Morphology and Thermal Characteristics of Polyamide/Monosodium Glutamate Membranes

The membranes were prepared with various concentrations of polyamide and monosodium glutamate additive for dialysis application in this work. The membranes were characterized by determining creatinine diffusive permeability and by obtaining scanning electron microscope images and thermal characteristics. The results show that a membrane prepared without additive has a thick skin layer and a nonporous sublayer. The permeation of creatinine solute does not take place due to this dense (thick/nonporous) structure. When an additive is used in membrane synthesis, the thickness of skin layer reduces and voids are present, which results in permeation of this unwanted solute through the membrane.     

聚酰胺类热塑性弹性体含量对PLLA/三元聚酰胺共混物形态和性能的影响

以聚酰胺类热塑性弹性体（TPAE）为增容剂增容左旋聚乳酸（PLLA）与三元聚酰胺共混物,采用扫描电子显微镜（SEM）、差热扫描量热仪（DSC）、X射线衍射仪（XRD）等研究了TPAE含量对PLLA/三元聚酰胺（70/30,质量比,下同）共混物的形态、力学性能和热性能的影响。力学性能研究结果表明,添加TPAE后,PLLA/三元聚酰胺共混物的拉伸强度、断裂伸长率、缺口冲击强度显著提高,TPAE含量为5份时,共混物的断裂伸长率为370 %,缺口冲击强度为90 J/m,拉伸强度为39 MPa;SEM分析表明,添加TPAE后,共混物中三元聚酰胺相的粒径显著变小;DSC与XRD分析结果表明,TPAE含量对PLLA/三元聚酰胺共混物的熔融行为和结晶行为无明显影响,而共混物拉伸后,其结晶度显著提高。     

SA型透明聚酰胺的聚集态结构和热性能研究

采用固相缩聚工艺制备了一系列SA型透明聚酰胺(SATPA),对SATPA的聚集态结构和热性能进行了研究。结果表明,SATPA为非结晶性高聚物;固相缩聚能够有效地提高SATPA的耐热性,通过固相缩聚,SATPA的玻璃化转变温度(Tg)最高可由102 ℃提高到120 ℃,并且Tg随着熔体流动速率的降低而增长;SATPA的起始热分解温度都超过420 ℃,具有良好的热稳定性。     

OMMT对PA1212/PP共混物形态结构与力学性能的影响

通过熔融挤出法制备了尼龙1212 (PA1212)/聚丙烯(PP)(质量比70/30)/有机蒙脱土(OMMT)共混物.采用广角X射线衍射(WAXD)、扫描电子显微镜(SEM)等研究了OMMT在PA1212/PP共混物中的分布状态及其对PA1212/PP共混物形态结构与力学性能的影响.结果表明:在PA1212/PP/OMMT共混体系中,OMMT用量较低时,主要为剥离形态分布,当OMMT用量为7 phr时,OMMT片层主要为插层结构;随OMMT用量的增加,PP分散相尺寸逐渐减小,PA1212/PP/OMMT共混体系的强度逐渐提高,缺口冲击强度呈下降趋势.     

截面形状对聚酰胺6/石墨烯复合纤维性能的影响

通过母粒共混熔融纺丝法制备了圆形、三角形和十字形截面的聚酰胺6/石墨烯复合纤维。采用光学显微镜观察了纤维的截面形貌并计算其异形度,采用负离子测试仪、远红外发射率测试仪、恒温恒湿干燥箱表征了不同截面纤维的负离子释放性能、远红外辐射性能和纤维吸湿及其干燥速度。研究表明:圆形、三角形和十字形截面纤维的异形度分别达到6.31%、34.80%和58.29%。相对而言,异形度增大,会明显影响纤维的负离子释放浓度、吸湿速度及干燥速度,其中十字形截面纤维的负离子释放浓度最高达到1 820个/cm~3;另一方面,异形度的变化不会对纤维远红外辐射能力产生明显的影响,其远红外发射率在0.90～0.93,远红外辐射温升约为1.70℃。     

Morphology and Crystallization of Biobased Polyamide 56 Blended with Polyethylene Terephthalate

This study attempts to promote biobased polyamide 56 (PA56) as a sustainable candidate to replace commercial PA6 and PA66 when blended with polyethylene terephthalate (PET). Scanning and transmission electron microscopy of the blends with different PA56 contents reveals an immiscible morphology with an increase in the size of the dispersed domains by increasing PA56 content. The steady‐state mixing torque of the kneader is decreased to half by adding 10 wt% of PA56 to PET. Further addition of PA56 gradually increases this torque but does not surpass the neat PET sample up to 30 wt% of PA56. As revealed by microscopic dissipative particle dynamics (DPD) simulations, this gradual increase is ascribed to the difficulty to disperse larger domains of PA56 in the thermodynamically undesired PET. The results confirm that PA56 has a lubricating effect in PET. Using polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) techniques, it is shown that PA56 acts as a nucleating agent in PET. This leads to the formation of numerous small crystals in the blends as opposed to several large crystals in the neat samples. The results encourage the use of PA56 biomaterial in combination with PET in products such as bicomponent segmented pie fibers.     

多嵌段共聚聚酰胺弹性体的制备及性能研究

以己内酰胺及十二内酰胺为主体,添加一定量的聚醚型预聚体进行阴离子无规共聚,获得系列多嵌段共聚聚酰胺弹性体;通过FTIR对其分子结构进行了表征,使用DSC、TG、DMTA研究了其热性能;并研究了多嵌段共聚聚酰胺弹性体材料力学性能与聚醚型预聚体用量及分子结构的关系。结果表明:随着聚醚型预聚体用量的提高,共聚物结晶度降低,高低温缺口冲击强度和断裂伸长率大幅增加,拉伸强度有所降低,材料表现出典型的弹性体性能特征。     

The Preparation and Characterization of Silk/Gelatin Biocomposites

There is a growing interest in the use of composite materials. Silk fiber/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 10–30 wt%. Composite containing 30 wt% silk showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength, hardness of the 30% silk content composites were found 54 MPa, 0.95 GPa, 75 MPa and 0.43 GPa and 5.4 kJ/m², 95.5 Shore A, respectively. Water uptake properties at room temperature, accelerated weathering aging, irradiation, thermomechanical analysis, and degradation in soil were carried out in this experiment.     

HA／SF复合材料的制备及表征

文章采用水热合成法制备纯的羟基磷灰石,采用硝酸钙-丝素蛋白溶液与磷酸钠原位复合HA/SF复合材料。用TEM,IR,XRD进行表征,初步探讨复合材料的组成,形貌和结构。结果表明,制备的复合材料是粒径在20～50 nm之间的弱结晶针晶,其形貌和结晶度等与人体骨羟基磷灰石相似。     

马来酸酐含量及制备工艺对PA6/POE-g-MAH/Nano-CaCO3复合材料形态及力学性能的影响

通过改变共混物中乙烯辛烯共聚物（POE）与马来酸酐接枝POE（POE-g-MAH）的比例,研究了MAH含量对聚酰胺6（PA6）/POE/POE-g-MAH/纳米碳酸钙（nano-CaCO3）复合材料的微观结构和力学性能的影响。结果表明,MAH含量较高时,POE-g-MAH与PA6基体的相容性好,复合材料的冲击强度最高;制备工艺对复合材料的形态及力学性能有很大影响,采用两步法制备的复合材料中nano-CaCO3分散效果更好,其增容作用使弹性体分散相直径增大约100 nm,冲击强度较一步法提高21 %。     

Paint Solvent Permeation Resistance of Polyethylene,Polyethylene/Polyamide and Polyethylene/Modified Polyamide Bottles

The main objective of this study is to investigate the barrier mechanisms and properties of polyethylene, polyethylene (PE)/polyamide (PA) and polyethylene/modified polyamide (MPA) bottles against paint solvent permeation. In addition to the paint mixed solvent, the barrier properties of these bottles against the permeation of pure main solvents contained in the paint mixed solvent were investigated to understand the permeation mechanisms of the paint solvents. The paint solvent permeation resistance improves dramatically after blending PA and MPA barrier resins in PE matrices during blow‐molding. In fact, by using proper compositions, the white spirit permeation rates of PE/MPA and PE/PA bottles at 40°C are about 360 and 50 times slower than that of the PE bottle, respectively. Further investigations showed that, after blending the MPA and PA barrier resins in PE matrices, the hydrocarbon solvents present in the white spirit were nearly blocked without permeation during the permeation tests, i. e., PE/MPA bottles inhibited the permeation of hydrocarbon solvents more successfully than PE/PA bottles. In contrast, the rates of polar solvents with ketone, ether and alcohol functional groups permeating through the PE bottles are much slower than that of the white spirit and only slightly faster than those through the PE/PA and PE/MPA bottles. On the other hand, the paint mixed solvent permeation rates of PE bottles are approximately equal to the summation of permeation rates of the solvents present in mixed solvents calculated using a simple mixing rule. Somewhat surprising, the permeation rates of mixed solvents of PE/MPA bottles are dramatically faster than those calculated using a simple mixing rule, when the polar solvent contents are in a certain range.     

二元聚酰胺对丁腈橡胶／三元聚酰胺TPV结晶行为及性能的影响

研究了二元聚酰胺对丁腈橡胶／三元聚酰胺热塑性弹性体性能的影响。结果表明：二元聚酰胺对三元聚酰胺有成核剂效果；二元聚酰胺的加入可加速TPV中塑料相的结晶速率、减小其晶粒尺寸、增大结晶度，从而显著提高TPV的100％定伸应力及耐溶剂性。     

Using Nanosilica to Fine‐Tune Morphology and Properties of Polyamide 6/Poly(propylene) Blends

The effect of hydrophilic and hydrophobic nanosilica on the morphological, mechanical and thermal properties of polyamide 6 (PA) and poly(propylene) (PP) blends is investigated by extrusion compounding. Depending on the difference between the polymer/nanoparticle interfacial tensions, different morphologies are obtained as highlighted by TEM and SEM. Hydrophobic nanosilica migrates mainly at the PA/PP interface, which leads to a clear refinement of PP droplet size. The macroscopic properties of the hybrid blends are discussed and interpreted in relation with the blend morphology and melt‐mixing procedure. The control over coalescence allows a morphology refinement of the blends and improves mechanical properties.

     

振动注射对聚酰胺6晶型及力学性能的影响

对比了普通注射试样和振动注射试样晶型及力学性能的差别。研究了振动频率、振动压力对聚酰胺6力学性能和晶型的影响。结果表明,振动试样的冲击强度和拉伸强度比未振动试样有所提高;通过广角X射线衍射测试,实验结果表明振动作用会使聚酰胺6的γ晶型减少,更有利于α晶型的生成。     

Mechanical and Water Absorption Properties of Natural Fibers/Polymer Biocomposites

In the present communication a study on the preparation and characterizations of Pine Needles (PN) reinforced polymers using Phenol-Formaldehyde (PF) as a novel polymer matrix has been reported. Pine Needles (PN) of different dimensions were used to prepare biocomposites. The influence of different fiber dimension on the mechanical properties of the composites was determined. Analysis of morphological (SEM) and thermal (TGA/DTA) properties of Pine Needles, PF resin and polymer composites have also been carried out. These polymer composites were further subjected to various standardized characterization tests such as swelling under different solvents, moisture absorption and chemical resistance analysis.     

PI表面改性对PANI/PI复合膜性能的影响

采用分散聚合体系,在聚酰亚胺(PI)薄膜表面原位沉积聚苯胺(PANI)制得高导电性PANI/PI复合膜。用不同物理、化学方法对PI薄膜表面进行改性。结果表明,通过等离子体处理、超声波处理以及不同溶液浸泡处理的PI基体均改善了复合膜表面质量,提高复合膜电导率,其中过硫酸胺(APS)水溶液处理制得复合膜的电导率相对最高。紫外光谱和红外光谱分析证实基体表面为质子酸掺杂的PANI膜层,膜中不含有空间稳定剂聚乙烯吡咯烷酮。     

Flow Characteristics and Dynamic Behavior of Polyamide 6/Acrylonitile Butadiene Styrene (PA6/ABS) Blends

The objective of this research was to investigate the effect of incorporation of maleic anhydride grafted acrylonitrile-butadiene-styrene (ABS-g-MAH) on rheological properties of PA6/ABS blends. Flow properties of the blends were examined by dynamic and capillary rheometers. The dynamic rheological analyses showed an increase in complex viscosity with the incorporation of a compatibilizer. The reduction of tan δ peaks showed enhanced interfacial interaction between PA6 and ABS phase, which resulted in the enhancement of melt strength. The power law index analysis showed that 1.5 wt.% resulted in minimum n and maximum K value for the blends while still retaining the pseudoplastics behavior necessary for plastics processing and prediction for the end use performance of the PA6/ABS blends.     

聚酰胺66高取向度纤维的性能和应用

新型高取向低收缩聚酰胺66纤维具有高取向度、低热收缩率、高耐热性能和较好的耐疲劳性能,因此受到轮胎行业高端用户的青睐。介绍了高取向低收缩聚酰胺66纤维的应用前景,认为其作为骨架材料不仅满足了轮胎轻量化、增强安全性等绿色用途,同时用于缆绳、输送带和吊装带也提高了安全性能。     

Polyamide Nanocomposites: Investigation of Mechanical,Thermal and Morphological Characteristics

In the present work, polyamide/CaSO₄ nanocomposites were prepared via melt intercalation on twin-screw extruder. Different particle sizes (23, 15, 10 nm) of CaSO₄ were synthesized by in situ deposition technique and its sizes and shape were confirmed on a transmission electron microscope (TEM). The TEM study showed that nano-CaSO₄ has a needlelike or fiberlike structure. Nano-CaSO₄ was added from 1 to 4 wt% in the polyamide. Properties such as Tensile strength, Elongation at Break, Young's Modulus, and hardness were studied. These results were then compared with commercial CaSO₄-filled polyamide composites. There was a propounding effect to be observed on properties of polyamide nanocomposites due to uniform dispersion of nano-CaSO₄ and commercial CaSO₄. The 4 wt% of 10 nm CaSO₄ shows 16% improvement in Tensile Strength compared to commercial CaSO₄ (11%) filled in polyamide composites, whereas, Elongation at Break decreases drastically in 10 nm CaSO₄-filled polyamide nanocomposites up to 22% compared to commercial CaSO₄-filled polyamide composites at 4 wt% loading (11%). Among these properties, Young's Modulus was found to be more effective in 4 wt% loading of 10 nm CaSO₄ and was recorded to be 66% more compared to commercial CaSO₄-filled-in polyamide composites (22%). Moreover, thermal properties such as thermal degradation and flammability were studied by TGA and flame testers. It was found that nano-CaSO₄ was thermally more stable compared to commercial CaSO₄-filled polyamide composites. Extent of dispersion of nano-CaSO₄ was studied along with micro cracks generated during tensile testing using an Atomic Force Microscope (AFM).     

共聚PA6/66在PA66/GF复合材料中的应用

以共聚尼龙(PA)6/66和POE-g-MAH作为增韧剂,采用熔融共混法对PA66/玻璃纤维(GF)复合材料进行增韧改性,考察两种增韧剂用量对其结晶行为、力学性能、热变形温度(HDT)和熔体流动速率(MFR)的影响。结果表明,高用量的POE-g-MAH对复合材料中PA66的结晶有一定阻碍作用,而共聚PA6/66对PA66的结晶性能影响较小;随着共聚PA6/66和POE-g-MAH用量的提高,PA66/GF复合材料的冲击强度明显提高,拉伸强度、弯曲强度和HDT则逐渐下降;与POE-g-MAH相比,共聚PA6/66对拉伸及弯曲强度和HDT的不利影响较小,且略微提高了复合材料的MFR,而POE-g-MAH大幅降低了复合材料的MFR。当两种增韧剂的质量分数均为12%时,共聚PA6/66和POE-g-MAH增韧的复合材料的无缺口冲击强度和缺口冲击强度基本相当,但前者在拉伸强度、弯曲强度、HDT和MFR方面均有更明显的优势。