Yongzhu Cui

Research on sound absorption properties of multilayer structural material based on discarded polyester fiber

Thermoplastic polyurethane was reinforced with discarded polyester fiber to develop excellent mechanical properties of fiberboard composites, by hot pressing and mixing method. The fiberboard was drilled and made as a perforated plate, which was then coupled with polyester fabric; so a multiple layer structural material with good sound absorption function was achieved. Sound absorption properties were studied by changing holes diameter, air cavity depth, and perforation ratio. Theoretical absorption coefficient was obtained through building analytical model and massive theoretical calculation. It was found that it has good agreement with the experimental results. Hence, the analytical model could be adopted to predict the sound absorption coefficient of multilayer structural composites.

Immobilization of modified hydroxyapatite particles onto PET filter fabric for adsorption property

Polymer chains were introduced to esterified hydroxyapatite particle surface with methacrylic acid for modification and subsequently modified particles were immobilized onto PET filter fabric via heat fusion method to impart adsorption property. The polymerization process of methyl methacrylate on esterified hydroxyapatite surface was optimized and effects of treating time, temperature, particle size, and concentration on immobilization ratio and pore size of filter fabric were discussed. FTIR were applied to characterize the structure of modified hydroxyapatite and treated PET filter fabric. TG was used to determine average chain length of grafted polymer on particles. The results showed that polymer chain with length of 13.57 (mole ratio to hydroxyapatite) was introduced to particle surface and modified particles were embedded onto PET filter fabric with a hydroxyapatite immobilization ratio of 63.6% and pore size of 102.3 µm under optimum conditions. Cadmium adsorption amount of 118.4 mg/g was achieved at the cadmium concentration of 392.8 mg/L, implying that PET filter fabric has adsorption ability toward heavy metal ions.

Effect of Micro-slit Plate Structure on the Sound Absorption Properties of Discarded Corn Cob Husk Fiber

Discarded degummed corn cob husk fiber was used as reinforced material and discarded thermoplastic polyurethane (TPU) particles were used as matrix material. The composites were fabricated by blended mastication-hot processing and the micro-slit plate having excellent absorption acoustic performance was fabricated by processing micro-slit on the composites. Sound absorption properties were studied by changing slit rate, slit width and air cavity depth. The results were choosing a smaller slit rate, a smaller slit width and a larger air cavity depth as possible to improve sound absorption coefficient in low frequency level. The double layer micro-slit plate based on corn cob husk fiber and TPU was designed to broaden sound absorption band and to have a wider application. Theoretical absorption coefficient was obtained through building analytical model and massive theoretical calculation. It was found that it had good agreement with the experimental results. Hence, the analytical model could be adopted to predict the sound absorption coefficient of the double layer micro-slit plate.

Surface Modification of Linen Fabric via UV Induced Grafting to Improve Dyeability and Wearability

ABSTRACT Linen fabric was surface modified with acrylic acid (AA) and acrylamide (AM) using diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as photoinitiator via UV induced grafting to improve dyeing performance and wearability. Effects of different mass ratios of AA and AM in monomer mixture on dyeing performance and wearability were discussed. Maximum dye uptake of 79.4% of cationic dyes was achieved when AA was grafted only and 0/100 of AA and AM could be applied to dye a light color for good color fastness. Dyeing performance of grafted fabric was also improved with reactive dyes and direct dyes. In addition, breaking strength and rigidity of grafted fabric were improved.

Coloration and Decoloration of Textiles Using a TiO2 Composite Pigment

A colorable pigment was prepared by dye adsorption onto titanium dioxide and subsequent silane coating. The effects of pH value, dye concentration, and adsorption times on dye adsorption were discussed. Large adsorption capacity of an anionic dye was obtained at pH value of 2 and the adsorption process was well described by the Langmuir isotherm model. Good dyeability and color fastness of pigment dyed fabric were achieved in the normal life cycle under sunlight. The decoloration of pigment was realized through photocatalytic degradation of dye molecules by titanium dioxide under ultraviolet irradiation when reusing the pigment dyed textiles after disposal. The new absorption peaks in the FTIR spectrum at 2924.95 cm-1, 1714.91 cm-1, 1461.17 cm-1, and 1289 cm-1 verified silane modification. Silane modification improved fixation of dyes onto the pigment and immobilization of pigments onto substrates. The close attachment of silane coating layer to titanium dioxide was conducive to photodegradation of dye molecules in the pigment.

Study of coupling agent modification of cotton stalk bast fibres reinforced polylactic acid flame–retardant composites

In this experiment, cotton stalk bast fibre was modified, respectively, with A–171, KH–550 and TC–114 coupling agent, to improve the mechanical properties of fibre board. After testing the modified fibre board for its mechanical properties and analysing coupled fibre with FT–IR, it is proved that there were some new groups introduced into the fibre. Experimental results showed that adding A–171 and KH–550 type of silane coupling agent improves the mechanics properties of the material increasingly. A–171–type silane coupling agent was better for tensile strength and bending strength of the fibre board, increased by 31 and 65%, respectively, and the notched impact strength of fibre board KH–550 silane coupling agent was larger, and could be increased by 52.2%.

Photografting of 2-(dimethylamino)ethyl methacrylate onto cellulosic material for better antibacterial property

Linen cellulosic material was grafted with 2-(dimethylamino)ethyl methacrylate(DMAEMA) using ultraviolet (UV) radiation to obtain better antibacterial property. The graft polymer was characterized and the effects of operation parameters on grafting yield and quaternization are discussed. The results showed that a maximum grafting yield of 7.26 % was obtained under the conditions standardized. It was found that an antibacterial ratio of 99 %, compared with pristine linen material, was achieved at a quaternization ratio of 70.26 %, which was supposed to be that quaternary ammonium salts with positive charges could damage the cell membrane of bacteria and kill the bacteria. The DMAEMA graft polymer increased breaking strength, rigidity and dyeability of cellulosic materials. The quaternization further enhanced dyeability of anionic reactive dyes due to more electrostatic attraction.