PU Foams Resistance Against Natural Weathering Aging: The Effect of Coffee Husk Residues in Different Contents

Author(s)

Maia, Lana S. S. ; Zanini, Noelle C. C. ; Camani, Paulo H. H. ; Medeiros, Simone F. F. ; Rosa, Derval S. S. ; Mulinari, Daniella R. R.

• Document type: Journal article
• Source: JOURNAL OF POLYMERS AND THE ENVIRONMENT; v. N/A, p. 20-pg., 2022-12-19.

Abstract

Due to high consumption and high demand for polyurethane (PU) foams, they are usually exposed to the environment, suffering the influence and action of weathering. Then, this work investigates the coffee husk residues (CHR) introduction to PU foams obtained from castor oil. A comparative study on the effect of weathering on neat PU foams and CHR-contained PU foams was carried out. After 6 months of aging, an increase in weight for all samples was observed in the first days due to moisture absorption, with a subsequent decline in the weight of the samples until completing 6 months of testing. Comparing neat PU and PU composite foams, high CHR content promoted higher weight loss. Weathering aging changed other properties, such as the decrease in the apparent density of the foams, which was generated by degrading processes of oxidation and photodegradation. Besides, hydrolytic processes arise from UV radiation, temperature variation, and humidity present in the environment to which samples were exposed. Due to this degradation, high crystallinity, mechanical properties, hydrophilicity, and thermal stability were verified. However, the degradative effect of weathering was mitigated due to the addition of coffee husk residues (especially between 5 and 20% CHR). It showed that the coffee husk in the matrix of PU foams resulted in a protective effect on the degradative process, avoiding severe property losses or structural alteration in the PU foams. These characteristics may promote an application of the PU composite foam for civil construction areas, as protective material against weathering. (AU)

• FAPESP's process: 19/16301-6 - Starch aerogels containing modified nanocellullose for removal of heavy metals in wastewater from the industry sector
• Grantee: Paulo Henrique Camani
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 20/13703-3 - Environmentally friendly porous materials for the recovery and revaluation of metals reclaimed from contaminated water
• Grantee: Derval dos Santos Rosa
• Support Opportunities: Research Projects - Thematic Grants