Synthetic dyes in the aqueous media have been commonly used for textile dyeing, resulting in resource and environmental pressure arising from consumption of water and environmentally unfriendly chemicals. In this stud...Synthetic dyes in the aqueous media have been commonly used for textile dyeing, resulting in resource and environmental pressure arising from consumption of water and environmentally unfriendly chemicals. In this study, an eco-friendly process of dyeing polyamide 6, 6(PA66) fabrics with natural Monascus pigments in decamethylcyclopentasiloxane(D5) solvent has been developed to minimize water consumption and effluent generation. The influence of processing parameters including dyeing temperature, dyebath pH and dyeing time on dyeing effects was explored. It was shown that color strength and color fastness of the samples dyed in D5 media were higher than those of the samples dyed in the aqueous media. Moreover, PA66 fabrics exhibited the highest color strength, good color fastness and a bacteriostatic rate of 53.6% against Staphylococcus aureus when it was dyed at pH of 3.5 and temperature of 80 ℃ for 30 min.展开更多
The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethyle...The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethylene/polyamide 66 (PTFE/PA66) blends were investigated by water immersion test, uniaxial tensile test, three-point test, and Charpy impact fracture test. The water-absorptivity in the blend decreases with increasing PTFE content, which indicates that the PTFE phase restrains the polyamide phase from water absorption. For water-free blends, the addition of PTFE causes a reduction in tensile strength, while for water-absorbed PTFE/PA6 blends, the tensile strength increases with increasing PTFE. Simultaneously, the absorbed water improves the elongation, but results in a notable reduction in flexural strength of the blends. Although the addition of PTFE causes a reduction in notched impact strength of the blends, as compared to pure polyamide, the absorbed water has little effects on the notched impact strength of the blends. Finally, the effects of temperature and loading frequency on complex viscosity parameters of PTFE/PA6 and PTFE/PA66 melts were tested. It is found that the complex viscosity of PTFE/PA6 melt is reversed with increasing temperature and shear velocity, but that of PTFE/PA66 melt increases approximately in exponential form with increasing temperature. To fill polyamide with suitable mass percentage of PTFE can effectively reduce the viscosity of blend, and as a result, the molding and processing properties are improved.展开更多
基金Fujian Provincial Department of Education,China(No.JAT190528)Quanzhou Science and Technology Project,China(No.2019C014R)。
文摘Synthetic dyes in the aqueous media have been commonly used for textile dyeing, resulting in resource and environmental pressure arising from consumption of water and environmentally unfriendly chemicals. In this study, an eco-friendly process of dyeing polyamide 6, 6(PA66) fabrics with natural Monascus pigments in decamethylcyclopentasiloxane(D5) solvent has been developed to minimize water consumption and effluent generation. The influence of processing parameters including dyeing temperature, dyebath pH and dyeing time on dyeing effects was explored. It was shown that color strength and color fastness of the samples dyed in D5 media were higher than those of the samples dyed in the aqueous media. Moreover, PA66 fabrics exhibited the highest color strength, good color fastness and a bacteriostatic rate of 53.6% against Staphylococcus aureus when it was dyed at pH of 3.5 and temperature of 80 ℃ for 30 min.
基金Prqject(10572123) supported by the National Natural Science Foundation of China Project(05JJ30014) supported by the Natural Science Foundation of Hunan Province, China Project(05C100) supported by the Scientific Research Fund of Education Department of Hunan Province, China
文摘The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, flexural strength, and notched impact strength of polytetrafluoroethylene/polyamide 6 (PTFE/PA6) and polytetrafluoroethylene/polyamide 66 (PTFE/PA66) blends were investigated by water immersion test, uniaxial tensile test, three-point test, and Charpy impact fracture test. The water-absorptivity in the blend decreases with increasing PTFE content, which indicates that the PTFE phase restrains the polyamide phase from water absorption. For water-free blends, the addition of PTFE causes a reduction in tensile strength, while for water-absorbed PTFE/PA6 blends, the tensile strength increases with increasing PTFE. Simultaneously, the absorbed water improves the elongation, but results in a notable reduction in flexural strength of the blends. Although the addition of PTFE causes a reduction in notched impact strength of the blends, as compared to pure polyamide, the absorbed water has little effects on the notched impact strength of the blends. Finally, the effects of temperature and loading frequency on complex viscosity parameters of PTFE/PA6 and PTFE/PA66 melts were tested. It is found that the complex viscosity of PTFE/PA6 melt is reversed with increasing temperature and shear velocity, but that of PTFE/PA66 melt increases approximately in exponential form with increasing temperature. To fill polyamide with suitable mass percentage of PTFE can effectively reduce the viscosity of blend, and as a result, the molding and processing properties are improved.
