Materials (Sep 2022)

Recycling of Flexible Polyurethane Foams by Regrinding Scraps into Powder to Replace Polyol for Re-Foaming

  • Lei Guo,
  • Wenchao Wang,
  • Xiurui Guo,
  • Kuanfa Hao,
  • Haichao Liu,
  • Yuan Xu,
  • Gongxu Liu,
  • Shouyun Guo,
  • Lichen Bai,
  • Donghui Ren,
  • Fumin Liu

DOI
https://doi.org/10.3390/ma15176047
Journal volume & issue
Vol. 15, no. 17
p. 6047

Abstract

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In the context of protecting the ecological environment and carbon neutrality, high-value recycling of flexible polyurethane foam (F-PUF) scraps, generated in the production process, is of great significance to save petroleum raw materials and reduce energy consumption. In the present study, F-PUF scraps were ground into powder by strong shear regrinding using two-roll mill and then reused as a partial replacement of polyol for re-foaming. A series of characterizations were employed to investigate the effect of milling cycles, roller temperatures, and content of the powder on the properties of the powder and F-PUF containing powder. It was revealed that the mechanochemical effect induced breaking of the cross-linking structure and increased activity of the powder. The volume mean diameter (VMD) of powder prepared with 7 milling cycles, at room temperature, is about 97.73 μm. The microstructure and density of the F-PUF containing powder prepared in the above-mentioned manner to replace up to 15 wt.% polyol, is similar to the original F-PUF, with resilience 49.08% and compression set 7.8%, which indicates that the recycling method will play an important role in industrial applications.

Keywords