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Licensed Unlicensed Requires Authentication Published by De Gruyter March 28, 2022

Effect of post-heat treatment on fire retardant treated wood properties

  • Osman Emre Özkan ORCID logo EMAIL logo , Ali Temiz , Önder Tor and Hasan Vurdu
From the journal Holzforschung


In this study, Anatolian black pine (Pinus nigra subsp. pallasiana) was treated with fire retardants of 10, 20, and 30% aqueous solutions composed of di-ammonium phosphate (DAP), borax, boric acid, and glucose to determine the effectiveness of these chemicals in preventing the spread of fire. The treated wood was subjected to post-heat treatment at 120, 150, and 180 °C for 1 h to examine the effects of the post-heat treatment on pH changes, anti-swelling efficiency, water absorption, mechanical strength, accelerated weathering, leaching resistance, thermogravimetric analysis (TGA), UL-94 vertical burning test and crystallinity index. The post-heat treatment of fire-retardant treated wood reduced water intake and increased dimensional stability, while also improving mechanical and thermal properties in general. DAP/glucose complexes promote phosphorus fixation in wood and reduce leaching, resulting in long-term fire protection of wood in service. Because of these improvements in the post-heat treated wood by impregnated fire retardant, it can potentially be used as a reliable engineering material in a wide range of structural applications.

Corresponding author: Osman Emre Özkan, Forest Industry Engineering, Faculty of Forestry, Kastamonu University, Kastamonu 37150, Turkey, E-mail:

Funding source: TUBITAK

Award Identifier / Grant number: 2211-D

Funding source: Kastamonu University Scientific Projects Research Office

Award Identifier / Grant number: Project Number KUBAP-01/2016-33


The authors would like to thank Prof. Dr. Hüseyin Sivrikaya and Assoc. Prof. Dr. Ahmet Can at Bartın University for letting us use their laboratory to test accelerating weathering. We also thank Mehmet Akça for his advice on the chemical test.

  1. Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: This work was supported by TUBITAK (The Scientific and Technological Research Council of Turkey) 2211-D Ph.D. scholarship program and funded by Kastamonu University Scientific Projects Research Office (Project Number KUBAP-01/2016-33).

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.


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Received: 2021-12-02
Accepted: 2022-02-22
Published Online: 2022-03-28
Published in Print: 2022-07-26

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