The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component P...The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component PU porous elastic mixture(PPEM).The curing properties of the single-component PU and PPEM were studied with Fourier transform infrared spectroscopy(FTIR)and Marshall test.The mechanical properties of PPEM were explored via the following tests:rutting test,3-point bending test,soaked Marshall stability test,freeze-thaw splitting test,and Cantabro test.The effects of a water bath on the stability of aggregate-PU/asphalt mortar-aggregate systems were evaluated through a pull-out test and a shear test.The results show that the recommended mixing temperatures of toluene diisocyanate and methylene diphenyl diisocyanate range from 75 to 80℃and from 64 to 68℃,respectively.Room temperature(25℃)can be adopted as the compacting temperature of PPEM.PPEM can be fully cured in 4 d.Nevertheless,the water sprinkle method can obviously shorten the full curing time of PPEM.PPEM exhibites good resistance to rutting,brittle cracking,and raveling.The adhesive and shear strength of aggregate-PU/asphalt mortar-aggregate systems are negatively related to water bath duration.展开更多
Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morph...Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morphology observation, MTT and DNA assay were used to evaluate the influence of the composite on the morphology, growth and proliferation of cultured L-929 cells. Results: The composite did not impair the morphology of cultured cells in vitro. MTT and DNA assay demonstrated that the growth and proliferation of the cultured cells were not significantly inhibited by the composite. Conclusion : The composites have fine cytocompatibility and are safe for clinical use of reconstruction of chest wall defects.展开更多
Nowadays, oil spills have led to a serious environmental crisis of the world. To deal with this problem, inspired from super-hydrophobic lotus leaf, this study fabricated super-hydrophobic and super-lipophilic functio...Nowadays, oil spills have led to a serious environmental crisis of the world. To deal with this problem, inspired from super-hydrophobic lotus leaf, this study fabricated super-hydrophobic and super-lipophilic functionalized graphene oxide/polyurethane （FGP） sponge by a simple and inexpensive dip coating method. The resulting FGP sponge was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and water contact angle. The results expressed that FGP sponge exhibited a similar surface structure to that of a lotus leaf, and possessed the super-hydrophobic characteristic with the water contact angle （WAC） of 152°± 1 °. The absorption capacity and reusability were also investigated. It can be seen that, the FGP sponge can remove a wide range of oils and organic solvents from water with good absorption capacities （up to 35 times of its own mass）. Significantly, after 10 cycles the absorption capacity of the oils and organic solvents was higher than 90°; for the reused FGP sponge, demonstrating the good reusability of the FGP sponge. Therefore, this study probably provided a simole way to remove the pollutions ofoil spills and toxic organism from water.展开更多
基金The Fundamental Research Funds for the Central Research Institute (No. 2020-9054)。
文摘The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component PU porous elastic mixture(PPEM).The curing properties of the single-component PU and PPEM were studied with Fourier transform infrared spectroscopy(FTIR)and Marshall test.The mechanical properties of PPEM were explored via the following tests:rutting test,3-point bending test,soaked Marshall stability test,freeze-thaw splitting test,and Cantabro test.The effects of a water bath on the stability of aggregate-PU/asphalt mortar-aggregate systems were evaluated through a pull-out test and a shear test.The results show that the recommended mixing temperatures of toluene diisocyanate and methylene diphenyl diisocyanate range from 75 to 80℃and from 64 to 68℃,respectively.Room temperature(25℃)can be adopted as the compacting temperature of PPEM.PPEM can be fully cured in 4 d.Nevertheless,the water sprinkle method can obviously shorten the full curing time of PPEM.PPEM exhibites good resistance to rutting,brittle cracking,and raveling.The adhesive and shear strength of aggregate-PU/asphalt mortar-aggregate systems are negatively related to water bath duration.
基金Supported by the Sci & Tech Development Foundation of Shang-hai (No. 024419076)
文摘Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morphology observation, MTT and DNA assay were used to evaluate the influence of the composite on the morphology, growth and proliferation of cultured L-929 cells. Results: The composite did not impair the morphology of cultured cells in vitro. MTT and DNA assay demonstrated that the growth and proliferation of the cultured cells were not significantly inhibited by the composite. Conclusion : The composites have fine cytocompatibility and are safe for clinical use of reconstruction of chest wall defects.
基金Supported by the National Natural Science Foundation of China(21776319)
文摘Nowadays, oil spills have led to a serious environmental crisis of the world. To deal with this problem, inspired from super-hydrophobic lotus leaf, this study fabricated super-hydrophobic and super-lipophilic functionalized graphene oxide/polyurethane （FGP） sponge by a simple and inexpensive dip coating method. The resulting FGP sponge was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and water contact angle. The results expressed that FGP sponge exhibited a similar surface structure to that of a lotus leaf, and possessed the super-hydrophobic characteristic with the water contact angle （WAC） of 152°± 1 °. The absorption capacity and reusability were also investigated. It can be seen that, the FGP sponge can remove a wide range of oils and organic solvents from water with good absorption capacities （up to 35 times of its own mass）. Significantly, after 10 cycles the absorption capacity of the oils and organic solvents was higher than 90°; for the reused FGP sponge, demonstrating the good reusability of the FGP sponge. Therefore, this study probably provided a simole way to remove the pollutions ofoil spills and toxic organism from water.
