| With the improvement of people's living standard,more and more attention has been paid to the residential environment.People spend most of their time indoors working or studying.Being in VOCs environment for a long time will do great harm to people's health,and cause a series of diseases such as headache,fatigue and chest tightness.Therefore,the treatment of VOCs has become an imminent problem.In the thesis,Adsorptive polypropylene nonwovens and polypropylene fibers were prepared by impregnation and melt spinning respectively.The reduction of graphite oxide,viscosity of impregnating solution,friction resistance,mechanical properties,kinetics and thermodynamics of Xylene Adsorption and adsorption mechanism of impregnated polypropylene nonwovens prepared by impregnation method were studied.In the melt-spun fiber part,the pulverization effect of activated carbon,rheological properties of blends and the structure and mechanical properties of fibers of the two products,especially the dynamism of xylene adsorption by fibers,were discussed respectively.The structure and morphology of activated carbon,graphite oxide,impregnated polypropylene fabric and adsorption fiber were characterized by X-ray diffraction,Raman spectroscopy,infrared spectroscopy and scanning electron microscopy.The results show that:(1)The viscosity of impregnating solution is related to the content of activated carbon and graphite oxide.The microporous structure in activated carbon increases the viscosity of chlorinated polypropylene impregnating solution,while layered graphite oxide decreases the viscosity of the solution.The increasing size,distortion and hydrophobic aggregation of reduced graphite oxide all result in the increase of the viscosity of the solution.(2)The breaking strength of polypropylene nonwovens treated by impregnation method increases and the elongation at break decreases.(3)The adsorption processes of xylene on activated carbon,graphite oxide and their mixture-coated polypropylene nonwovens follow Lagergren's quasi-second-order adsorption kinetics equation,and the adsorption of polypropylene nonwovens impregnated with activated carbon/graphite oxide observe Langmuir isothermal adsorption equation.It is diffusion of xylene in polar binder molecules that controls the adsorption process,resulting in an increase in the adsorption activation energy.(4)PP/EVA/AC blends with 3.75%and 5%activated carbon have good spinnability at 230?,POY spinning speed at 2800 m/min and roller drafting ratio at 1.4.When the adsorption temperature was at 323K,the adsorption capacity of the two blended polypropylene fibers reaches over 390mg/g.(5)Lagergren's Quasi-first-order kinetic equation can well fit the adsorption process of xylene on polypropylene fibers.The adsorption between adsorbate and adsorbent belongs to physical adsorption.Polar chlorinated polypropylene molecules directly lead to a significant difference in p-xylene behavior between impregnated nonwovens and melt-spun polypropylene fibers.The major feature and innovation of the thesis:(1)Based on melt-spinning and drawing techniques,high adsorption PP/EVA/AC blend fibers were first prepared.Which show good mechanical properties and excellent xylene adsorption,and can be used as packaging materials for furniture and chemical building materials,as well as interior decoration materials for indoor and transportation vehicles.(2)The polypropylene nonwovens made of chlorinated polypropylene,which combines crushed activated carbon with graphite oxide mixture,have good friction resistance,high tensile strength and good adsorption.(3)A simple test device for xylene adsorption was built.Based on the ideal gas equation of state,the kinetics and thermodynamic behaviors of vapor phase adsorption of impregnated polypropylene nonwoven fabric were determined.The experimental results show that the test device is practical,and the data are scientific and reliable.This provides a new method for evaluating the gas adsorption performance of adsorbents. |
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