Research On Preparation And Properties Of Luffa Filling Composite

As people's awareness of environmental protection and resource increasingly drying up,the renewable,biodegradable composite was prepared by biomass resources as raw materials of green received extensive attention from the scientific community and industry.As a kind of natural plant fiber material with abundant resources and excellent structure,luffa fiber has a great application potential in the field of filling materials.It is of great practical significance for promoting sustainable development and environment-friendly society to strengthen the high-efficient and high-value diversified utilization of biomass resources.For promoting the recycling of industrially discarded luffa resources and preventing environmental pollution caused by the incineration of luffa waste,abundant luffa scraps and environmentally friendly EVA resin and polyester fibers were used as raw materials to produce luffa fiber sound absorbing composites by the clean hot-pressing technology.The compressive mechanical property,acoustic property,antibacterial property and pressure-relief were tested to provide a scientific theoretical basis for the application of luffa filling composite in the field of home furnishing.The quasi-static compression,repeated loading and supporting properties of luffa filling composites were tested and compared with sponge,latex and other plant fiber composites.Acoustic impedance tube was used to test the performance of sound absorption coefficient of luffa filling composites,and the influence of different adhesive matrix,material thickness,material density and back air gap thickness on the sound absorption coefficient of luffa complex filling materials were investigated.By comparing the chemical components of the petroleum ether extract of luffa fiber by GC-MS and SSNMR,the inhibition degree of different chemical pre-treatment of luffa fiber powder to E.coli was studied to determine its antibacterial property.The pressure distribution test system was used to investigate the influence of the luffa filling composite on the pressure distribution of human-chair interface,so as to verify the effect of the pressure-relieving of the luffa filling composite in the practical application,and provide a scientific theoretical basis for the practical application design of the luffa filling composite in common seats.The main conclusions of this paper are as follows:(1)By hot-pressing at low temperature(Temperature:105?:Pressure:1Mpa;Time:6min).According to the mass ratio of luffa/EVA(1:1),a green and environment-friendly filling material with good supporting properties and moisture absorption and dispersion properties was prepared.The compressive strength,peak stress and energy absorption per unit volume of the luffa/EVA filling composite increased with the increase of density.Among them,the surface firmness of luffa/EVA filling composite is the smallest,and gradually increases from the surface to the bottom.However,the firmness of each layer of the three kinds of luffa/EVA filling composite with different experimental densities is lower than those of jute filling materials,3D jute filling materials and palm filling materials.When the luffa/EVA filling composite receives external force,it has good anti-deformation ability with soft texture and good support performance.(2)The moisture absorption of luffa/EVA filling composite with density of 0.11 g/cm³ and0.12 g/cm³ is better than palm filling material and the moisture dispersion of luffa/EVA filling composite within the scope of all the experimental density is better than that of jute filling material,3D jute filling material and palm filling material,it shows that luffa/EVA filling composite can not only absorb moisture timely by human in the sitting position,but also keep human-mat interface in a dry state and improve the sitting comfort.More importantly,the luffa/EVA filling composite can also timely distribute the absorbed moisture to the surrounding environment,avoiding the sticky and wet feeling on the surface of the material,otherwise is prone to the breeding of bacteria,mildew and other problems,thus affecting the performance and the service life of the product.(3)The sound absorption coefficient of luffa/low-melting-point polyester fiber filling composite is also better than that of luffa/EVA resin filling composite.When the prepared luffa/low-melting polyester fiber filling composite with density of 0.09g/cm³,thickness of 4cm,and back air gap thickness of 2cm,the average sound absorption coefficient of the filling material reaches 0.645,which is an efficient sound absorption material.After hot-pressing,the inner space of luffa filling composite formed a three-dimensional network structure with a large number of tiny gaps connected with the external environment.The surface of low-melting-point polyester fiber became rough,and there were a lot of wrinkles,cracks and pore structures.There were also a lot of crack structures on the surface of EVA resin.In addition,the surface of luffa fiber had its own holes.The porous filling composite is very beneficial to the absorption of sound energy.(4)After 18 hours of shaking and mixing,the inhibition rates on Escherichia coli of untreated luffa fiber powder and chemical pre-treatment of Na OH+CH₄N₂O?Na OH+H₂O₂?Na OH+CH₃COOH were 44.28%,6.02%,-34.93%and 58.43%,respectively.Luffa petroleum ether extract is mainly some acids,esters and alkanes,but also contains a certain amount of alcohols,amines,squalene,squalane and other effective chemical components.The chemical pre-treatment can effectively remove some waxy layers on the surface of luffa fiber,pectin in the amorphous area and other nutrients that are conducive to microbial growth,and oleic acid,palmitic acid and other effective antibacterial components were retained.At the same time,a large number of holes were found in the cell wall layer of the luffa fiber after chemical pre-treatment,which also provided a favorable internal growth environment for E-coli and other microorganisms.Therefore,the inhibition effect of luffa fiber on the growth of E-coli is affected by many factors,which should be taken into account comprehensively such as the change of the chemical composition and relative content of the luffa fiber,and the morphology of luffa fiber after different chemical pre-treatments.(5)Luffa/EVA filling composite is more suitable for the type of seat without filling material.For the seat whose surface has been covered by filling material,its pressure-relieving effect is not obvious.There were no significant differences in contact area,pressure exponent,maximum pressure and average pressure(P>0.05),indicating that there was no significant pressure-relieving effect on the seat pan of the office chair,while there were significant differences among the various pressure indexes of the backrest,indicating that the luffa/EVA filling composite had a good effect on the backrest of the office chair.The pressure-relieving effect of EVA/luffa filling composite is better than office chair in the effect of slowing down the pressure of wooden chair.Luffa/EVA filling composite can enhance the support of the backrest of wooden chair to the waist of human body,effectively increase the contact area within the low threshold pressure range of the human-chair interface,and significantly reduce the contact area within the middle and high threshold pressure range,so as to make the majority of human body contacted with seat are in a low pressure state.After covered with luffa/EVA filling composite,the pressure exponent,maximum pressure and average pressure of the backrest and seat pan of the wooden chair were significantly reduced,which effectively reduced the external pressure on the human body and made the human-chair interface in a relatively low pressure state,indicating that it had a good effect of pressure-relieving on the backrest and seat pan of the wooden chair.