Nylon 4/PVA blend membrane for dialysis

To improve the hydrophilicity and enhance the transport flux of nylon 4 membrane for dialysis, this study attempts to utilize blending nylon 4 with poly(vinyl alcohol) (PVA). The instability of PVA in water can be obtained more easily than by other methods, such as chemical, γ-ray irradiated crosslinking, or high-temperature treatment used by previous researchers. The effects of maturation time of the casting solution, nylon 4/PVA ratios, and casting solvent compositions on esterification of PVA, salt permeability, water content, partition coefficient, diffusivity, and mechanical strength of membrances are studied. The membrane, prepared by casting solution of nylon 4/PVA = 9/1 wt % formic acid with 24-h maturation time, possesses permeabilities of NaCl and urea, 33.14 and 19.67 × 10^?5 cm²/min, respectively.     

Plasma-modified Nylon 4 membrane for dialysis

The effects of plasma treatment conditions, such as supply power, treatment time, gases used in reactor, surface energy, water content, dialysis permeability, partition coefficient, diffusion coefficient, and free volume of Nylon 4 membranes, were studied. The solutes considered for dialysis system were NaCl, urea, and MgCl₂. The permeabilities of NaCl and urea of membranes with plasma treated in argon at 80 W for 20 min are 5.57 × 10^?5 and 5.89 × 10^?5 cm²/min, respectively. Much higher permeabilities of NaCl and urea obtained by oxygen plasma-treated membranes under 20 W and for 20 min are 30.74 × 10^?5 and 17.66 10^?5 cm²/min, respectively, compared to that of untreated Nylon 4 membranes.     

Photolithographically patternable modified poly(HEMA) hydrogel membrane

Summary Polymer with pendant methacryloyl group was synthesized by the substitution reaction of poly(2-hydroxyethyl methacrylate) [poly(HEMA)] with methacryloyl chloride. This photocurable polymer was characterized using ¹H-NMR and bromine titration, and the results were reasonably well consistent. The photocrosslinking of this modified poly(HEMA) was carried out by the addition of a low molecular weight sensitizer without adding functional monomer and crosslinker. These precursors showed a high photosensitivity. Polymers with a degree of substitution as low as 2 mol-% methacryloyl group could be efficiently crosslinked within few seconds of UV exposure to give water insoluble transparent hydrogel membranes. By irradiation of a film of the photocurable polymer precursor containing lacatate oxidase (LOD), a rather unstable enzyme, the enzyme was gently immobilized by physical entrapment.     

MC尼龙／纳米CaSO4复合材料的制备与表征

采用原位聚合反应制备MC尼龙／纳米CaSO4复合材料并对其性能、形貌和结晶形态进行了分析。分析结果表明：复合材料中纳米CaSO4达到了纳米级分散,起到同时增强增韧的作用,复合材料拉伸强度比MC尼龙提高17．4％;弯曲模量提高26．9％;冲击强度提高16．7％。纳米CaSO4的引入没有改变尼龙6的结晶形态;修饰后的纳米CaSO4有利于在MC尼龙中均匀分散。     

蒙脱土插层尼龙66及其合金力学性能研究

先采用有机化蒙脱土(org MMT)插层尼龙66制得了PA66/PP纳米复合材料,对其力学性能进行了测试。试验结果表明:MMT含量为7%时,PA66/MMT的各项性能达到最优,但是材料的韧性仍较差,进而采用与聚丙烯共混改性的方法增韧制得PA66/PP/MMT纳米复合材料,当MMT含量为5%,PA66∶PP为80∶20时,材料的冲击强度提高45 4%,而其他各项性能基本保持不变。     

Photopolymerization of HEMA/DEGDMA hydrogels in solution

Photopolymerization is a widely used technique to synthesize polymers and hydrogels. The commonly used ultraviolet (UV)-curable mono-, di- or multifunctional vinylated monomers are often volatile, causing difficulty in kinetics analysis such as photo-differential scanning calorimetry (PhotoDSC). In this work, the DSC sample pan is chemically and physically modified such that the resin can be placed uniformly in the sample pan with minimum sample weight loss during measurement. This approach substantially improved experimental accuracy, which in turn provides a better understanding of the reaction kinetics of UV-curable polymers. Kinetic experiments were carried out for poly(2-hydroxyethyl methacrylate) (HEMA)-based hydrogels. The effects of light intensity and water concentration on the reaction kinetics and rheological change was investigated. It was found that increasing the light intensity enhances the polymerization, but too high an intensity slows down the reaction at the later stage. The addition of solvent and high light intensity facilitates the cyclization, delaying macrogelation. The viscosity rise of the resin system and the formed polymer size were also measured using a photorheometer and a particle size analyzer, respectively. The measured gel time, gel conversion and polymer size distribution agree with the kinetic analysis.     

单分散多孔聚MMA/HEMA微球的制备

采用液滴微流控法,制备了单分散性良好的水包油(O/W)乳液,以此乳液为模板,通过紫外光引发聚合得到单分散多孔聚甲基丙烯酸甲酯(MMA)/甲基丙烯酸2-羟乙酯(HEMA)多孔微球。研究了油相中表面活性剂聚蓖麻酸甘油酯(PGPR)含量对微球表观密度孔隙率及对乙二醇二甲基丙烯酸酯(EGDMA)的吸附能力的影响。结果表明:增加PGPR含量可改变微球的多孔结构并增大其吸附能力,在油污废水处理领域具有潜在的应用价值。     

Nylon 4,I: an amorphous polyamide

The melt polymerization of nylon 4, I was studied, starting with nylon-salt and nylon prepolymers (η_inh=0.25). With nylon-salt only low molecular polymers were obtained, while with prepolymers the inherent viscosity could be raised to 0.77 (3h, 270°, vac.). The cyclization of tetra methylene diamine to pyrrolidine seem to be the major disturbing factor. The polymer is glassy and could easily be melt pressed. The torsion modulus of the material at 20°C was high (1.8 10⁹ Pa) and remained high to near its T_g (138°C).     

蛭石/PA46复合成核剂对PA66性能的影响

通过熔融共混法制备了尼龙(PA)66/蛭石/PA46复合材料,透射电镜(TEM)观察表明,蛭石以纳米尺寸均匀分散于PA66基体中.用差示扫描量热(DSC)分析仪和正交偏光显微镜(PLM)研究了复合材料的结晶行为和结晶形态,结果表明,蛭石/PA46是PA66有效的复合成核剂,其可使PA66的结晶温度升高约20℃,非等温结晶峰半高宽和过冷度均为原来的50％左右,半结晶时间缩短,结晶速率大幅提高,并使PA66的球晶尺寸明显细化和均匀.力学性能测试表明,PA66/蛭石/PA46复合材料的强度和韧性均得到改善.蛭石/PA46的加入缩短了PA66的注射成型周期,复合材料的注射成型速率比纯PA66提高了30％.流变行为研究表明,蛭石/PA46使PA66在高剪切速率下的黏度下降较快,非牛顿指数降低,黏流活化能降低,使PA66对温度的敏感性降低.     

Nylon 6/Na-montmorillonite nanocomposites prepared by compounding Nylon 6 with Na-montmorillonite slurry

We report a novel compounding process using Na-montmorillonite water slurry for preparing novel nylon 6/Na-montmorillonite nanocomposites. In this compounding process, the Na-montmorillonite slurry was blended with melting nylon 6 using an extruder, followed by removing the water. The Na-montmorillonite silicate layers were found to be exfoliated and dispersed homogeneously at nanometer level in the nanocomposites with an electron transmission microscope. The exfoliated Na-montmorillonite silicate layers were fixed in the nylon 6 matrix almost as they were in water. The nylon 6/Na-montmorillonite nanocomposites, loaded with only 1.6 wt% clay silicate layers, exhibited high strength, high modulus, high heat distortion temperature and low gas permeability compared to neat nylon 6. The properties of the nylon 6/Na-montmorillonite nanocomposites were nearly equal to those of conventional nylon 6/clay nanocomposites prepared by dry-compounding nylon 6 and organophilic clay ion-exchanged with alkylammonium ions.     

NVP-HEMA-AM三元共聚物水凝胶对氯霉素的缓释作用

采用本体共聚法制备了丙烯酰胺(AM)与甲基丙烯酸-2羟-基乙酯(HEMA)以及N-乙烯基吡咯烷酮(NVP)共聚物水凝胶,研究了AM-HEMA-NVP共聚物水凝胶对广谱抗菌药物氯霉素的缓释作用。结果表明,随氯霉素溶液浓度增大、NaC l浓度降低、温度升高以及NVP或者AM组分的含量增大,AM-HE-MA-NVP三元共聚物水凝胶对氯霉素的吸收量增大;随AM-HEMA-NVP三元共聚物水凝胶中NVP或者AM组分含量的增大,氯霉素的释放速度明显增大;氯霉素从水凝胶中缓释的动力学可采用Fick扩散动力学描述,其释放过程受水凝胶溶胀过程以及氯霉素扩散过程控制。     

聚烯烃/尼龙合金材料的性能

为了改善尼龙6的综合性能,采用聚烯烃与其复合,制得高分子合金材料,对复合材料的结构和性能进行分析.结果表明:聚烯烃和尼龙6在相容剂的作用下可以较好地复合,并有效地降低了PA6的吸湿性,提高制品的尺寸稳定性;随着相容剂用量的增加,合金体系的拉伸强度、断裂伸长率都有所提高;PA6的低抗冲击性、低温韧性也得到有效的改善.     

短切碳纤维增强尼龙66复合材料研究进展

碳纤维的表面处理和尼龙的改性以及各种碳纤维/尼龙基复合材料的制备是当前研究热点之一。与纯尼龙相比,碳纤维的加入使材料表现出更优异的力学和摩擦学性能,拓展了尼龙高技术领域的应用空间。概述了碳纤维/尼龙66复合材料的制备方法、结构及性能方面研究进展,并提出了相关研究方向,为今后提高碳纤维增强尼龙66基复合材料力学性能和摩擦学性能研究提供参考。     

尼龙66/1010/1212热熔胶的研制

采用尼龙66/1010/1212共聚工艺,从配方上改进了单体残留问题,同时,根据单体含量-熔点曲线,探索了尼龙66/1010/1212的熔点与配比关系的实验方法。     

Antimicrobial P(HEMA/IA)/PVP semi-interpenetrating network hydrogels

New semi-interpenetrating networks (semi-IPNHs) (P(HEMA/IA)/PVP) were prepared by free radical crosslinking copolymerization of 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA, 5 mol%), in the presence of poly(vinyl pyrrolidone) (PVP, 2, 5, and 10 mol%), as an interpenetrating agent. The structure of the semi-IPNHs was confirmed by Fourier transform infrared spectroscopy, and morphology study was performed by scanning electron microscopy, which revealed the characteristic porous morphology. The results obtained by dynamic mechanical analysis showed the improvement of mechanical properties with increasing PVP content in semi-IPNs. The maximum swelling was observed for all studied systems at a slightly acidic media (around pH 6), so it can be said that the content of PVP has no influence on the swelling behavior, in the PVP range investigated. Along with the pH sensitivity, which was expected due to the presence of IA, semi-IPNHs showed temperature-sensitive swelling properties, with the lower critical solution temperature value around 41 °C, which is in the physiologically interesting interval. The antimicrobial activity of the samples was tested using E. coli, S. aureus, and C. albicans pathogens. It was noticed that the antimicrobial potential depends on type of microbes, time of exposure, and PVP content in the samples. Due to their good antimicrobial and mechanical properties these stimuli-sensitive semi-IPNHs have potential to be used as biomaterials for the applications in medicine and pharmacy.     

GMA／HEMA／NVP三元共聚物的合成及性能研究

以ＥＧＭＥ为溶剂,ＡＩＢＮ为引发剂合成ＧＭＡ／ＨＥＭＡ／ＮＶＰ三元共聚物。将它涂覆在聚酯ＰＣ片上进行升温固化,测试涂层的防雾性能,并对其表面进行ＡＴＲ红光谱分析。     

尼龙6／聚丙烯共混体系研究进展

制备性能优良的尼龙 6 /聚丙烯 (PA6 /PP)共混物 ,需要解决的关键问题是PP在PA6树脂中的分散及界面相容性。近年来 ,PA6 /PP相容性研究主要是引入第三组分作共混物的增容剂。综述了PA6 /PP共混物的最新研究及发展趋势     

蒙脱土(MMT)/PA纳米复合材料的制备与性能研究

用熔融插层法制备 MMT/PA纳米复合材料 ,先合成有机改性蒙脱土 ,再将 PA6和 PA66分别与改性 MMT共混制成纳米复合材料。表征了其结构和力学性能 ,观察了 MMT/PA6和 MMT/PA66纳米复合材料的阻燃特性。发现纳米 MMT也能将 PA66的冲击强度提高近 50 % ,并能提高 PA6的 LOI,与其他阻燃剂起协同效应     

MC尼龙6／ZnO纳米复合材料制备

将铝酸酯偶联剂和纳米ZnO同时用超声分散在熔融的己内酰胺中,一步原位聚合制备MC(单体铸塑)尼龙6/ZnO纳米复合材料,应用正交试验对偶联剂的用量和超声温度、时间等工艺参数进行了优化.结果表明,当超声温度为80℃、超声时间为20 min、偶联剂加入量为1.0%(质量分数)时,合成的MC尼龙6/ZnO纳米复合材料力学性能最优.通过SEM和XRD对MC尼龙6/ZnO纳米复合材料进一步的表征表明,ZnO在基体中达到了纳米级的分散,结晶形态理想.     

马来酸酐接枝聚烯烃／尼龙共混合金的研究进展

概述了马来酸酐接枝聚烯烃同尼龙共混合金的制备方法及目前最新的研究进展。