Preparation And Characterization Of Functional Fibers In Indoor Formaldehyde Decontamination

Due to the change of architectural and decorative materials,the indoor air condition is becoming worse and worse.WHO(World Health Organization) has ranked indoor air pollution in top ten killers to human's life.Since formaldehyde is the most dangerous pollution in air contaminations,which is a big threaten to people's health,so how to decontaminate formaldehyde and improve the indoor air environment have attracted great attention.The functional ramie was prepared to absorb and degrade formaldehyde.The function was based on the catalyze ability of chlorohemin and absorbent ability of ramie.The first step was grafting of chlorohemin onto ramie. According to experiment results,the optimal conditions were the following:chlorohemin concentration was 1g/L,the temperature was between 130℃-140℃,and the reaction time was around 3-4min, then functional ramie with the grafting rate of 0.35%could be got. Measured by Scanning Electronic Microscope,FT-IR spectrums and X-ray diffraction spectrums,the differences between grafted ramie and the original ones proved the grafting and deposit of chlorohemin onto ramie.Because of the crystallity decrease of ramie,it was substantiated that chlorohemin was grafted not only on the surface of fiber,but only in the disorder areas of ramie.Airtight container was made to analyze the formaldehyde-decontaminating effect of this functional fiber.The experiment showed that when the initial concentration of formaldehyde was 1ppm and the concentration of oxygen was 21%,35.8%,65.4% and 95%respectively,the sample with grafting rate of 0.35%could absorb and degrade formaldehyde by 60.4%,70.5%,75.9%and 80.8%correspondingly.So the decontaminating effect was in direct proportion to the concentration of oxygen.What's more,the formaldehyde-decontaminating effect was better when the functional ramie contained moisture.On the other hand,the room temperature paid the opposite effect on the formaldehyde-decontaminating ability of functional fibers.Repeated experiments proved this kind of fiber could be used permanently.In a 10L container,the functional fiber could also be effective.In order to know whether the original physical property of ramie had changed or not after the grafting process,experiments on hydroscopic property,mechanical property and bending rigidity of the fibers had been done.The results showed that the functional fiber had a lower moisture regain rate because of the decrease of hydroxide radical in ramie and covering of grafting stuff.The moisture regain rate of functional fiber(grafting rate:0.35%) was 7.81%,with a decrease rate of 20%.Due to the destroy of some crystal regions and the less connection between molecules,rupture strength and the elongation at break of functional fibers were smaller than that of the original ramie,decreased by 6.28%and 1.59% respectively,where the grafting rate of functional ramie was 0.35%. Since chlorohemin was grafted in the loose area of ramie,so the CV of results reached 30.11%.And the bending rigidity of the functional ramie was decreased,which proved that the ramie was less stinging after the grafting process.