magazinelogo

OAJRC Material Science

ISSN Online: 2632-2072 CODEN: OMSAAO
Frequency: Instant publication Email: oajrcms@hillpublish.com
Total View: 403087 Downloads: 26101 Citations: 3 (From Dimensions)

Volumes & Issues

Current Issue

All Volumes

ArticleOpen Access http://dx.doi.org/10.26855/oajrcms.2026.06.003

Comparative Stabilisation Efficacy of Thioester Antioxidant Formulations in Polypropylene (PP) During Multi-pass Extrusion

Brian Johnson1, Norman Sidney Allen2,*, Michele Edge2, Sajid Hussain2, Eldar Zeynalov3

1Chemtura Belgium, Toekomstlaan 13, Herentals 2200, Belgium.

2School of Natural Sciences, Manchester Metropolitan University, Manchester M15GD, UK. 

3Institute of Chemistry, Ministry of Science and Education, Baku, AZ 1143, Azerbaijan.

*Corresponding author: Norman Sidney Allen

Published: May 28, 2026

Abstract

The efficacy of a wide range of mono, di- and phenyl-sulphur substituted antioxidants, and their blends, is assessed and compared with phenol/phosphite antioxidants in the processing of polypropylene as an alternative to phenolic-based stabilisers. Melt flow rate (MFR) measurements via multi-pass single screw (Brabender) extrusion were undertaken, coupled with Yellowness Index for colour inhibition. The outcomes provide novel information in the design of thioesters in relation to their structural activity for effective processing. In this work, mono-substituted thioesters gave some degree of stabilisation, with the effect being dependent upon the alkyl chain length. On the other hand, Di and Phenyl-S-substituted thioesters gave improved MFR protection, either equivalent or better than phenolic or phosphite antioxidants, with a marked dependency on concentration. Mixed thioesters exhibited no synergism, while colour reduction was more effective than that exhibited by phenolic antioxidants. Overall, molar activity and percentage sulphur (active function) appeared to play an important role in melt processability, providing valuable and novel information on their structure-melt processing interrelationship.

Keyword

Thioesters; antioxidants; polypropylene; stabilisation; oxidation

References

[1] Allen NS, Colin X. Properties, chemistry, and mode of action of antioxidants in thermoplastics and rubbers: Recent developments. J Vinyl Addit Technol 2022;28:251-3.

[2] Scott G, editor. Atmospheric Oxidation and Antioxidants. 1st ed. Vol. III. Amsterdam: Elsevier; 1993. 376 p.

[3] Allen NS. Historical Perspectives and Reflections on the Degradation and Stabilisation of Polymer Materials. J Vinyl Addit Technol 2026;:1-31. https://doi.org/10.1002/vnl.70042

[4] Pritchard G, editor. Plastics Additives. London: Chapman and Hall; 1998.

[5] Denisov ET, Denisova TG. Handbook of Antioxidants. Boca Raton: CRC Press; 2000.

[6] Allen NS, editor. Degradation and Stabilisation of Polyolefins. London: Applied Science Publishers; 1983.

[7] Allen NS, Edge M. Perspectives on Additives for Polymers: Aspects of Stabilisation. J Vinyl Addit Technol 2021;1:5-27.

https://doi.org/10.1002/vnl.21807

[8] Allen NS, Edge M, Hussian S. Perspectives on Yellowing in the Degradation of Polymer Materials: Inter-relationship of Structure, Mechanisms and Modes of Stabilisation. Polym Degrad Stab 2022;201:109977.
https://doi.org/10.1016/j.polymdegradstab.2021.109977

[9] Gijsman P, Fiorio R. Long term thermo-oxidative degradation and stabilization of polypropylene (PP) and the implications for its recycla-bility. Polym Degrad Stab 2023;208:110260.
https://doi.org/10.1016/j.polymdegradstab.2023.110260

[10] Pfaender R. A brief History of Plastic Additives: Part 1: Antioxidants. Macromol Mater Eng 2025;310(8):2500039.

https://doi.org/10.1002/mame.202500039

[11] Fay RJ, King RE, Spalding MA, Chatterjee AM, editors. Degradation and Stabilization of Polyethylene. Hoboken: Wiley; 2017.

[12] Chanda M, Roy SK. Plastics Fundamentals, Properties and Testing. Boca Raton: CRC Press; 2009.

[13] Günther A, König T, Habicher WD, Schwetlick K. Antioxidant action of organic sulphites—I. Esters of sulphurous acid as secondary antioxidants. Polym Degrad Stab 1997;55(2):209-16.
https://doi.org/10.1016/S0141-3910(96)00150-4

[14] Hawkins WL. Polymer stabilisation. New York: Wiley and Sons; 1979.

[15] Shelton JR, Harrington ER. Role of certain organic sulfur compounds as preventive antioxidants - 2. Activity of peroxide decomposers and effect of bases. Rubber Chem Technol 1976;49(1):147-57. https://doi.org/10.5254/1.3534943

[16] Carlsson DJ, Brousseau R, Wiles DM. Reactions of sulfur dioxide with oxidised polyolefins. Polym Degrad Stab 1986;15(1):67-79.

https://doi.org/10.1016/0141-3910(86)90005-4

[17] Banach M, Kalinowska B, Konieczny L, Roterman I. Role of Disulfide Bonds in Stabilizing the Conformation of Selected Enzymes—An Approach Based on Divergence Entropy Applied to the Structure of Hydrophobic Core in Proteins. Entropy 2016;18(3):67.

|https://doi.org/10.3390/e18030067

[18] Rogulska M. The Influence of Diisocyanate Structure on Thermal Stability of Thermoplastic Polyurethane Elastomers Based on Diphenylmethane-Derivative Chain Extender with Sulfur Atoms. Materials 2023;16(7):2618.
https://doi.org/10.3390/ma16072618

[19] Ramos F, Camarillo EA, Flores H, Rodriguez-Santiago J. Diphenyl sulfide and 2-aminophenyl phenyl sulfide: An experimental thermo-chemical study. J Chem Thermodyn 2022;172:106832.
https://doi.org/10.1016/j.jct.2022.106832

Copyright

© 2026 by the author(s).
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND) license, which permits non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited and is not modified or adapted.
https://creativecommons.org/licenses/by-nc-nd/4.0/

How to cite this paper

Comparative Stabilisation Efficacy of Thioester Antioxidant Formulations in Polypropylene (PP) During Multi-pass Extrusion

How to cite this paper: Brian Johnson, Norman Sidney Allen, Michele Edge, Sajid Hussain, Eldar Zeynalov. (2026) Comparative Stabilisation Efficacy of Thioester Antioxidant Formulations in Polypropylene (PP) During Multi-pass ExtrusionOAJRC Material Science8(1), 21-36.

DOI: http://dx.doi.org/10.26855/oajrcms.2026.06.003