Thermal, Thermomechanical, and Fire Behaviour of Casein-Modified Unsaturated Polyester Resin Biocomposites
- 1Department of Polymer Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, Gliniana 33, 20-614 Lublin, Poland
- 2Department of Technology and Polymer Processing, Faculty of Mechanical Engineering, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin, Poland
Abstract
The increasing demand for sustainable engineering thermosets, such as unsaturated polyester resins (UPR), together with stricter fire safety requirements, promotes the development of environmentally friendly polymer composites. In this study, UPR synthesized from recycled post-consumer poly(ethylene terephthalate) was modified with casein particles to investigate their effects on thermal, thermomechanical, and fire-related properties. The obtained biocomposites were characterized by thermal analysis, thermomechanical testing, and flammability evaluation. Casein incorporation affected the degradation behaviour of UPR and promoted residue formation at elevated temperatures. Cone calorimetry demonstrated a reduction in peak heat release rate from 600 to 407 kW·m−2 and total heat release from 86 to 65 MJ·m−2 for the composite containing 15 wt.% casein. The maximum average rate of heat emission decreased from 345 to 255 kW·m−2, while combustion residue increased from 0.1 to 3.5%, confirming enhanced char formation. Fire performance also improved, with the Fire Potential Index increasing from 0.053 to 0.071 m2·s·kW−1 and the Fire Retardancy Index reaching 1.77 for UPR+C15. The heat deflection temperature increased from 56.9 to 71.3 °C, whereas the Vicat softening temperature decreased slightly. Overall, casein is a promising bio-based additive for tailoring the properties of sustainable UPR composites.
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BibTeX
@article{paczkowski2026thermal,
title = {{Thermal, Thermomechanical, and Fire Behaviour of Casein-Modified Unsaturated Polyester Resin Biocomposites}},
author = {Przemysław Pączkowski and Karolina Głogowska and Bronisław Samujło and Barbara Gawdzik},
journal = {Polymers},
year = {2026},
month = oct,
doi = {10.3390/polym18202552},
url = {https://www.mdpi.com/2073-4360/18/20/2552},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Thermal, Thermomechanical, and Fire Behaviour of Casein-Modified Unsaturated Polyester Resin Biocomposites
AU - Przemysław Pączkowski
AU - Karolina Głogowska
AU - Bronisław Samujło
AU - Barbara Gawdzik
PY - 2026
DA - 2026/10/01
JO - Polymers
DO - 10.3390/polym18202552
UR - https://www.mdpi.com/2073-4360/18/20/2552
AB - The increasing demand for sustainable engineering thermosets, such as unsaturated polyester resins (UPR), together with stricter fire safety requirements, promotes the development of environmentally friendly polymer composites. In this study, UPR synthesized from recycled post-consumer poly(ethylene terephthalate) was modified with casein particles to investigate their effects on thermal, thermomechanical, and fire-related properties. The obtained biocomposites were characterized by thermal analysis, thermomechanical testing, and flammability evaluation. Casein incorporation affected the degradation behaviour of UPR and promoted residue formation at elevated temperatures. Cone calorimetry demonstrated a reduction in peak heat release rate from 600 to 407 kW·m−2 and total heat release from 86 to 65 MJ·m−2 for the composite containing 15 wt.% casein. The maximum average rate of heat emission decreased from 345 to 255 kW·m−2, while combustion residue increased from 0.1 to 3.5%, confirming enhanced char formation. Fire performance also improved, with the Fire Potential Index increasing from 0.053 to 0.071 m2·s·kW−1 and the Fire Retardancy Index reaching 1.77 for UPR+C15. The heat deflection temperature increased from 56.9 to 71.3 °C, whereas the Vicat softening temperature decreased slightly. Overall, casein is a promising bio-based additive for tailoring the properties of sustainable UPR composites.
SN - 2073-4360
ER -