Abstract
Melt post-condensation and thermal and thermo-oxidative degradation of a cycloaliphatic polyamide (Trogamid™ CX7323) were studied through time-resolved rheometry (TRR). The implemented TRR elucidates structural changes occurring during the two concurrent phenomena, namely, melt post-condensation and thermal/thermo-oxidative degradation, during the time sweep in a parallel plate rheometer. TRR measurements were conducted on neat Trogamid™ under nitrogen (inert/non-oxidative) and air (oxidative) environment at 3% strain amplitude and a range of frequencies between 0.1 and 100 rad/s for a duration of 2 h. The linear viscoelastic properties of the transparent polyamide showed an exponential increase with time at 255 ºC under both oxidative and non-oxidative environments, suggesting an increase in molecular mass. At temperatures of 260, 270, and 275 ºC, a dual-stage time-dependent growth in viscoelastic properties was observed under an oxidative environment. Thermo-oxidative degradation of the polymer melts at 270 ºC occurs from the exposed edge of the sample, continuing inwards, effectively reducing the radius of the unoxidized polymer melt by 6.4% from its initial value of 12.5 mm. In the dual-stage growth, the first exponential growth is attributed to post-condensation with continuous desorption of water, followed by logistic oxidative degradation. Furthermore, a new methodology is presented to interpret and differentiate the rheological behavior of the bulk polymer melt from the oxidized segment present within the volume of the test sample.
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Data availability
The datasets generated during and/or analysed during the current study are available in the MaterialsCloud repository (Venoor et al. 2022).
Code availability
MATLAB code to conduct data smoothing and interpolation can be obtained from the corresponding author on reasonable request. Also, a code to analyze linear viscoelastic properties using the torque recordings obtained from the parallel plate rheometer is presented in the supplementary file.
References
Acierno S, Van Puyvelde P (2005) Rheological behavior of polyamide 11 with varying initial moisture content. J Appl Polym Sci 97:666–670. https://doi.org/10.1002/app.21810
American Society for Testing and Materials (2017) ASTM D7191–18, test method for determination of moisture in plastics by relative humidity sensor. ASTM International, West Conshohocken, PA
ASTM Internantional (2019) ASTM D789–19 standard test method for determination of relative viscosity of concentrated polyamide (PA) solutions. ASTM International, West Conshohocken, PA
Bernstein R, Derzon DK, Gillen KT (2005) Nylon 6.6 accelerated aging studies: thermal–oxidative degradation and its interaction with hydrolysis. Polym Degrad Stab 88:480–488. https://doi.org/10.1016/j.polymdegradstab.2004.11.020
Cai L-H, Qi Z-G, Xu J et al (2017) Thermo-oxidative degradation of Nylon 1010 films: colorimetric evaluation and its correlation with material properties. Chin Chem Lett 28:949–954. https://doi.org/10.1016/j.cclet.2016.11.017
Colin X, Fayolle B, Audouin L, Verdu J (2006) The classical kinetic model for radical chain oxidation of hydrocarbon substrates initiated by bimolecular hydroperoxide decomposition. Int J Chem Kinet 38:666–676
Dijkstra DJ (2009) Guidelines for rheological characterization of polyamide melts: (IUPAC technical report). Pure Appl Chem 81:339–349. https://doi.org/10.1351/PAC-REP-08-07-22
Dolden JG (1976) Structure-property relationships in amorphous polyamides. Polymer 17:875–892
Dong W, Gijsman P (2010) Influence of temperature on the thermo-oxidative degradation of polyamide 6 films. Polym Degrad Stab 95:1054–1062. https://doi.org/10.1016/j.polymdegradstab.2010.02.030
El-Mazry C, Ben Hassine M, Correc O, Colin X (2013) Thermal oxidation kinetics of additive free polyamide 6–6. Polym Degrad Stab 98:22–36. https://doi.org/10.1016/j.polymdegradstab.2012.11.002
Evonik (2019) TROGAMID® CX Transparent polyamides with an outstanding combination of properties. Evonik Industries
Evonik (2020) TROGAMID® CX - clearly convincing polyamides. https://www.trogamid.com/product/trogamid/en/products-services/trogamid-cx/. Accessed 20 Sep 2020
Ferry JD (1980) Viscoelastic properties of polymers. John Wiley & Sons
Filippone G, Carroccio SC, Curcuruto G et al (2015a) Time-resolved rheology as a tool to monitor the progress of polymer degradation in the melt state – Part II: thermal and thermo-oxidative degradation of polyamide 11/organo-clay nanocomposites. Polymer 73:102–110. https://doi.org/10.1016/j.polymer.2015.07.042
Filippone G, Carroccio SC, Mendichi R et al (2015b) Time-resolved rheology as a tool to monitor the progress of polymer degradation in the melt state – Part I: thermal and thermo-oxidative degradation of polyamide 11. Polymer 72:134–141. https://doi.org/10.1016/j.polymer.2015.06.059
Gijsman P, Tummers D, Janssen K (1995) Differences and similarities in the thermooxidative degradation of polyamide 46 and 66. Polym Degrad Stab 49:121–125
Grigg MN (2006) Thermo-oxidative degradation of polyamide 6. PhD Thesis, Queensland University of Technology
Habib KMM PlotPub - publication quality graphs in MATLAB. Version 1.5.0.0. MathWorks. URL https://github.com/masumhabib/PlotPub
Hager H, Hasskerl T, Wursche R, et al (2007) High-transparency laser-markable and laser-weldable plastic materials
Hauver C (2011) The effect of additives on Trogamid CX7323’s ballistic performance. University of Massachusetts Lowell
Hsich H-Y, Yanyo LC, Ambrose RJ (1984) A relaxation model for property changes during the cure reaction of filled and unfilled silicone elastomers. J Appl Polym Sci 29:2331–2345
Jackson C, Chen Y-J, Mays JW (1996) Dilute solution properties of randomly branched poly (methyl methacrylate). J Appl Polym Sci 59:179–188
Karstens T, Rossbach V (1989) Thermo-oxidative degradation of polyamide 6 and 6, 6. Kinetics of the formation and inhibition of UV/VIS-active chromophores. Makromol Chem Macromol Chem Phys 190:3033–3053
Khanna YP, Han PK, Day ED (1996) New developments in the melt rheology of nylons. I: effect of moisture and molecular weight. Polym Eng Sci 36:1745–1754. https://doi.org/10.1002/pen.10570
Kruse M, Wagner MH (2016) Time-resolved rheometry of poly(ethylene terephthalate) during thermal and thermo-oxidative degradation. Rheol Acta 55:789–800. https://doi.org/10.1007/s00397-016-0955-2
Kuroda S, Mita I (1989) Degradation of aromatic polymers—II. The crosslinking during thermal and thermo-oxidative degradation of a polyimide. Eur Polym J 25:611–620
Li R, Hu X (1998) Study on discoloration mechanism of polyamide 6 during thermo-oxidative degradation. Polym Degrad Stab 62:523–528. https://doi.org/10.1016/S0141-3910(98)00037-8
Mao B, Cebe P (2013) Avrami analysis of melt crystallization behavior of Trogamid. J Therm Anal Calorim 113:545–550. https://doi.org/10.1007/s10973-013-3272-3
Matisová-Rychlá L, Lanska B, Rychlỳ J (1994) Application of chemiluminescence to polymer degradation studies. Thermal oxidation of polyamide 6. Angew Makromol Chem Appl Macromol Chem Phys 216:169–186
Morrison FA (2001) Understanding rheology. Oxford University Press
Mours M, Winter HH (1994) Time-Resolved Rheometry Rheol Acta 33:385–397
Peterson JD, Vyazovkin S, Wight CA (2001) Kinetics of the thermal and thermo-oxidative degradation of polystyrene, polyethylene and poly (propylene). Macromol Chem Phys 202:775–784
Pham DT, Dotchev KD, Yusoff WAY (2008) Deterioration of polyamide powder properties in the laser sintering process. Proc Inst Mech Eng Part C J Mech Eng Sci 222:2163–2176
Qian Z, McKenna GB (2018) Expanding the application of the van Gurp-Palmen plot: new insights into polymer melt rheology. Polymer 155:208–217. https://doi.org/10.1016/j.polymer.2018.09.036
Salehiyan R, Malwela T, Ray SS (2017) Thermo-oxidative degradation study of melt-processed polyethylene and its blend with polyamide using time-resolved rheometry. Polym Degrad Stab 139:130–137
Song JW, Lofgren JD, Hart K et al (2006) Aromatic nylons for transparent armor applications. Army Natick Soldier Research Development And Engineering Center, Natick, MA
Souza AMC, Lepretre DS, Demarquette NR et al (2010) Influence of water content, time, and temperature on the rheological behavior of polyethylene terephtalate. J Appl Polym Sci 116:3525–3533
Trinkle S, Friedrich C (2001) Van Gurp-Palmen-plot: a way to characterize polydispersity of linear polymers. Rheol Acta 40:322–328. https://doi.org/10.1007/s003970000137
Trinkle S, Walter P, Friedrich C (2002) Van Gurp-Palmen Plot II – classification of long chain branched polymers by their topology. Rheol Acta 41:103–113. https://doi.org/10.1007/s003970200010
Van Gurp M, Palmen J (1998) Time-temperature superposition for polymeric blends. Rheol Bull 67:5–8
Venoor V, Park JH, Kazmer DO, Sobkowicz MJ (2020) Understanding the effect of water in polyamides: a review. Polym Rev 0:1–49. https://doi.org/10.1080/15583724.2020.1855196
Venoor V, Ratto JA, Kazmer D, Sobkowicz M (2022) Predicting the influence of edge oxidation in parallel-plate rheometry. Materials Cloud Archive. https://doi.org/10.24435/materialscloud:cb-xf
Wang Y, Chen S, Guang S et al (2019) Continuous post-polycondensation of high-viscosity poly (ethylene terephthalate) in the molten state. J Appl Polym Sci 136:47484
K Wudy D Drummer F Kühnlein M Drexler (2014) Influence of degradation behavior of polyamide 12 powders in laser sintering process on produced parts. In: AIP Conference Proceedings. American Institute of Physics, pp 691–695
Yoo Y, Paul DR (2008) Effect of organoclay structure on morphology and properties of nanocomposites based on an amorphous polyamide. Polymer 49:3795–3804. https://doi.org/10.1016/j.polymer.2008.06.014
Zhang J, Adams A (2016) Understanding thermal aging of non-stabilized and stabilized polyamide 12 using 1H solid-state NMR. Polym Degrad Stab 134:169–178
Zheng W, Lee YH, Park CB (2006) The effects of exfoliated nano-clay on the extrusion microcellular foaming of amorphous and crystalline nylon. J Cell Plast 42:271–288
Acknowledgements
The authors would like to thank the Department of Plastic Engineering at the University of Massachusetts Lowell and the US Army Combat Capabilities Development Command Soldier Center for the partial funding, experimental facilities, and instruments. The plots for the article were created using a modified version of MATLAB open-source code (Habib). As shown in this article, a sample code to achieve the quality of plots can be provided upon request.
Funding
This research was funded jointly by the US Army Combat Capabilities Development Command Soldier Center (DEVCOM SC) and Harnessing Emerging Research Opportunities to Empower Soldiers (HEROES) Contract #W911QY-17–2-0004, Soldier Lightweight Integrated Multifunctional Materials (SLIMM) project title MN-1 New thermoplastic materials using microcrystalline cellulose, and the UMass President’s Office Technology and Commercial Ventures Fund.
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All authors contributed to the study conception. Material preparation and testing and data analysis were performed by Varun Venoor. The first draft of the manuscript was written by Varun Venoor, and all authors reviewed the previous version. The final version of the manuscript was reviewed and approved by all authors.
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The document has been screened and approved for release by G2 and PAO at the US Army Combat Capabilities Development Command Soldier Center, Natick, MA. The assigned number is PR2021_32660.
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Venoor, V., Ratto, J.A., Kazmer, D.O. et al. Analysis of post-condensation and thermo-oxidative degradation in cycloaliphatic polyamide through time-resolved rheology (TRR). Rheol Acta 61, 319–337 (2022). https://doi.org/10.1007/s00397-022-01327-2
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DOI: https://doi.org/10.1007/s00397-022-01327-2