Papers by Keyword: Nylon 6

Abstract: Radiation cross-linking of polymers is a good modification method of modifying the properties of polymers, especially mechanical properties. The mechanical properties of non-irradiated and irradiated nylon 6 samples by beta rays were measured at the ambient and elevated temperature for comparison. The tested samples showed noticeable changes of mechanical behavior between ambient (23°C) and elevated (80°C) temperature and between non-irradiated and irradiated samples. It is possible to use these results in the practice because they clearly shows that radiation cross-linking influences the mechanical properties in most ways positively.

Abstract: The blends of Nylon 6/Acrylonitrile-Butadiene-Styrene (ABS) with styrene-maleic anhydride (SMA) was prepared by melt blending as the compatilizer. Mechanical properties, dynamic mechanical analysis (DMA) and fracture appearances were determined. It was found that the impact and tensile strength firstly increased and then decreased along with the increase of the SMA content. The properties reached maximum values when the content of SMA was 1.5%. The results of DMA and scanning electron microscope (SEM) indicated that the addition of SMA can effectively enhance the compatibility of Nylon 6 and ABS. Key words: Nylon 6, ABS, SMA, blends, modification

Abstract: Through the polymerization and grafting reaction of bisphenol A dianhydride and bisphenol A diamine, the polyimide activator (PI activator) of acyl caprolactam end capping is obtained and then the anionic in-situ polymerization modified nylon 6 resin is obtained. Viscosity analysis shows that PI consumption is higher than 0.1 (of monomer mass), the reaction temperature is higher than 160°C, the viscosity rises rapidly in a short time and the rapid polymerization molding can be realized; when PI consumption is higher than 0.15 (of monomer mass), the water absorption of matrix resin will be lower than 1.4%; compared with the nylon resin, its water absorption is significantly lowered and its mechanical property is improved greatly; microscopic analysis shows that PI molecules fail to enter the crystalline phase of the nylon 6 and form lamellar crystals in the nylon matrix, which plays a role of enhancement and obstruction; differential thermal analysis shows that PI reduces the melting enthalpy and melting point temperature of nylon 6 resin, which indicates that PI reduces the crystallization capacity of nylon 6.

Abstract: The new kind of bio-based nylon 56 fiber has been synthesized by adipic acid and 1,5-pentanediamine, which was prepared by fermenting a variety of starch in straw. The resistance of the nylon 56 fiber to acid need to be studied because the problem of nylon fabrics often encounter reactions of chemical reagents in their processing, finishing and dressing. The factors of acid concentration, temperature and time affect the mechnical behavior of the fibers of nylon 56 ,nylon6 and nylon 66. Strength of all three nylon fibers have obvious decrease if treated in acetic acid concentration of 10 g/L, while have a straight line down if treated in acetic acid concentration of 100 g/L as time increases until to a half falling down at 120 minutes. Bio-based nylon 56 fibers treated in acetic acid concentration of 100 g/L for 30 minutes have a sharp reduction and almost lost its function at 50 minutes.

Abstract: The new kind of bio-based nylon 56 fiber has been synthesized by adipic acid and 1,5-pentanediamine, which was prepared by fermenting a variety of starch in straw. The resistance of the nylon 56 fiber to acid need to be evaluated because the problem of nylon fabrics often encounter reactions of chemical reagents in their processing, finishing and dressing. Temperature and concentration play the main role on the alkali resistance among the factors that influence alkali resistant of nylon fibers: temperature, time, and concentration of alkali. Strength lose of bio-based nylon 56 and nylon 6 are slightly larger than that of nylon 66 when treated in caustic soda of 100 g/L at 98°C for 120 minutes, which means that nylon 56 fiber have good alkali resistant.

Abstract: This study aims to examine the influence of the temperatures of heat treatment on the puncture-resistance of Nylon6/LPET compound nonwoven fabrics. Polyamide 6 (Nylon 6) fibers and low-melting-point polyester (LPET) fibers are combined and undergo a heat treatment to make three-dimensional (3-D) Nylon 6/LPET compound nonwoven fabrics through a nonwoven process. The nonwoven fabrics are tested for their dynamic puncture resistance, constant rate puncture resistance, and impact strength. The experiment results show that when thermally treated at a high temperature, the compound nonwoven fabrics are rendered with a lower dynamic puncture resistance and a lower constant rate puncture resistance, but a greater impact strength.

Abstract: Kinetic parameters are calculated based on the reactive temperature rise curve measured by adiabatic approach at the temperature of 145 to 160 °C with the catalytic system of NaOH and acyl caprolactam End-capped butadiene-acrylonitrile rubber (CHTBN) or styrene-butadiene rubber (CHTBS). The reaction order is first order, the activation energy is between 72.91−73.16 kJ∙mol⁻¹ and the pre-exponential factor is between 3.22×10¹¹− 3.38×10¹¹ mol¹⁻ⁿ∙s⁻¹ in the system of CHTBN/NaOH. While in CHTBS/NaOH, the reaction order is between 1.23-1.34, the activation energy is between 85.55－86.88 kJ∙mol⁻¹ and the pre-exponential factor is between 4.52×10¹¹−5.0 9×10¹¹ mol¹⁻ⁿ∙s⁻¹. The adiabatic reaction kinetic model of caprolactam anion was constructed based on the existing research findings, by which the polymerizing reaction is simulated. The coincidence between the simulation results and the experimental data revealed that the model is reasonable and correct.

Abstract: Kinetic parameters were calculated based on the catalytic reaction systems of sodium caprolactam salt、N-75 biuret and at the temperature of 145 to 160 °C. The reaction order was approximately first order. The activation energy was between 73.2−77.1 kJ∙mol⁻¹ and the pre-exponential factor was between 2.9×10¹¹−3.6×10¹¹ mol¹⁻ⁿ∙s⁻¹. The calculated reaction heat of 134.5−137.3 J∙g⁻¹ was in consonance with the literature value of 138.6 J∙g⁻¹. The adiabatic reaction kinetic model of caprolactam anion was constructed based on the existing research findings. The coincidence between the simulation results and the experimental data revealed that the model was reasonable and correct.

Abstract: To study the influence of spandex on combustion behavior of textile fabrics, two kinds of nylon 6 fabrics were tested using cone calorimeter test and vertical burning test. Some key combustion parameters such as heat release rate (HRR), total heat release (THR) and rate of smoke release (RSR) were obtained from cone calorimeter test and afterflame time and damaged length from vertical burning test. Results indicated that the nylon 6 fabric containing spandex showed 21% higher HRR value. But THRs of the nylon 6 fabric containing spandex and the pure nylon 6 fabric were close. RSR curves indicated that RSR value of the nylon 6 fabric containing spandex was 73% higher than that of the pure nylon 6 fabric. The afterflame time and damaged length of the nylon 6 fabric containing spandex were much longer than that of the pure nylon 6 fabric. Spandex does accelerate the combustion behavior on Nylon fiber.

Abstract: In recent years, as global technical progress grows, many mechanized machines are developed continuously. Mechanization has substituted for manpower in many factories for promotion of production efficiency, leading to mechanical noise happening more severely. If people are subjected to noise pollution for long term, they would happen dysphoria and absent mindedness, resulting in accident occurrence. Therefore, how to effectively reduce noise pollution becomes an urgent subject. Moreover, rapid population development and fast-growth economy raise consumption in every country, driving industry into high-production and high-consumption times and meanwhile generating much of wastes. In order to achieve sustainable development, these wastes should be recycled effectively. Therefore, 20 wt% recycled PET fibers were added in this study. This paper mainly used 3D and 15D Nylon fibers (70, 60, 50, 40, 30 wt%), low-melting PET fibers (10, 20, 30, 40, 50 wt%) and 20 wt% high-strength PET fibers, to fabricate Nylon 6/Low melting PET/ Recycled high-strength PET nonwoven via needle-punching process. After that, tensile strength, air permeability and sound absorption coefficient property of resulting nonwoven were tested and then evaluated respectively.