The temporal variation of some physical and mechanical properties of different polycarbonate greenhouse covering materials and the detection of aging using thermal imaging

Korkmaz C., Tezcan N. Y.

INFRARED PHYSICS AND TECHNOLOGY, vol.150, no.105979, pp.1-13, 2025 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 150 Issue: 105979
  • Publication Date: 2025
  • Doi Number: 10.1016/j.infrared.2025.105979
  • Journal Name: INFRARED PHYSICS AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chimica, Communication Abstracts, Compendex, INSPEC
  • Page Numbers: pp.1-13
  • Akdeniz University Affiliated: Yes

Abstract

This study investigates the changes in mechanical properties (yellowing index and impact resistance) of different polycarbonate (PC) greenhouse covering materials under natural aging conditions over 21 months. Materials studied include UV additive PC (UV PC), UV and infrared additive PC (UV + IR PC), and Polyethylene (PE) with CO-EX technology. A sloped roof structure with a 26.5◦ angle was used, and measurements were taken every three months using a thermal camera to monitor aging, crystalline region changes, and reflectivity. The initial yellowing index values were − 1.46 for UV PC, 4.41 for UV + IR PC and − 1.28 for PE. At completion of study, yellowing index values were 18.4, 14.5 and 18.7, respectively. Initial impact resistance was 1203.4 g for UV PC and 1162.5 g for UV + IR PC. After 21 months, UV PC showed a 20.3 % decrease in impact resistance, while UV + IR PC showed a 6.3 % increase. The results suggest that PE underwent aging, whereas UV PC and UV + IR PC did not show significant aging. Thermal images revealed an inverse relationship between crystalline regions and reflectivity. Overall, UV + IR PC exhibited the best performance, which is especially important for greenhouse cultivation in regions like Antalya. The UV PC material completed 40.6 % of its expected service life.