Olsson Anne-Mari, Salmén Lennart
STFI, Swedish Pulp and Paper Research Institute, Box 5604, SE-114 86 Stockholm, Sweden.
Carbohydr Res. 2004 Mar 15;339(4):813-8. doi: 10.1016/j.carres.2004.01.005.
The nature of water sorption to different materials has always been a complex matter to address, partly due to the different possibilities of hydrogen-bond formation. For cellulosic materials this is extremely important for its product performance. In order to gain a deeper understanding of the moisture adsorption mechanisms of cellulose and hemicelluloses, the molecular interaction between moisture and paper and between moisture and some wood polymers was studied using FTIR spectroscopy under stable humid conditions. It was found that all the moisture-sorbing sites adsorbed moisture to the same relative degree, and that the rate of adsorption was the same for all these sites. It was also noticed that the moisture is adsorbed in the form of clusters. A direct relationship was found between the moisture weight gain and the increase in the absorbance peaks for humidities up to 50% relative humidity after which the moisture gain increased faster, a fact that still remains to be explained.
不同材料对水的吸附性质一直是一个难以解决的复杂问题，部分原因在于形成氢键的可能性不同。对于纤维素材料而言，这对其产品性能极为重要。为了更深入地了解纤维素和半纤维素的吸湿机制，在稳定的潮湿条件下，使用傅里叶变换红外光谱法研究了水分与纸张之间以及水分与一些木材聚合物之间的分子相互作用。研究发现，所有吸湿位点对水分的吸附程度相同，且所有这些位点的吸附速率相同。还注意到水分以簇的形式被吸附。研究发现，在相对湿度高达50%之前，吸湿增重与吸光度峰的增加之间存在直接关系，在此之后吸湿增重增加得更快，这一事实仍有待解释。
