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Material-Preserving Extrusion of Polyamide on a Twin-Screw Extruder. Polymers (Basel) 2023; 15:polym15041033. [PMID: 36850316 PMCID: PMC9962495 DOI: 10.3390/polym15041033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/09/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
In the context of plastics recycling, plastics are processed several times. With each new melting and extrusion the plastic is damaged, which can have a negative effect on product properties. To counteract material damage, special additives such as chain extenders can be used, which are intended to lead to post-polymerization during processing. A linear chain extension is important here, as branching and crosslinking can lead to uncontrolled changes in the plastic's properties. To investigate the suitability of specialized linear chain extenders for polyamides, a polyamide-6 was processed several times and the molar mass distribution was evaluated after each extrusion cycle. Three series of tests were carried out. First, the plastic was regranulated five times without additives and twice with different concentrations of chain extenders on a twin-screw extruder. The results of the study show that not only can molar mass degradation be prevented with the appropriate additive, it is even possible to achieve a material buildup during processing. In our experiments, the polydispersity of the molar mass distribution remained nearly identical despite multiple extrusions. Thus, reactive extrusion makes it possible for the corresponding plastics to be processed several times without the molar mass decreasing. If a sufficiently pure material flow can be ensured during recycling, the number of possible reprocessings of the plastic can be significantly increased without the need to add virgin material.
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Veigel D, Rishi K, Okoli U, Beaucage G, Galloway JA, Campanelli H, Ilavsky J, Kuzmenko I, Fickenscher M. Comparison of nanocomposite dispersion and distribution for several melt mixers. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Rheological Properties and Melt Spinning Application of Controlled-Rheology Polypropylenes via Pilot-Scale Reactive Extrusion. Polymers (Basel) 2022; 14:polym14153226. [PMID: 35956739 PMCID: PMC9371021 DOI: 10.3390/polym14153226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/01/2022] [Accepted: 08/04/2022] [Indexed: 11/25/2022] Open
Abstract
Based on pilot-scale twin-screw reactive extrusion, the structural and rheological properties of controlled-rheology polypropylenes (CR-PPs) are investigated, where the effects of peroxide content and extrusion conditions such as screw configuration, extrusion temperature, and screw speed are prioritized. The active chain cleavage reaction by a small peroxide content of less than 600 ppm inside the extruder gradually increases the melt index and narrows the molecular weight distribution of CR-PPs, thereby affording favorable properties that are applicable to the fiber spinning process. The mechanical properties of CR-PPs are slightly degraded owing to the generation of unsaturated chain ends during the reactive extrusion, which suppresses crystal growth. Under all extrusion conditions, the chain scission and thermal degradation of polypropylene samples occur actively in the harsh twin-screw extruder compared with those in the mild twin-screw extruder. Finally, it is confirmed that CR-PPs can be suitably applied to the melt-spinning process for staple fiber production, thereby guaranteeing a more stable spinning process window against draw resonance instability.
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Canevarolo SV, Mélo TJA, Covas JA, Carneiro OS. Direct Method for Deconvoluting Two Residence Time Distribution Curves. INT POLYM PROC 2022. [DOI: 10.1515/ipp-2001-0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A pair of related Residence Time Distribution (RTD) curves obtained experimentally during extrusion, are deconvoluted using a methodology based on the concept of equivalent residence times. Two points of two RTD curves are equivalent when the same percentage of tracer has exited the system. The time scale of the deconvoluted curve is obtained by subtracting the two equivalent time values of the available RTD curves. The method was tested using simulated pulse-shaped RTD curves and also carrying out measurements on a twin screw extruder. Despite the experimental errors involved, the two tests seem to demonstrate the usefulness of the approach.
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Affiliation(s)
- S. V. Canevarolo
- Universidade Federal de São Carlos, Departamento de Engenharia de Materiais , São Carlos , Brazil
| | | | - J. A. Covas
- Department of Polymer Engineering, University of Minho , Guimarães , Portugal
| | - O. S. Carneiro
- Department of Polymer Engineering, University of Minho , Guimarães , Portugal
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Zhang X, Tzoganakis C, Zatloukal M. Chemical modification of poly(1‐butene) resins through reactive processing. POLYM ENG SCI 2020. [DOI: 10.1002/pen.25391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xiaorong Zhang
- Institute for Polymer Research, Department of Chemical EngineeringUniversity of Waterloo Waterloo Ontario Canada
| | - Costas Tzoganakis
- Institute for Polymer Research, Department of Chemical EngineeringUniversity of Waterloo Waterloo Ontario Canada
| | - Martin Zatloukal
- Faculty of Technology Polymer Centre, Tomas Bata University, Zlin Czech Republic
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Nie S, Tzoganakis C. Tailor‐made controlled rheology polypropylenes from metallocene and Ziegler–Natta resins. POLYM ENG SCI 2019. [DOI: 10.1002/pen.25089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shouliang Nie
- Institute for Polymer Research, Department of Chemical EngineeringUniversity of Waterloo Waterloo Ontario Canada N2L 3G1
| | - Costas Tzoganakis
- Institute for Polymer Research, Department of Chemical EngineeringUniversity of Waterloo Waterloo Ontario Canada N2L 3G1
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Fang H, Mighri F, Ajji A, Cassagnau P, Elkoun S. Flow behavior in a corotating twin-screw extruder of pure polymers and blends: Characterization by fluorescence monitoring technique. J Appl Polym Sci 2010. [DOI: 10.1002/app.33414] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Arzondo L, Pérez C, Carella J. Injection molding of long sisal fiber-reinforced polypropylene: Effects of compatibilizer concentration and viscosity on fiber adhesion and thermal degradation. POLYM ENG SCI 2005. [DOI: 10.1002/pen.20299] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kim B, White JL. Simulation of thermal degradation, peroxide induced degradation, and maleation of polypropylene in a modular co-rotating twin screw extruder. POLYM ENG SCI 2004. [DOI: 10.1002/pen.11701] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Poulesquen A, Vergnes B, Cassagnau P, Michel A, Carneiro OS, Covas JA. A study of residence time distribution in co-rotating twin-screw extruders. Part II: Experimental validation. POLYM ENG SCI 2004. [DOI: 10.1002/pen.10157] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Cha J, White JL. Maleic anhydride modification of polyolefin in an internal mixer and a twin-screw extruder: Experiment and kinetic model. POLYM ENG SCI 2004. [DOI: 10.1002/pen.10824] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mélo TJAD, Canevarolo Jr SV. Determinação da Distribuição de Tempos de Residência em Tempo Real no Processamento Reativo de Blendas Poliméricas. POLIMEROS 2002. [DOI: 10.1590/s0104-14282002000400008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Determinou-se por transmissão de luz a distribuição de tempos de residência (DTR) em tempo real em uma extrusora com rosca dupla co-rotativa e autolimpante onde o sinal do detetor é sensível à presença da segunda fase dispersa, usada como traçador. Vários traçadores foram utilizados em diferentes concentrações: dois pigmentos (TiO2 e ftalocianina) e dois polímeros (poliestireno PS e poliamida-6 PA6) sendo adicionados na forma de um pulso em um fluxo de polipropileno (PP). Os parâmetros temporais (tempos de residência inicial, t i e médio t n e a variância normalizada <FONT FACE=Symbol>s q</FONT>²) medidos nas mesmas condições de processamento são muito próximos, dentro do erro experimental, indicando que a dispersão axial neste tipo de extrusora é independente do traçador. Por outro lado curvas de DTR medidas usando-se um polímero traçador (PS) disperso em um polímero de fluxo (PP) ficam deslocadas no tempo quando a situação é invertida, ou seja, usando-se PP como traçador em um fluxo de PS. Os parâmetros temporais são dependentes das características reológicas do polímero de fluxo, assim diferentes tipos de um mesmo polímero apresentam DTR com formas diferentes e deslocadas no tempo. A intensidade do sinal produzido pelo detetor é dependente não só da concentração mas também das características ópticas do par polímero/traçador, ou polímero/fase dispersa. Misturas poliméricas reativas (PP/PA6/PP-g-AA) e não reativas (PP/PA6) apresentaram diferenças na intensidade do sinal da DTR, devido à ocorrência da reação de graftização com conseqüente mudança na morfologia e no comportamento reológico. Estes resultados foram corroborados com medidas "off-line" por espectroscopia no infravermelho.
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Gugumus F. Physico-chemical aspects of polyethylene processing in an open mixer6. Discussion of hydroperoxide formation and decomposition. Polym Degrad Stab 2000. [DOI: 10.1016/s0141-3910(00)00018-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Santos DM, Canevarolo Jr SV. Sistema portátil para medida on-line da distribuição de tempo de residência na extrusão. POLIMEROS 1999. [DOI: 10.1590/s0104-14281999000200014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A Curva de Distribuição de Tempos de Residência - CDTR tem sido largamente usada para caracterização do tipo de fluxo em extrusoras, sendo que medidas "on-line" permitem diagnosticar de modo muito rápido problemas como desgaste entre a rosca e o barril da extrusora, estagnação do material e outros. A CDTR pode ser determinada fazendo-se uso da técnica de estímulo de pulso único, onde um traçador é introduzido no sistema em um dado instante e sua concentração é estimada na saída. Este artigo propõe um sistema portátil de medida "on-line" feito através da variação da luz transmitida medida com um detector constituído por uma fonte de radiação visível e uma célula fotoelétrica e um software de coleta e tratamento de dados. Usando-se este sistema em uma extrusora de dupla rosca co-rotacional interpenetrante, pode-se verificar que a CDTR é muito mais sensível à variações na taxa de alimentação do que da velocidade de rotação da rosca e que as frações mais lentas do traçador podem demorar quatro vezes mais que as mais rápidas para saírem. Aumento na velocidade de rotação da rosca e/ou redução na taxa de alimentação aumenta o fluxo axial alargando a CDTR.
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Dickson SB, Tzoganakis C, Budman H. Reactive Extrusion of Polypropylene with Pulsed Peroxide Addition: Process and Control Aspects. Ind Eng Chem Res 1997. [DOI: 10.1021/ie960288u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven B. Dickson
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Costas Tzoganakis
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Hector Budman
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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Cheung PC, Balke ST. Reactive Extrusion of Polypropylene/Polyethylene Blends: Kinetic Model Development. Ind Eng Chem Res 1997. [DOI: 10.1021/ie960480w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. C. Cheung
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3E5
| | - S. T. Balke
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3E5
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Tzoganakis C. A rheological evaluation of linear and branched controlled-rheology polypropylenes. CAN J CHEM ENG 1994. [DOI: 10.1002/cjce.5450720425] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pabedinskas A, Cluett WR, Balke ST. Modeling of polypropylene degradation during reactive extrusion with implications for process control. POLYM ENG SCI 1994. [DOI: 10.1002/pen.760340708] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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