Study On The Gelatification Process And Properties Of Alginate Fiber Nonwovens

The content of this paper is on the gelation of alginate fiber nonwoven fabric was modified,to explore the modification process and the optimal modification conditions.The modification mechanism was analyzed by infrared spectroscopy,XRD,ion concentration test and so on.Using the same process to modify seaweed / copper ammonia nonwoven fabric.Through the experiment to determine the optimal modification conditions.Of the modified mask base cloth and popular film of face of base cloth for basic performance,absorption performance,the liquid performance,metal absorption performance multi-angle comparison.To provide a theoretical basis for the development of this new type of mask.Experiments are now get the following results:The seaweed fiber nonwovens by first processing in low concentration HCl solution,and then rinsed with ethanol to neutral,gelation modification method of final treatment at low concentrations of NaOH in ethanol solution,seaweed fiber nonwovens in the water immediately after gel.In the experimental environment,the HCl concentration was 0.10%,at room temperature,processing time is 30min;the concentration of NaOH was 4mmol/L,the ethanol solution treatment temperature of30 ℃,processing time is 1H for the best gelation modification conditions.The water keeping properties of the best seaweed fiber textiles gel can reach more than 16g/g,much higher than the non gel nonwovens.Gelation modification mechanism: the treatment with hydrochloric acid aqueous solution destroyed the crystalline structure of nonwoven fabrics,and reduced the crystallinity and Ca2+ concentration;however,the lactone bonds between the fiber molecules were formed on the basis of the catalyzed effect of hydrochloric acid.The treatment with the sodium hydroxide/ethanol solution improved hydrolytic fractures of the lactone bonds,and further reduced the crystallinity and Ca2+ concentration of nonwoven fabrics.As a result,water molecules can diffuse into the larger gaps between fiber molecules and the three-dimensional network structures were formedby the interactions of hydrogen bond forces,resulting in the gel formation of calcium alginate nonwoven fabrics.The physical properties of the nonwoven fabric before and after modification were found:the physical properties such as thickness,mass per unit area,air permeability and fracture strength were not different before and after modification.Through the microscope to nonwovens best gel properties in the fiber diameter increased 2.5 times,the thickness and volume of the film were increased to 5 times by macroscopic photograph.The swelling rate and the swelling rate of seaweed gel have a great relationship with the gel degree.The greater the gel degree,the slower the swelling rate of the gel,that is,the smaller the slope of the swelling curve,and the shorter the gel degree is,the shorter the time to reach the swelling equilibrium.The better the gel degree is,the slower the rate of gel expansion is,that is,the slope of the curve is smaller,and the lower the gel degree is,the shorter the time to complete dehydration is.In order to make alginate mask substrate transform into gel immediately when they absorbed liquid,alginate fibre/cuprammonuium mask substrate were modified through two steps,and compare it with 5 kinds of mask on the market.The results show that the modified mask substrate surface density is 31.44g/m~2,the thickness is only 0.12 mm,the permeability reached 4317.80mm/s,compared with the traditional mask,not only "light","thin",but also more breathable.The evaporation loss of modified mask is the smallest,evaporation rate is only 26.07%.The amount of water in the 20 min to reach 0.04g/cm~2,a mask can be added 10.68 g moisture to the skin.As a new type of mask,alginate fibre/ cuprammonuium mask has excellent ability to adsorb metal,adsorption capacity of cadmium is up to 1.35mg/cm~2,which is a new type of functional mask.