TEMPO-mediated Preparation Of Oxidized Cellulose Template Zr/Si Aerogel And Its Application In Thermal Insulation Textiles

Thermal insulation materials have been an indispensable part of human development for a long time.Traditional methods increase the weight of materials and stack thickness to improve the thermal insulation performance,not only the effect is not obvious,but also the prepared thermal insulation materials have various restrictions in terms of application.The development of thermal insulation materials with high performance,simple preparation,less materials,and light weight can not only improve the thermal insulation effect significantly,but also have a wider range of applications.Among them,aerogel materials with low density and high porosity have become a new focus in the field of thermal insulation materials because they can store a large amount of air inside.Among them,cellulose aerogel is particularly prominent.It has the good thermal insulation properties of traditional silica aerogels,and does not have the shortcomings of fragility and inability to be reused.This makes it more widely used.And because cellulose is easy to modify fibers and fibers,it can be modified by inorganic materials to overcome its shortcomings such as inability to withstand high temperatures.At the same time,cellulose is degradable and will not burden the environment after use.On the other hand,cellulose can also be combined with textiles,the composite material produced will not affect the performance of the fabric,and can meet the requirements of wearing.In this paper,we intend to prepare a cellulose aerogel with high porosity and good degradability,and modify it with inorganic substances to make it have good thermal insulation properties in high temperature environments.The prepared aerogel is combined with a traditional fabric to prepare a composite aerogel thermal insulation fabric.Firstly,the cellulose is modified,then the hydrogel is prepared by the sol-gel method,and then the hydrogel is freeze-dried to prepare the aerogel.First,2,2,6,6-tetramethylpiperidine oxide(TEMPO)is used to oxidize and modify bleached kraft softwood pulp to prepare cellulose microfibers(CMF);then pass through Zr⁴⁺and Zr⁴⁺/SiO₂ sol before CMF was modified by body solution to prepare cellulose hydrogel;finally,the hydrogel was freeze-dried to obtain Zr and Zr/Si hybrid cellulose aerogel.The cellulose is modified by the ratio of different reaction materials,the reaction temperature,the reaction time,and the p H of the reaction,and then the optimal modification conditions are determined by the conductivity titration method.Prepare different aerogels with different concentrations of precursor solutions,and then conduct density,specific surface area,microstructure,Fourier infrared,X-ray diffraction,thermogravimetric,and infrared thermal imaging analysis tests on the prepared samples to determine the best.The solution ratio.The results show that the prepared aerogel can convert Zr⁴⁺into heat-resistant oxide under high temperature environment.The addition of SiO₂ can not only increase the traditional aerogel structure,but also improve the heat resistance;Zr⁴⁺metal cation induces CMF fiber Self-crosslinking forms hydrogel.TG and XRD indicate that Zr⁴⁺and Zr^4+/SiO₂ are attached to the surface of cellulose,forming a high temperature resistant layer;Zr/Si cellulose aerogel is better than Zr cellulose aerogel in high temperature environment Has better heat insulation and high temperature resistance.In order to combine the prepared cellulose aerogel and fabric to produce a composite aerogel fabric,the surface of three types of fabrics:polyester-cotton blended plain woven fabric,PP meltblown nonwoven fabric,and PP spunbonded nonwoven fabric Perform plasma treatment.Then,the fabric and hydrogel are poured into a mold together by coating and pouring,and after cross-linking each other,they are freeze-dried.Three aerogel composite fabrics with different thicknesses were prepared.After infrared thermal imaging tests,it was found that the mid-thickness PP spunbond nonwoven aerogel composite fabric had the best thermal insulation effect.The prepared composite aerogel fabric was analyzed by Fourier infrared and X-ray diffraction.It was found that the aerogel layer and the fabric were well bonded,the surface was combined by intermolecular forces,and inorganic materials such as Zr and Si were attached to the aerogel composite fabric.good.Through testing thickness,strength,breathability,abrasion resistance,and washing resistance,it is found that the thickness of the composite aerogel fabric is moderate,the strength after modification is not obvious compared with the original fabric,and the thermal insulation performance remains good after repeated abrasion and washing.From various analyses,it is concluded that the composite aerogel fabric has excellent thermal insulation performance.