Hydrolysis and degradation of PET fibers in alkaline cement extraction solution: changes in physical, chemical, and mechanical properties

Research Background and System: Polyethylene terephthalate (PET) fibers are commonly used to enhance cement-based composite materials. However, in the highly alkaline environment of the cementitious matrix pore solution, PET may undergo hydrolysis degradation, which in turn affects the long-term performance of the composite material. A study published in Volume 254 of Polymer Degradation and Stability (December 2026) systematically investigated the alkaline hydrolysis process of PET fibers using a cement-based extraction solution based on LC ³ (limestone calcined clay cement) as the medium. This study was jointly conducted by Ameer Hamza Ahmed, Julia H ü bner, Marco Liebscher, Anna Jose, Ali Bashiri Rezaie, Christina Scheffler, and Viktor Mechtcherine, covering degradation characterization at the physical, chemical, and mechanical levels.

Three levels of degradation characterization

From the scope defined by the research title, the work revolves around physical, chemical, and mechanical degradation.

. At the physical level, attention is paid to the morphological and structural changes of fibers under the action of alkaline media; Chemical focus on the chain breakage and product generation of PET molecular chains in alkaline hydrolysis; At the mechanical level, the impact of hydrolysis on the load-bearing capacity of fibers is evaluated. The combination of the three can help establish a correlation from chemical structural changes to macroscopic mechanical property losses. It should be pointed out that the source text only provides the title, journal issue, and author information, and does not disclose specific experimental conditions, hydrolysis rate, mechanical property retention rate, and other data. Therefore, this article does not make any inferences about the above values. The significance of this work in the field of polymer aging and stabilization lies in placing polymer aging research in a real cement-based alkaline environment. For the polymer additive industry, the durability design of fiber-reinforced cement-based materials is essentially a matter of polymer aging and weather stability. The hydrolysis of PET under alkaline conditions belongs to the chemical degradation pathway, and when combined with common aging factors such as ultraviolet light and thermal oxygen, the assessment of material life becomes more complex. In terms of stabilization schemes, for hydrolytic degradation, the antioxidant system can suppress thermal oxidative aging during processing and service, while HALS (hindered amine light stabilizer) and UVA (ultraviolet absorber) mainly deal with photo oxidative aging; For outdoor scenarios where cement-based composite materials are exposed, the composite system is often better able to accommodate multiple aging pathways than a single additive. This study suggests that alkaline hydrolysis should be considered as an independent aging variable when evaluating the effectiveness of such additives, rather than relying solely on conventional photothermal aging tests. In addition, the study used cement-based extraction solution instead of simple alkali solution as the medium, which is closer to the actual pore solution composition. This provides a reference for the medium selection in polymer aging research. For practitioners engaged in the formulation and stabilization design of fiber-reinforced cement-based materials, such characterization methods can help identify hydrolysis sensitivity issues during the material selection stage.

To be clarified

Due to the lack of specific experimental data and conclusion details disclosed in the source, the degree of hydrolysis and mechanical property degradation of PET fibers in LC ³ extraction solution, as well as the evaluation of whether stabilization agents are involved, all need to be confirmed by consulting the original text.

. Subsequent attention can be paid to whether the study provides degradation kinetics parameters and proposes stabilization suggestions for alkaline environments.

Information source:Alkaline hydrolysis of polyethylene terephthalate fibers in an LC³-based cementitious extract: physical, chemical, and mechanical degradation， Organized by Herun Chemical.