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Flexibilisation of room-temperature-curing polyaspartic systems
A new study demonstrates that polyaspartic one-coat systems can be significantly flexibilised through targeted polyol modification – without compromising gloss or curing speed. These findings provide a solid basis for further development of room-temperature-curing corrosion protection coatings.
Coatings based on aspartic esters offer numerous advantages: they enable short processing times through a chemical curing reaction at room temperature and provide high resistance to chemical and mechanical stress. However, in comparison to conventional oven-cured polyurethane systems, aspartic coatings show weaknesses – particularly reduced flexibility under thermal or long-term stress.
As part of a scientific study, the potential to improve the flexibility of a one-coat aspartic system by adding hydroxyl-functional binders was investigated. In addition to standard coatings-related tests such as mandrel bend resistance, pot life and drying time, dynamic mechanical thermal analysis (DMTA) was conducted. These tests were complemented by time-resolved IR spectroscopy to analyse the reaction kinetics between polyols and aspartic esters.
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Statistical model supports formulation development
A statistical experimental design focusing on the target values of gloss, flexibility and reaction speed enabled the development of an optimised formulation. The results show that flexibility can be significantly increased through the appropriate selection and dosing of polyol components. At the same time, undesirable effects such as accelerated reaction could be addressed through formulation adjustments.
Improvements were also seen in terms of ageing stability, providing a foundation for further optimisation. This study makes a practice-relevant contribution to the development of high-performance, one-coat aspartic systems for corrosion protection at room temperature.
Source: Lukas Holz, Esslingen University of Applied Sciences, submitted on 29 January 2025
Supervisor: Prof. Dr. Markus Schackmann
Restriction: Restricted until 31 January 2030
