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Opto structural effects of annealing of Nylon 66 fibers  [PDF]
I.M. Fouda,F.M. EL-Sharkawy
Optica Applicata , 2004,
Abstract: Multiple-beam Fizeau fringes are used to study the changes in optical parameters of annealed Nylon 66 fibers. Changes in the refractive indices and birefringence of skin and core have been measured interferometrically. The application was carried out using multiple-beam Fizeau fringes in transmission to determine the principal optical parameters characterizing the skin-core layers. The density of the fibers was measured by a system based on the theory of vibrating strings. The results of density and optical measurement were used to calculate the degree of crystallinity, the form birefringence, the number of monomeric units per unit volume, the harmonic mean polarizability of the dielectric, the harmonic mean specific refractivity and the virtual refractive index. The results also were used to obtain the stress-optical coefficient Cs, the optical configuration parameter Da, the mean square density fluctuation , the segment anisotropy gs, molar refractivity R and the thermal stress s in different annealing conditions. The results clarify the reorientation, and layer changes occuring due to annealing conditions. The optical orientation function and the angle of orientation are also calculated. Relations between the optical parameters with different thermal effects are discussed.
Amorphous and crystalline phase interaction during the Brill transition in nylon 66
eXPRESS Polymer Letters , 2009, DOI: 10.3144/expresspolymlett.2009.55
Abstract: A prominent α' process in specifically treated nylon 66 and microcomposite samples is identified by dynamic mechanical analysis and proposed to be an amorphous phase counterpart of the Brill transition identified by synchrotron wide-angle X-ray diffraction (WAXD). It is suggested that this α' process, which marks a critical free volume change and an onset of segmental chain movement in the amorphous phase, precedes and prompts the Brill transition in the crystalline phase.
Ortho-to-para ratio of NH2. Herschel-HIFI observations of ortho- and para-NH2 rotational transitions towards W31C, W49N, W51 and G34.3+0.1  [PDF]
C. M. Persson,A. O. H. Olofsson,R. Le Gal,E. S. Wirstr?m,G. E. Hassel,E. Herbst,M. Olberg,A. Faure,P. Hily-Blant,J. H. Black,M. Gerin,D. Lis,F. Wyrowski
Physics , 2015,
Abstract: We have used the Herschel-HIFI instrument to observe both nuclear spin symmetries of amidogen (NH2) towards the high-mass star-forming regions W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4) and G34.3+0.1. The aim is to investigate the ratio of nuclear spin types, the ortho-to-para ratio (OPR), of NH2. The excited NH2 transitions are used to construct radiative transfer models of the hot cores and surrounding envelopes in order to investigate the excitation and possible emission of the ground state rotational transitions of ortho-NH2 N_(K_a,K_c} J=1_(1,1) 3/2 - 0_(0,0) 1/2 and para-NH2 2_(1,2) 5/2 - 1_(0,1) 3/2$ used in the OPR calculations. Our best estimate of the average OPR in the envelopes lie above the high temperature limit of three for W49N, specifically 3.5 with formal errors of \pm0.1, but for W31C, W51, and G34.3+0.1 we find lower values of 2.5\pm0.1, 2.7\pm0.1, and 2.3\pm0.1, respectively. Such low values are strictly forbidden in thermodynamical equilibrium since the OPR is expected to increase above three at low temperatures. In the translucent interstellar gas towards W31C, where the excitation effects are low, we find similar values between 2.2\pm0.2 and 2.9\pm0.2. In contrast, we find an OPR of 3.4\pm0.1 in the dense and cold filament connected to W51, and also two lower limits of >4.2 and >5.0 in two other translucent gas components towards W31C and W49N. At low temperatures (T \lesssim 50 K) the OPR of H2 is <10^-1, far lower than the terrestrial laboratory normal value of three. In such a "para-enriched H2" gas, our astrochemical models can reproduce the variations of the observed OPR, both below and above the thermodynamical equilibrium value, by considering nuclear-spin gas-phase chemistry. The models suggest that values below three arise in regions with temperatures >20-25 K, depending on time, and values above three at lower temperatures.
Thermal Properties and Crystallite Morphology of Nylon 66 Modified with a Novel Biphenyl Aromatic Liquid Crystalline Epoxy Resin  [PDF]
Zhiqi Cai,Shuang Mei,Yuan Lu,Yuanqi He,Pihui Pi,Jiang Cheng,Yu Qian,Xiufang Wen
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms141020682
Abstract: In order to improve the thermal properties of important engineering plastics, a novel kind of liquid crystalline epoxy resin (LCER), 3,3',5,5' -Tetramethylbiphenyl-4,4' -diyl bis(4-(oxiran-2-ylmethoxy)benzoate) ( M1) was introduced to blend with nylon 66 ( M2) at high temperature. The effects of M1 on chemical modification and crystallite morphology of M2 were investigated by rheometry, thermo gravimetric analysis (TGA), dynamic differential scanning calorimetry (DSC) and polarized optical microscopy (POM). TGA results showed that the initial decomposition temperature of M2 increased by about 8 °C by adding 7% wt M1, indicating the improvement of thermal stability. DSC results illustrated that the melting point of composites decreased by 12 °C compared to M2 as the content of M1 increased, showing the improvement of processing property. POM measurements confirmed that dimension of nylon-66 spherulites and crystallization region decreased because of the addition of liquid crystalline epoxy M1.
Evaluación experimental en ratas del comportamiento biológico y mecánico del Nylon 66 para cerclaje en ortopedia
Izquierdo,D; Zunino,J H; Semiglia,G;
Archivos de medicina veterinaria , 2006, DOI: 10.4067/S0301-732X2006000300013
Abstract: steel wires are currently being successfully used in stabilization and fixation of several kinds of fractures in both human and animal orthopedic surgery. in addition, new ceramic and plastic derivates have become available for those purposes. in oder to assess biocompatibility and to evaluate mechanical performance of sterilized nylon 66 compared to the standard 316l steel wire, an experimental study in rat tibiae was carried out. nylon 66 was looped extraperiostically around the right tibiae and steel was placed around the left tibiae , in the same animal. different procedures (autoclave, formalin and ethylene oxid ), were used to sterilize nylon 66. mechanical properties (from deformation to rupture) of differently sterilized nylon 66 were then quantitatively compared. non-sterelized nylon 66 served as control. to validate sterilizing procedures, microbiologic tests were performed on all sterilized nylon 66. results showed that both nylon 66 and steel wires failed to induce cellular reaction (inflammation) at the implant sites. mechanical testing of sterilized nylon showed that formalin-exposed or autoclaved wires were quantitatively similar, and also similar to controls. conversely, ethylene-oxid-sterilized material showed less resistance to deformation. results were analyzed with a non-parametric statistical test (kruskal-wallis). all sterilized nylon 66 samples failed to demonstrate microbiologic growth in cultures at 72 hours. thus, nylon 66 could be proposed as an acceptable alternative to steel for use in fracture fixation in small animal orthopedic surgery, since it shares the same biocompatibility and resistance to mechanical deformation properties with the standard (steel). furthermore, it is an inexpensive material, widely available, and technically easy to handle. further studies should be performed, however, to verify the results in long-term implanted material.
Evaluación experimental en ratas del comportamiento biológico y mecánico del Nylon 66 para cerclaje en ortopedia Evaluation of biological and mechanical performance of Nylon 66 in rats for cerclage in orthopedic surgery  [cached]
D Izquierdo,J H Zunino,G Semiglia
Archivos de medicina veterinaria , 2006,
Abstract: A efectos de evaluar la biocompatibilidad y el comportamiento mecánico del Nylon 66 en comparación con el acero inoxidable para su utilización en cirugía ortopédica, dise amos un experimento en ratas. El Nylon 66 fue usado como "cerclaje" supraperióstico en la tibia derecha y el alambre de acero, en la tibia izquierda del mismo animal, en un grupo de 18 ratas. Para el estudio de sus propiedades mecánicas, el Nylon 66 fue esterilizado con diferentes métodos (autoclave, vapores de formalina y gas de óxido de etileno). Las referidas propiedades (deformación hasta ruptura) de los precintos de Nylon 66 esterilizados con distintos métodos fueron comparadas cuantitativamente. El Nylon 66 no esterilizado fue usado como control. A efectos de la validación de los diferentes métodos utilizados, se realizaron controles microbiológicos de todos los materiales esterilizados. Los resultados de nuestro experimento mostraron que ni el Nylon 66 ni el Acero 316L indujeron respuesta celular (inflamación) a nivel de sus sitios de implante. El testado mecánico del Nylon 66 demostró que el material esterilizado con formalina o autoclavado, tuvo un comportamiento cuantitativamente similar, así como también respecto al control. Sin embargo, el material esterilizado con gas de óxido de etileno mostró menor resistencia a la deformación. Estos resultados fueron analizados estadísticamente con el test no paramétrico de Kruskal-Wallis. Los cultivos microbiológicos de 72 horas de las muestras de Nylon 66 esterilizadas con diferentes métodos resultaron negativos. El Nylon 66 podría, pues, proponerse como un material aceptable de alternativa para la fijación de fracturas en Cirugía Ortopédica de peque os animales, en virtud de haber demostrado compartir con el estándar (acero), biocompatibilidad y resistencia a la deformación mecánica. Asimismo, se trata de un material económico, muy accesible en el mercado y técnicamente de muy sencilla manipulación. Ulteriores estudios se hacen necesarios sin embargo, para corroborar nuestros resultados en material implantado durante largos períodos de tiempo. Steel wires are currently being successfully used in stabilization and fixation of several kinds of fractures in both human and animal orthopedic surgery. In addition, new ceramic and plastic derivates have become available for those purposes. In oder to assess biocompatibility and to evaluate mechanical performance of sterilized Nylon 66 compared to the standard 316L steel wire, an experimental study in rat tibiae was carried out. Nylon 66 was looped extraperiostically around the right tibiae a
Preparation and properties of carbon fiber-Ni/nylon 66 composites

- , 2017, DOI: 10.13801/j.cnki.fhclxb.20160706.003
Abstract: 为制备低电阻率的尼龙66基复合材料,以碳纤维和镍粉(Ni)填充尼龙66制备碳纤维-Ni/尼龙66高导电复合材料。研究填料表面改性和含量对碳纤维-Ni/尼龙66复合材料导电性能和力学性能的影响。结果表明:KH550改性碳纤维和Ni有助于降低碳纤维-Ni/尼龙66复合材料的电阻率。碳纤维-Ni/尼龙66复合材料的电阻率随着碳纤维和Ni含量的增加而减小,且碳纤维和Ni填充尼龙66的导电逾渗阈值均为20 wt%,此时制备的碳纤维-Ni/尼龙66复合材料的电阻率为455 Ω·cm,熔融温度为202.2℃。碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度随着碳纤维或Ni含量的增加而先增大后减小。当Ni含量为20 wt%时,碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度在碳纤维含量分别为20 wt%和10 wt%时达到最大值,分别为98 MPa和70 MPa;当碳纤维含量为20 wt%时,碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度则在Ni含量为30 wt%和20 wt%时达到最大值,分别为120 MPa和67 MPa。 In this study, in order to obtain nylon 66-based composites with low electrical resistivity, carbon fiber-Ni/nylon 66 composites were prepared by a plastic extruder with carbon fiber (CF) and nickel powder (Ni) as the paddings, nylon 66 as the raw resin. The relationships of the surficial modification and the fractions of CF and Ni between the electrical resistivity and mechanical properties of CF-Ni/nylon 66 composites were studied. The results show that the modification by KH550 and increasing of CF and Ni are of advantage to decrease the electric resistivity of CF-Ni/nylon 66 composites. And the electrical percolation thresholds of CF and Ni both are 20 wt%. The electric resistivity of CF-Ni/nylon 66 composite is 455 Ω·cm at the percolation thresholds, and its melting point is 202.2℃. The flexural strength and tensile strength of CF-Ni/nylon 66 composites increase firstly and decrease lately with the increasing of CF and Ni. When the fraction of Ni is 20 wt%, the flexural strength of CF-Ni/nylon 66 composite reaches to the maximum 98 MPa as the fraction of CF is 20 wt%, and the tensile strength reaches to the maximum 70 MPa as the fraction is 10 wt%. When the fraction of CF is 20 wt%, the flexural strength of CF-Ni/nylon 66 composite reaches to the maximum 120 MPa as the fraction of Ni is 30 wt%, and the tensile strength reaches to the maximum 67 MPa as the fraction is 20 wt%. 深圳市知识创新计划(JCYJ20130402161506238)
Effect of Some Navels on Properties of Cotton/Nylon66 Blend (1?:?1) Rotor Spun Yarn and Wrapper Formation: A Comparison between Rotor and Ring Spun Yarn  [PDF]
Babak Yadollah Roudbari,Safdar Eskandarnejad
Journal of Textiles , 2013, DOI: 10.1155/2013/262635
Abstract: Use of nylon/cotton blend yarn in military uniform is common and due to advantages in its fabric in comparison to 100% cotton fabrics, capabilities of military uniforms have been improved. In this study the effects of navel type on properties of (50%-50%) nylon/cotton blend yarn and wrapper formation were investigated and compared with similar ring spun yarn. Rotor spun yarn was produced on a single head laboratory rotor spinning machine with four navels (smooth, spiral, 3 grooved, and 4 grooved) and ring yarn was produced on a zinser 319 ring spinning machine. Test result showed that navel type has a significant effect on yarn strength and strength of smooth navel yarn was maximum. Elongation of a 100% cotton rotor spun yarn is more than similar ring yarn, but it was not observed in cotton/nylon blend. Yarn irregularity and imperfections varied significantly with navel type and for rotor yarns were more than the ring yarn. Navel type had significant effect on yarn hairiness but it didnot have an effect on yarn abrasion significantly. 1. Introduction The use of blended yarn has increased significantly these days. Blending is used as a means of substituting a less expensive fiber for a highly priced one and to produce yarns with qualities that cannot be obtained by using one type of material alone. El-sheikh [1] reported that the properties of blended yarns depend on their constituent fibers and also showed that blended yarn’s tenacity decreases as the percentage of high tenacity fiber is increased. Kemp and Owen [2] investigated the stress/strain characteristics and cotton fiber breakage for a series of nylon/cotton blended yarns at strain above the breaking strain of all cotton and also studied the strength and mechanical behavior of nylon/cotton blended yarn and they found that a dependence exists between the behavior of the two fiber types. Gibson et al. [3] worked on military uniform and reported that nylon/cotton blend is used as an outer shell in different version of military chemical protective uniforms. And some researchers [4–6] worked on battle dress uniforms (BDU) and found that nylon/cotton blend is more suitable than those of any other blends. Kong et al. [7] reported that by adding 2–4% elastan yarn (lycra) through the nylon/cotton fabrics, the ability of extension of these kinds of fabrics can be increased up to 50% and it is appropriate for military uniforms. Javadiyan et al. [8] worked on seven different nylon/cotton blend ratios and reported that by increasing the nylon fiber blend ratio, the yarn elongation, abrasion resistance,
Electrostatic flocking technology and sound insulation properties of nylon 66 fibers/aluminium alloy 6061 composite plates

- , 2015, DOI: 10.13801/j.cnki.fhclxb.20150210.001
Abstract: 为研究不同植绒工艺条件下尼龙66纤维/6061铝合金复合板的植绒性能与隔声性能, 首先, 采用静电植绒工艺将6061铝合金板与尼龙66纤维复合, 制成隔音复合板;然后, 研究了植绒时间、植绒电压、极板间距以及胶黏剂涂覆量等工艺参数对植绒面密度和植绒纤维耐磨性能的影响;最后, 利用混响室-消声室法研究了尼龙66纤维/6061铝合金复合板在不同入射声频下和不同纤维结构参数时的隔声性能.结果表明:在0~40 s植绒时间范围内, 随着植绒时间的延长, 植绒面密度持续增大, 而后保持不变;同时, 在0~90 kV电压范围内, 随着电压的增加, 植绒面密度连续增大, 而后因极板间距不同植绒面密度增大或减小;植绒纤维的耐磨性能随胶黏剂涂覆量的增加而提高, 但当涂覆量超过155 g/m2后会产生气泡;当植绒时间为40 s、植绒电压为90 kV、极板间距为11.5 cm且胶黏剂涂覆量为155 g/m2时, 尼龙66纤维/6061铝合金复合板的性能最好.该复合板具有较高的中高频隔声性能, 隔声量在500~1 600 Hz频率范围内满足6 dB/倍频程规律;在2 000 Hz后出现吻合效应.提高植绒面密度以及减小尼龙66纤维直径均可增大该尼龙66纤维/6061铝合金复合板的隔声量.研究结论可为建筑用新型隔音复合材料的开发与应用奠定基础. In order to investigate the flocking performances and sound insulating properties of nylon 66 fibers/aluminium alloy 6061 composite plates under different flocking technology conditions, aluminium alloy 6061 plates and nylon 66 fibers were composited to prepare the sound insulation composite plates by electrostatic flocking technology. Then, the effects of processing parameters such as flocking time, flocking voltage, plate distance and adhesive coating amount et al on flocking areal density and wearability of flocking fibers were investigated. Finally, the sound insulation properties of nylon 66 fibers/aluminium alloy 6061 composite plates under different frequencies of incoming audio and with different structural parameters of fibers were investigated by reverberation-anechoic chamber method. The results show that in the flocking time range of 0-40 s, the flocking areal density increases continuously with the flocking time increasing and then remains unchanged. While in the voltage range of 0-90 kV, with the increasing of voltage, flocking areal density increases continuously and then increases or decreases for the difference of plate distance. Wearability of flocking fibers increases with the increasing of adhesive coating amount, but after the coating amount surpasses 155 g/m2, the gas bubbles generate. When the flocking time is 40 s, flocking voltage is 90 kV, plate distance is 11.5 cm and adhesive coating amount is 155 g/m2, the nylon 66 fibers/aluminium alloy 6061 composite plates have the best properties. The composite plates have preferable sound insulating properties at medium and high frequencies, sound reduction index goes with the rule of 6 dB/octave within the frequency range of 500-1 600 Hz, and the tally effect occurs after 2 000 Hz. The sound reduction index of the nylon 66 fibers/aluminium alloy 6061 composite plates can be enhanced by increasing the flocking areal density and decreasing the nylon 66 fiber diameter. The research conclusions can lay the foundation for the
Preparation and sound absorption properties of nylon 66 fiber-Q235 steel composite plate based on electrostatic flocking technology

- , 2016, DOI: 10.13801/j.cnki.fhclxb.20150528.001
Abstract: 采用静电植绒技术制备尼龙66纤维-Q235钢复合板, 并研究了不同黏结剂涂覆量对植绒牢度的影响, 通过SEM观察分析绒毛层的形貌, 并通过传递函数法测量200~6 300 Hz频率范围内复合板的吸声性能, 分析植绒电压、植绒时间、极板间距和纤维形态结构对吸声性能的影响。结果表明:植绒牢度随黏结剂涂覆量的增大而增大, 在不产生气泡的前提下, 100 g/m2为最佳涂覆量;吸声性能随植绒电压的增加而提高, 但增幅逐渐减小, 最终趋于稳定;植绒时间对吸声性能的影响趋势同植绒电压相似;吸声性能随极板间距的增大而降低, 开始下降缓慢, 随后逐渐加快, 其最优植绒参数为植绒电压90 kV、植绒时间40 s、极板间距10 cm;纤维形态结构也对尼龙66纤维-Q235钢复合板的吸声性能有明显影响, 减小纤维长度和纤维直径均可提高复合板的吸声系数, 最佳纤维形态结构参数为长度0.9 mm、直径20 μm。 The nylon 66 fiber-Q235 steel composite plate was made by electrostatic flocking technology, and the effect of different amount of adhesive coating on flocking fastness was studied. The morphology of villi layer was observed and analyzed by SEM, and the sound absorption properties of composite plate were measured by transfer function method in the frequency range of 200-6 300 Hz. The influences of flocking voltage, flocking time, plate spacing and fiber morphology structure on the sound absorption properties were analyzed. The results show that, flocking fastness increases with the increasing amount of adhesive coating, on the premise of no air bubbles, 100 g/m2 is the best coating amount. As flocking voltage increasing, sound absorption properties improve, change rate decreases and finally tends to be stable. As plate spacing increasing, sound absorption properties decreases, begins to decline slowly, then gradually speeds up. The best flocking parameters are flocking voltage of 90 kV, flocking time of 40 s, plate spacing of 10 cm. Fiber morphology structure also has obviously influence on the sound absorption properties of nylon 66 fiber-Q235 steel composite plate. Reduce the fiber length and fiber diameter both can improve the sound absorption coefficient of composite plate, the best fiber morphology structure parameters are length of 0.9 mm, diameter of 20 μm. 江苏省科技支撑计划(BE2013124); 江苏省科技成果转化基金(BA2013063); 江苏高校优势学科建设工程(PAPD)
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