Preparation And Properties Of Humidity Control Materials Based On Konjac Glucomannan

Humidity control material is relying on its own adsorption and desorption properties,according to the changes in the humidity of the air space, automatically adjust the air relativehumidity. Humidity control materials are the eco-friendly materials, without consumingelectricity and other non-renewable energy sources, with good ability to automatically adjust thehumidity. It saves energy, improve the environment of comfort, to promote sustainabledevelopment of ecological environment has important significance.Designed to the structure ofhumidity control materials and prepared efficient humidity control materials, established a clearrelationship between the structure and properties of materials. To study the mechanism ofhumidity control materials.Conducive the materials development and industrialization,realization of preventive protection of cultural relics.Our group focus on resolving the problemsof microenvironment humidity control in conservation cultural relics.We conducted a pre-studyof developing humidity control materials.Three different structures humidity control materials with different structures which used anatural polysaccharide polymer-konjac glucomannan (KGM) and inorganic nanotube compositefiber material-halloysite nanotubes (NHTs) were prepared in this paper. And we use differentmethods to modify KGM and NHTs. There are some problems of he previous humidity materialproblems (Such as the preparation of complex, structural instability, poor absorption anddesorption properties, humidity is not ideal) we had prepared. We improved and optimized thehumidity control materials. The performance is more stable of the material has been prepared.Study the different components of the composite material, the impact of different structural.Wehave conducted morphology, structure characterization, adsorption and desorption performancetesting, performance testing using simulated microenvironment of the three different structureshumidity control materials. And study the effects of different structural materials for itshygroscopic properties. Development of high moisture absorption capacity, adsorption anddesorption rate, stable performance, with a range of different humidity humidity material, themain research results are as follows:In the crosslinking of KGM/NHTs composite humidity control material system,the thermally activated halloysite in the material dispersed unevenly, materials with low moistureadsorption rate, halloysite can promote moisture desorption. The best halloysite proportion is2%, the rate of moisture adsorption and desorption rate were22.79%and76.02%. The materialhumidity controlling curve rises with the increase of the amount of halloysite, stability becomespoor. When the composite material (10%,20%content of halloysite) pretreatment moisturecontent is about5%, humidity can be stable between40to55%. It can meet the usingrequirements (low humidity requirement about40%).To research crosslinking KGM-g-PAAS/NHTs humidity composite materials show thatacid activation halloysite has a best moisture adsorption rate, thermal activation halloysiteproperties of composite materials is the best, after KH590modified halloysite dispersed in theorganic phase well. Different modified halloysite has little effect on the adsorption anddesorption properties of composites and can not afford a decisive role. KH590modifiedhalloysite composite materials, with increasing amounts of halloysite adsorption and desorptionperformance drop after the first increase, when the halloysite content of4%to achieve the bestperformance, respectively,117.29%and73.41%. It can be seen form the composite materials inmicro-environmental humidity adjustment curves, through grafting sodium polyacrylate,humidity stability of the composite material has been greatly improved, and the result ofhumidity is good, and equilibrium moisture is stable. When the composite material waspretreated humidity20-40%, the final stable environment humidity is49.4-57.1%RH, to meetthe requirements.Successfully prepared nanoscale crosslinked microspheres KGM uniform particle size.Through characterization shows that particle size is between40-50nm, stable performance. Bywater vapor adsorption curve shows the microspheres, the microspheres after KGM modification,its adsorption and desorption performance greatly improved, the moisture content increased from0.22g/g to0.89g/g, desorption rate increased74.7percent to95.0%. The microenvironmenthumidity curve shows that when the moisture content is10%of microspheres, the equilibriumhumidity is between53%-55%in range of the ideal humidity, and equilibrium humidity isstable. Crosslinked konjac glucomannan microspheres have a stable structure, good adsorptionproperties, pretreatment simple, and has a strong ability to adjust the different humidity. It hasthe most outstanding performance and a broad application space. It is important to the textileheritage of preventive protection.