THERMAL AND MECHANICAL-PROPERTIES OF CELLULAR POLYSTYRENE AND POLYURETHANE INSULATION MATERIALS AGED ON A FLAT ROOF IN HOT-DRY CLIMATE


OZKAN E.

JOURNAL OF TESTING AND EVALUATION, cilt.22, ss.149-160, 1994 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 22 Konu: 2
  • Basım Tarihi: 1994
  • Dergi Adı: JOURNAL OF TESTING AND EVALUATION
  • Sayfa Sayıları: ss.149-160

Özet

Cellular polymers, which have been increasingly used for thermal insulation of external walls and roofs since the 1970s, degrade in some cases. The heat transmission of a cellular polymer insulator, the k value, is predominantly dependent on the heat conduction of the air or gas remaining in the cells. An insulator may be aged and start transmitting more energy due to replacement of cell content with different gases or moisture or both, changes in size, softening and creeping under pressure and heat, or penetration of water or mineral particles into cells, or a combination thereof. The solid face also degrades due to ultraviolet light, heat and atmospheric oxygen.