year":"2006","journal-title":"Polymer"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"10908","DOI":"10.1016\/j.polymer.2005.08.091","article-title":"Measuring the extent of exfoliation in polymer\/clay nanocomposites using real-time process monitoring methods","volume":"46","author":"Bur","year":"2005","journal-title":"Polymer"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Kohlbruger, K. (2007). Co-Rotating Twin Screw Extruders, Carl Hanser Verlag.","DOI":"10.3139\/9783446433410.fm"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.polymertesting.2014.05.001","article-title":"In-line particle size assessment of polymer suspensions during processing","volume":"37","author":"Teixeira","year":"2014","journal-title":"Polym. Test."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1002\/andp.19063240204","article-title":"Eine neue Bestimmung der Molek\u00fcldimension","volume":"19","author":"Einstein","year":"1906","journal-title":"Ann. Phys. Leipz."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1002\/andp.19113390313","article-title":"Berichtigung zu meiner Arbeit: Eine neue Bestimmung der Molek\u00fcldimension","volume":"34","author":"Einstein","year":"1911","journal-title":"Ann. Phys. Leipz."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6564","DOI":"10.1016\/j.ces.2005.05.059","article-title":"Analysis of the kinetics of agglomerate erosion in simple shear flows","volume":"60","author":"Scurati","year":"2005","journal-title":"Chem. Eng. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"188","DOI":"10.3139\/217.2319","article-title":"Dynamics of filler size and spatial distribution in a plasticating single screw extruder-modelling and experimental observations","volume":"25","author":"Domingues","year":"2010","journal-title":"Int. Polym. Process."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"MacNally, T., and P\u00f6tschke, P. (2011). Polymer-Carbon Nanotube Composites\u2014Preparation, Properties and Applications, Woodhead Publishing.","DOI":"10.1016\/B978-1-84569-761-7.50029-0"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1803","DOI":"10.1016\/S0009-2509(98)00010-4","article-title":"Dispersion of solids in nonhomogeneous viscous fluids","volume":"53","author":"Hansen","year":"1998","journal-title":"Chem. Eng. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"558","DOI":"10.1002\/pen.760310804","article-title":"Characterization of agglomerate dispersion by erosion in shear flows","volume":"31","author":"Rwei","year":"1991","journal-title":"Polym. Eng. Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2121","DOI":"10.1002\/app.37769","article-title":"New insights in dispersion mechanisms of carbon black in a polymer matrix under shear by rheo-optics","volume":"127","author":"Collin","year":"2013","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Ferr\u00e1s, L.L., Fernandes, C., Semyonov, D., N\u00f3brega, J.M., and Covas, J.A. (2021). Dispersion of grafite nanoplates in polypropylene by melt mixing: The effects of hydrodynamic stresses and residence time. Polymers, 13.","DOI":"10.3390\/polym13010102"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/S0032-5910(97)03235-X","article-title":"Influence of matrix infiltration on the dispersion kinetics of carbon black agglomerates","volume":"92","author":"Yamada","year":"1997","journal-title":"Powder Technol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1963","DOI":"10.1016\/S0009-2509(98)00043-8","article-title":"Observation and analysis of the infiltration of polymer liquids into carbon black agglomerates","volume":"53","author":"Yamada","year":"1998","journal-title":"Chem. Eng. Sci."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/13\/2128\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:26:20Z","timestamp":1760163980000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/13\/2128"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,6,29]]},"references-count":52,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2021,7]]}},"alternative-id":["polym13132128"],"URL":"https:\/\/doi.org\/10.3390\/polym13132128","relation":{},"ISSN":["2073-4360"],"issn-type":[{"type":"electronic","value":"2073-4360"}],"subject":[],"published":{"date-parts":[[2021,6,29]]}}}