Study On Preparation And Performance Of Humidity-controlling Materials

It is of great significance to develop high-performance humidity control material with high moisture content and fast humidity adjusting property to realize the preventing protect of cultural heritages. This study aims at the preparation of a humidity control material which can regulate the relative humidity of micro-environment at the range of50%±5%and has high moisture content and high humidity adjusting speed. A natural hygroscopic polymer was modified by grafting to increase its moisture absorbance and humidity control performance with the loading of a kind of inorganic mineral which possesses a unique one-dimensional nano-pipeline structure. In addition, different foaming methods were applied with the purpose to prepared composite humidity control material presenting better humidity control performance.After heating at different temperatures, the heat activated natural clay silicate mineral--halloysite nanotubes (HNTs) with the best humidity control property were composited with konjac glucomannan (KGM), a natural polymer which has many reactive hydroxyl used for graft polymerization with acrylic acid, and therefore a kind of organic/inorganic nano-composite humidity control material was prepared. Aluminum hydroxide, urea, PEG (6000) were utilized as foaming agent to prepared composite humidity control materials with porous structure. The humidity control performances of the prepared materials were evaluated. And the micro-surface feature, structure, etc. were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric (TG), etc.It has been found that:the humidity control properties of the heat treated HNTs were improved; the organic/inorganic nano-composite humidity control material could fast adjust the relative humidity of micro-environment at the range of50%±5%with the moisture absorption rate of122%and moisture desorption rate of103%, which could be called as a high-performance humidity control material; the foaming processes by aluminum hydroxide, urea, PEG (6000) were not fully worked, but still we can say that the humidity control performances of the materials prepared under150℃were better than those of prepared under80℃, as a whole.