颗粒尺寸对注塑铁氧体/尼龙12复合材料流动性和磁性能的影响

制备颗粒尺寸不同的铁氧体磁粉,采用混炼工艺制备铁氧体/尼龙复合材料,研究了颗粒尺寸对复合材料流动性和磁性能的影响,结果表明,当铁氧体大小颗粒尺寸之比大于4时,两者级配可以使复合体系获得最佳的流动性.对颗粒尺寸影响机理的研究表明,小颗粒的尺寸下限在0.5μm附近,大颗粒尺寸上限在5μm附近,当大、小颗粒及尼龙体积分数分别...     

碳─尼龙纤维混杂改性水泥基复合材料的力学性能研究

对碳纤维─尼龙纤维混杂改性水泥基复合材料研究表明，该方法是提高水泥基复合材料强度和韧性的最有效方法。进一步研究表明：在纤维总掺量较大情况下，水泥基复合材料中碳纤维─尼龙纤维混杂使抗弯强度，冲击性韧性呈负混杂效应，结合抗弯、抗拉条件下荷载─变形曲线试验研究，作者对两种纤维混杂增强、增韧作用机理进行分析，认为：高弹纤维、低弹纤维各项参数相匹配及水泥基体改性可以获得更好的混杂改性效果。     

MC尼龙/Dy_2O_3纳米复合材料非等温结晶动力学

采用差示扫描量热法研究铸型(MC)尼龙/Dy_2O_3纳米复合材料的非等温结晶行为,并利用Caze法和Mo法对结晶动力学进行分析,运用Kissinger方法计算MC尼龙的结晶活化能.结果表明,纳米Dy_2O_3起到异相成核的作用,使MC尼龙的结晶峰温升高,结晶总速率增大;添加纳米Dy_2O_3使MC尼龙的结晶活化能增大.     

表面活性剂对钛酸四丁酯整理尼龙6织物的影响

根据水热合成技术,在以钛酸四丁酯为前体物时,通过添加表面活性剂来控制生成的纳米二氧化钛颗粒尺寸,同时直接对尼龙6织物表面进行整理改性,并使用活性染料对织物进行染色。测试了织物的透气性、光泽度、拉伸性能以及色牢度等,研究了不同种类表面活性剂对钛酸四丁酯整理尼龙6织物服用和染色性能的影响。结果表明,经整理改性的织物断裂强力和断裂伸长率增大,十二烷基苯磺酸纳使织物光泽度提高,壳聚糖使织物透气性下降最少。     

A new mechanism for the electrospinning of nanoyarns

A new electromechanical mechanism for spinning “core electrospun nanoyarn” is researched, designed, and implemented. SEM images have shown that the deposited nanofibers were wrapped helically around the core filament resulting in a core electrospun nanoyarn. The parameters of this mechanism such as feed‐in angles, twist rates, and take‐up speeds are analytically investigated. Twist rates of 500 to 750 revolutions per minute, core feed‐in angle of 0°, and take‐up speed of 1.5 cm/s were found optimum for successfully producing core electrospun nanoyarn. This nanoyarn is expected to find many applications in industrial and medical textiles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.     

Synthesis and application of a sulfur‐containing phosphoric amide flame retardant for nylon fabric

A sulfur‐containing flame retardant (SFR) was synthesized from polyphosphoric acid, epoxy chloropropane, and thiourea. Using a water‐soluble isocyanate‐terminated (WIT) cross‐linker, the flame retardant was applied as a flame‐retardant finishing on nylon fabric. WIT is a compound that not only cross‐links SFR and nylon cellulose but also contains no formaldehyde. Comparisons of the main performances of SFR with those of N‐methyloldimethylphosphonopropionamide (known as ‘Pyrovatex CP’) and a bicyclic phosphonite (known as ‘Antiblaze 19T’) indicate that the presence of sulfur in SFR plays a crucial role in decreasing the flammability of the nylon fabric. The limiting oxygen index value and damaged carbon length of the finished nylon fabric were 29.4% and 5.7 cm, respectively, when the concentrations of SFR and WIT were 200 and 40 g/L, respectively, and the baking temperature and time were 150 °C and 3 min, respectively. After 10 laundry cycles, the fabric still retains some flame retardancy. Copyright © 2016 John Wiley & Sons, Ltd.     

Morphology and crystallization behavior of nylon 6‐clay/neat nylon 6 bicomponent nanocomposite fibers

Nylon 6‐clay hybrid/neat nylon 6, sheath/core bicomponent nanocomposite fibers containing 4 wt % of clay in sheath section, were melt spun at different take‐up speeds. Their molecular orientation and crystalline structure were compared to those of neat nylon 6 fibers. Moreover, the morphology of the bicomponent fibers and dispersion of clay within the fibers were analyzed using scanning electron microscopy and transmission electron microscopy (TEM), respectively. Birefringence measurements showed that the orientation development in sheath part was reasonably high while core part showed negligibly low birefringence. Results of differential scanning calorimetry showed that crystallinity of bicomponent fibers was lower than that of neat nylon 6 fibers. The peaks of γ‐crystalline form were observed in the wide‐angle X‐ray diffraction of bicomponent and neat nylon 6 fibers in the whole take‐up speed, while α‐crystalline form started to appear at high speeds in bicomponent fibers. TEM micrographs revealed that the clay platelets were individually and evenly dispersed in the nylon 6 matrix. The neat nylon 6 fibers had a smooth surface while striped pattern was observed on the surface of bicomponent fibers containing clay. This was speculated to be due to thermal shrinkage of the core part after solidification of the sheath part in the spin‐line. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39996.     

无卤阻燃增强高流动性尼龙6的研究

采用高流动性尼龙(PA)6为原料,制备了一系列玻璃纤维(GF)增强无卤阻燃PA6材料。考察了材料配方和挤出工艺对改性材料阻燃性能、力学性能、热性能及熔体流动速率(MFR)的影响,并对其原因进行了分析。结果表明,与普通PA6相比,高流动性PA6由于熔体黏度低、MFR高,有利于无卤阻燃剂和GF在基体材料内的混合和分散,因此在同样配方和工艺条件下,显示出更好的阻燃效果与更优的力学性能。     

双恶唑啉及环氧类扩链剂对PA6的改性效果比较

通过熔融挤出的方法分别用环氧类扩链剂和双恶唑啉类扩链剂对尼龙(PA)6进行扩链增黏,并对扩链产物的特性黏度,力学性能和加工性能等进行了测试,对比了两类扩链剂对PA6的改性效果。结果表明,当这两类扩链剂的质量分数均为0.9%时,PA6的各项性能最佳;双恶唑啉类扩链剂对PA6的改性效果比环氧类扩链剂要好。相对于纯PA6,添加质量分数为0.9%的双恶唑啉类扩链剂,可使扩链PA6的特性黏度由0.86 d L/g增加到1.57 d L/g,熔体流动速率由14.3 g/10 min降到5 g/10 min,缺口冲击强度由5.5 k J/m2增加到7.3 k J/m2,拉伸强度由54 MPa增加到65.85 MPa,断裂伸长率由130%增加到450.9%,弯曲强度由53.16 MPa增加到72.66 MPa,平衡扭矩由2.1 N·m升高到5.3 N·m。