Papers by Author: Yuan Xue

Abstract: A semi-interpenetrating polymer network was fabricated from SMPU (Shape-Memory Polyureathan and PNIPAM (poly (N-isopropylacrylamide)) with the method of in-situ crosslinking polymerization. The temperature-sensitivity of the semi-IPN films was investigated and discussed. The morphology was achieved by extracting the SMPU phase. The influence of PNIPAM phase to the phase transition behavior of SMPU was studied with DSC, the results of which showing that the phase transition temperature is increased by PNIPAM. The introduction of PNIPAM also endows the semi-IPN films with a temperature-sensitive surface hydrophilicity, which was proved by water contact angle measurement at different temperatures. Finally, the water vapor permeability evaluation reveals the temperature-sensitive transportation property of the semi-IPN films, which is formed by the swelling and shrinking of PNIPAM phase according to the environmental temperature. These results shows that the semi-IPN material is a good candidate for the fabrication of intelligent breathable garments.

Abstract: As a special animal fiber, yak hair has many excellent properties, such as soft feeling, good elasticity, gentle glossy and excellent warmth retention performance, therefore, it has very high industrial value, and can be used as high-grade raw materials in the woolen industry. In this paper, the fineness, length, curl and surface morphology of Yak fiber were analyzed, and mechanical and tensile properties with the different conditions were discussed and compared.

Abstract: This paper studied the mechanical behavior of composite yarn fabrics and pure cotton yarn fabrics with the conditions of small deformation, then making some comparison. KES-F (Kawabata Evaluation System for Fabric) system was used in the research process. The study shows that the fabric samples made of composite yarn exhibit noticeable improvement on mechanical property after using composite yarn. The results lay a solid foundation for the application and extension of composite yarn fabrics.

Abstract: Comparing the crystal orientation of the structure, tensile properties, boiling water shrinkage rate between difference filament rolls in the same spinning position spun by WINGS POY system and tradition ACW POY system, it is found that there are differences in orientation degree, crystallinity, tensile strength, elongation at break, initial modulus and boiling water shrinkage rate between difference filament rolls in the same spinning position. Coefficient of variation of the experimental values of WINGS POY system is lower than traditional ACW POY system.

Abstract: Microporous membranes were prepared by immersion precipitation phase inversion method from the semi-interpenetrating polymer network (semi-IPN) of shape memory polyurethane (SMPU) and poly (N-isopropylacrylamide) (PNIPAM). The influence of material compostion and preparation procedure on the morphology of membranes such as pore structure and porosity was investigated by methods including Fourier-transform infrared (FT-IR) spectroscopy and scanning electronic microscopy (SEM). Both sponge-like structure and large-pore structure were found in the membranes. The introduction of PNIPAM content in the semi-IPN promotes the formation of large-pore structures and increases the porosity of membranes, due to the improvement of water diffusion into the casting solution. We also found that by increasing the temperature of coagulation bath and the concentration of DMF in the coagulation solution, the formation of large pores could be impeded, and membranes with more sponge-like structure could be prepared.

Abstract: Thermo-sensitive polyurethane (TSPU) was synthesized from poly(ε-caprolactone) and 4,4’-methylenebis (phenyl isocyanate) by a two-step process with 1,4-butanediol as the chain extender. Following that, a novel temperature-sensitive material was created by the strategy of IPN from TSPU and PNIPAAm in the method of in situ polymerization. The chemical structure and thermo properties of the semi-IPN were characterized with FT-IR and DSC. The results prove that intensive inter-molecular interactions exist between TSPU and PNIPAAm chains, which have significant influence on the phase transition behaviors of the material. According to these results, the transition temperature of the semi-IPN can be adjusted in the range of 30~40 °C by controlling the composition of TSPU and the semi-IPNs.

Abstract: This paper studied the mechanical behavior of the filament/staple fiber composite yarn and the pure cotton yarn under the isostress and isostrain of cycling tensile strength with the conditions of small deformation. And it also analyzed the elastic recovery rate, creep rate and stress relaxation rate under the different deformation rate and load. The results show that the mechanical properties of elastic recovery rate, stress relaxation and creep all keep in good range in the experiment of cycling tensile strength with low certain elongation and constant load; as the increase of certain elongation and constant load, the mechanical properties of elastic recovery rate, stress relaxation and creep have much difference, just in terms of the conformality under the cyclic tensile strength, PET/PU/cotton composite yarn shows the best, next is the PU/cotton composite yarn, and then next is the PET /cotton composite yarn, and the pure cotton yarn shows the worst.

Abstract: The two component filament/staple fiber core-spun yarn is spun on FA506 ring spinning frame with PTT filament as interlaced yarn and Tencel staple fiber as outer sheath. The spinning process and process parameters were analyzed. The morphology, mechanical property and wear-resisting property of two component core-spun yarn were tested. Results indicate that elastic recovery rate of core-spun is up to 90.6%; broken strength is up to 20 cN/tex after boiling water treatment. The core-spun yarn can be used as a new kind of knitting yarn for sweater.

Abstract: Aggregation structure and properties such as crystallinity, orientation, mechanical properties, boiling water shrinkage of high-shrinkage component, low-shrinkage component, and the bi-shrinkage yarns which are spun at different process conditions are characterized and tested. The high-shrinkage component and low-shrinkage component spin individually, the bi-shrinkage yarns spun by one-step spinning process. The research indicates that with the spinning speed increases, the degree of crystallinity and orientation of the high-shrinkage component increases, and its tensile strength increases, elongation at break decreases, boiling water shrinkage attain the highest value when the spinning speed is 3,000 m/min; With draft ratio decreased, the orientation, crystallinity, tensile strength, initial modulus of the low shrinkage component decrease, and its elongation at break, boiling water shrinkage increases; as the draft ratio decrease, BSY crystallinity decreased, orientation first increases, then decreases, strength, initial modulus decrease slightly, boiling water shrinkage increases; H1 increases from 80 °C to 95 °C, BSY crystallinity gradually increased; degree of orientation decrease, strength, initial modulus increases and elongation decreases, boiling water shrinkage increases firstly,and decreases slightly afterwards; with the H2 temperature increases, BSY crystallinity increase, orientation first increased and then decreased slightly,the tensile strength reduce a little, elongation at break increase, initial modulus decreased, boiling water shrinkage decreased.

Abstract: N-isopropylacrylamide(NIPAAm) was dispersed in polyurethane(PU) solution and crosslinked with N,N’-methylene bisacrylamide(BIS) to form a semi-interpenetrating polymer networks. The synthesized solution was casted into water bathes with and without 0.25M sodium chloride to get a microporous film by wet phase inversion process. The ratios of BIS amount to N-isopropylacrylamide were varied. The structure and properties of polyurethane/ poly(N-isopropylacrylamide) (PU/PNIPAAm) composite film were characterized by differential scanning calorimetry (DSC) and scanning electron microscope (SEM). The swelling behavior of PU/PNIPPAm composite films was evaluated. The results showed that the addition of sodium chloride lower the LCST of PNIPAAm and the PU/PNIPAAm composite films exhibit temperature sensitivity under swollen conditions.