DOI QR코드

DOI QR Code

Changes in the Amount of PEG Free-Flowing Back from PEG-Treated Waterlogged Archaeological Wood and the Compressive Strength According to Relative Humidity Conditions

습도조건에 따른 PEG 처리 수침고목재의 PEG 용출량 및 압축강도 변화

  • Jo, Ah Hyeon (Cultural Heritage Conservation Science Center, National Research Institute of Cultural Heritage) ;
  • Lee, Kwang-Hee (Research Institute of Wooden Cultural Heritage, Korea National University of Cultural Heritage) ;
  • Choi, Tae-Ho (Department of Wood and Paper Science, Chungbuk National University) ;
  • Go, In Hee (Department of Conservation Heritage Science, Chungbuk National University) ;
  • Seo, Jeong-Wook (Department of Wood and Paper Science, Chungbuk National University)
  • 조아현 (국립문화재연구소 문화재보존과학센터) ;
  • 이광희 (한국전통문화대학교 목제문화재연구소) ;
  • 최태호 (충북대학교 목재.종이과학과) ;
  • 고인희 (충북대학교 문화재협동과정) ;
  • 서정욱 (충북대학교 목재.종이과학과)
  • Received : 2020.06.06
  • Accepted : 2020.06.18
  • Published : 2020.06.20

Abstract

The present study aimed to monitor changes in the amount of PEG free-flowing back from PEG-treated woods and compressive strength changes with change in relative humidity from 90% to 30%. The change in the relative humidity was done 3 times. For the current study, water-logged wood (Prinus group) was used and the wooden blocks cut out of it were subjected to 3 different impregnation methods combined with different drying conditions as follows: 1) impregnating with 80% PEG#4000 followed by drying in nature (hereafter PEG80), 2) impregnating with 40% PEG#4000 and then drying in vacuum freeze drying equipment (hereafter PEG40), and 3) impregnating with 40% PEG#4000 in t-butanol, followed by drying in the vacuum freeze drying equipment (hereafter TB40). It was verified that most of the PEG was free-flowing back from the PEG-treated woods; however, a small amount of left PEG was observed on the lumen surface. The amount of PEG free-flowing back from the PEG-treated woods increased whenever the relative humidity changes from 90% to 30%. The compressive strengths of PEG80 and TB40 were increased whenever the relative humidity changed from 90% to 30%, whereas PEG40 decreased. The current study showed how to control the relative humidity to effectively manage PEG-treated waterlogged woods.

본 연구는 PEG 함침처리한 수침고목재를 대상으로 고습도(RH 90%)에서 저습도(RH 30%)로 습도변화를 주면서 목재 내부에 있는 PEG 및 약제 용출량과 압축강도 특성 변화를 관찰하기 위해 수행되었다. 고습도에서 저습도로의 변화는 3회 실시하였다. 시험에 사용된 수침목재는 졸참나무류(Prinus group)이며, 함침 및 건조 방법은 1) PEG 완료농도 80% 및 자연건조(이하 PEG80), 2) PEG 완료농도 40% 및 진공동결건조(이하 PEG40), 그리고 3) t-butanol을 이용한 PEG 완료농도 40% 및 진공동결건조(이하 TB40) 이다. 목재 내부에 있는 PEG는 3차 습도변화 이후에 대부분 용출되어 제거되었으며, 내강 벽면에 남은 PEG의 결정이 편평하게 고착되었다. 약제의 용출량은 대부분의 경우 습도변화 횟수가 증가할수록 그 양이 증가하였다. 습도조건에 따른 압축강도의 변화는 PEG80과 TB40의 경우 습도변화 횟수가 증가할수록 증가하였으나, PEG40은 감소하였다. 본 연구를 통해 PEG 처리된 수침고목재 보존을 위한 습도조건에 대한 계획 마련에 필요한 기초자료가 마련되었다.

Keywords

References

  1. Baird, J.A., Olayo-Valles, R., Rinaldi, C. and Taylor, L.S., 2010, Effect of molecular weight, temperature, and additives on the moisture sorption properties of polyethylene glycol. Journal of Pharmaceutical Sciences, 99(1), 154-168. https://doi.org/10.1002/jps.21808
  2. Giachi, G., Capretti, C., Macchioni, N., Pizzo, B. and Donato, I.D., 2010, A methodological approach in the evaluation of the efficacy of treatments for the dimensional stabilisation of waterlogged archaeological wood. Journal of Cultural Heritage, 11(1), 91-101. https://doi.org/10.1016/j.culher.2009.04.003
  3. Grattan, D.W., 1982, A practical comparative study of several treatments for waterlogged wood. Studies in Conservation, 27(3), 124-136. https://doi.org/10.1179/sic.1982.27.3.124
  4. Grattan, D.W., 1987, 3-Waterlogged wood. Conservation of marine archaeological objects, Butterworth-Heinemann, London, 55-67.
  5. Grattan, D.W. and Clarke, R.W., 1987, 9-Conservation of waterlogged wood. Conservation of marine archaeological objects, Butterworth-Heinemann, London, 164-206.
  6. Hollstein, E., 1965, Jahrringchronologische datierungen von eichenhoelzern ohne waldkante. Bonner Jahrbuecher, 165, 12-27.
  7. Hong, S.H., Kim, C.H., Lim, H.M. and Kang, H.Y., 2013, Measuring PEG retentions and EMCs of PEG impregnated softwood specimens after heat-treatment. Journal of the Korean Wood Science and Technology, 41(3), 173-180. (in Korean with English abstract) https://doi.org/10.5658/WOOD.2013.41.3.173
  8. Jensen. P., Jorgensen. G. and Schnell, U., 2001, Dynamic LV-SEM analysis of freeze drying processes for waterlogged wood. Proceedings of the 8th ICOM Group on Wet Organic Archaeological Materials Conference, Stockholm, 319-333.
  9. Kang, A.K. and Park, S.J., 1996, Micromorphological changes of waterlogged archaeological wood in PEG4000 and sucrose treatment. Conservation and Restoration of Cultural Heritage, 5(2), 3-14. (in Korean with English abstract)
  10. Kaye, B., 1995, Conservation of waterlogged archaeological wood. Chemical Society Reviews, 24(1), 35-43. https://doi.org/10.1039/CS9952400035
  11. Kim, G.S. and Yi, Y.H., 1999, The vacuum freeze-drying experiment for water-logged wood excavated from Wolpyongdong in Taejon. Conservation Science in Museum, 1, 27-35. (in Korean with English abstract) https://doi.org/10.22790/CONSERVATION.1999.1.0027
  12. Kim, S.C., Park, W.K. and Lee, G.H., 2004, Dimensional change of PEG-freeze dried waterlogged woods exposed at various humidity conditions. Journal of Conservation Science, 16, 110-118. (in Korean with English abstract)
  13. Kim, S.C., 2003, PEG Concentration and solvent selection for freeze-drying of waterlogged archaeological woods. Degree of Master, Chungbuk National University, Cheongju. 31-70. (in Korean with English abstract)
  14. Kim, S.C., 2012, Compressive strength of waterlogged archaeological wood after PEG treatment with concentration and solvent. Journal of Conservation Science, 28(2), 95-99. (in Korean with English abstract) https://doi.org/10.12654/JCS.2012.28.2.095
  15. Moon, W.S., 1987, Strength test and adhesive strength test of P.E.G. Treated Wood. Conservation Studies, 8, 149-167. (in Korean)
  16. Murmanis, L., 1975, Formation of tyloses in felled Quercus rubra L.. Wood Science and Technology, 9(1), 3-14. https://doi.org/10.1007/BF00351911
  17. Oh, S.W., 1998, The Relationship between anatomical characteristics and compression strength parallel to grain in major species of Lepidobalanus. Journal of the Korean Wood Science and Technology, 26(1), 63-69. (in Korean with English abstract)
  18. Park, S.J., 1997. Studies on dimensional stabilization of water-logged small archaeological woods. Korea Science and Engineering Foundation, 36. (in Korean with English abstract)
  19. Park, S.J., Lee, W.Y. and Lee, H.H., 2006, Timber organization and identification. Hyangmunsa, Seoul, 209. (in Korean)
  20. Schniewind, A.P. and KronPkright, D.P., 1987, Strength evaluation of deteriorated wood treated with consolidants. Studies in Conservation, 29(1), 146-150. https://doi.org/10.1179/sic.1984.29.Supplement-1.146
  21. Seo, J.H., 2008, Conservation methodology for cultural heritage. Kyunginmunhwasa, Seoul, 81-139. (in Korean)
  22. Tahira, A., Howard, W., Pennington, E.R. and Kennedy, A., 2017, Mechanical strength studies on degraded waterlogged wood treated with sugars. Studies in Conservation, 62(4), 223-228. https://doi.org/10.1080/00393630.2016.1169364
  23. The Samhan Institute of Cultural Properties, 2018, The ruins of Goryeong Jik-ri and Sachon-ri. Academic Research Series, 76, 611-635. (in Korean)
  24. Yi, Y.H., 1997, Conservation of waterlogged wooden finds excavated in wet-site. Journal of Conservation Science, 6(2), 126-140. (in Korean with English abstract)
  25. Yi, Y.H., Kim, S.C., Park, Y.M. and Kim, K.S., 2000, Experiment on conservation treatment method(PEG, sucrose and lactitol) and degree of state-change with RH of waterlogged archaeological wood. Conservation Science in Museum, 2, 19-25. (in Korean with English abstract) https://doi.org/10.22790/CONSERVATION.2000.2.0019