微波预处理在古代饱水木材PEG脱水应用的初探研究

Preliminary study of application of microwave pretreatment on PEG dehydration of waterlogged wood

PEG法(聚乙二醇法)是饱水木质文物处理中比较典型的一种方法,大分子量的PEG更利于木质的长久保存,但也存在严重缺点,如PEG大分子难以进入木质内部,可能造成木质收缩,且处理周期相当长。本文以低功率微波辐射对饱水木材进行预处理,再用PEG4000浸渍脱水,结果表明:微波预处理加快了PEG大分子向木质内部迁移,尤其在非水相条件下处理60 s,木材5 cm深度处的PEG含量增加了6.82%,含水率、干缩率和干燥速度分别下降1.70%、16.13%和1.63%,不同深度处的各指标更趋于一致,提高了木材脱水定型的效果。

PEG method （polyethylene glycol method） is a typical method for the treatment of waterlogged wooden cultural relics, especially for large wooden cultural relies. PEG with large molecular weight is more conducive to the long-term preservation of wood, but also there are serious shortcomings, such as PEG is difficult to enter the internal wood and may cause wood shrinkage, besides the processing cycle is quite long. In this paper, waterlogged wood is preprocessed by low power microwave, then dehydrate by soaked in PEG4000 solution for a time. Experimental results show that compared with the untreated sample, microwave pretreatment can accelerate migration of PEG molecular to wood internal, the PEG content of wood in five centimeter depth has increased 6.82%,at the same time, moisture content, dry-shrinkage rate and drying rate have separately decreased by 1.70%, 16.13% and 1.63%, furthermore different depths of the index tends to be more consistent, so the effect of wood objects dehydration and reinforcement can be improved.