降低PA6切片中可萃取物含量的工艺研究

通过研究切片的质量、萃取水的温度及浴比对聚己内酰胺切片中可萃取物含量的影响。探讨了己内酰胺的聚合过程中的萃取工艺，为提高切片质量，降低能耗和物耗提供可行的经验。     

聚己内酰胺切片萃取水回用直接聚合工艺探讨

己内酰胺聚合装置回收萃取水中的己内酰胺采用“三效蒸发”、“真空蒸馏”的方法 ,回收率只有 60 %。改用高压前聚、常压后聚的工艺 ,将 85 %浓缩液按 10 %的比例与己内酰胺混合加入 ,前聚压力0 .3MPa以上 ,温度 2 60℃ ,回收率可以达到 90 %以上 ,己内酰胺单耗下降到 10 10 kg/t,聚合时间从 2 3h缩短到 18h     

己内酰胺聚合装置萃取蒸发系统节能改造技术经济分析

以60kt/a己内酰胺聚合装置萃取蒸发系统为例,探讨了影响萃取蒸发系统蒸汽消耗的因素,分析了装置节能改造的方案和效果.结果表明:影响己内酰胺聚合装置萃取蒸发系统蒸汽消耗的因素包括萃取水量、萃取水温度、蒸发回流量、蒸发浓缩液固含量;采用三效蒸发+浓缩液闪蒸技术对60 kt/a己内酰胺聚合装置进行改造,同时控制萃取水浴比为...     

聚醚改性铸型尼龙的研究

介绍了聚醚改性铸型尼龙的制备方法，以聚醚和异氰酸酯为原料合成预聚体活化剂在该活化剂存在下引发己内酰胺阴离子聚合，聚体韧性被显著改善。讨论了各各绎制备过程的影响，并测试了制品性能与预聚体用量的关系，当预体用量为聚合体重的８％时，材料缺口冲击强度最高。     

尼龙6连续聚合过程的流程模拟与调控

基于流程模拟软件Aspen Polymer Plus建立了己内酰胺水解聚合生产尼龙6的两段式工艺过程模型,利用该模型对某厂2万吨/年两段式生产工艺进行模拟,各聚合阶段内己内酰胺、环状二聚体含量、聚合物分子量,以及各聚合阶段温度分布和两聚合塔塔顶出水量等结果均与工业值吻合良好,模型可靠。在此基础上,进一步模拟考察了聚合反应过程中进料水含量、分子量调节剂含量、各聚合阶段温度和各聚合塔压力等因素对己内酰胺转化率、环状二聚体生成以及聚合产品分子量的影响,并进行了参数灵敏性分析。结果表明:较低的进料水含量、降低反应温度和前聚塔压力及提高后聚塔的真空度均有利于降低聚合产品中环状二聚体的含量;两个聚合塔下半段的温度变化对环状二聚体产生有显著影响,提高后聚塔真空度可显著提高聚合物分子量。以尼龙6连续聚合过程的环状二聚体含量调控为目标,在优化的操作条件下,尼龙6聚合物中环状二聚体的含量可降低约16%。     

降低聚己内酰胺可萃取物含量研究进展

介绍了国外低可萃取物含量的聚合技术及高效萃取技术研究进展,具有代表性的聚合技术有低温聚合、催化聚合、低聚物裂解再聚合技术、浓缩液超比率再加料聚合技术提出通过改进聚合萃取生产工艺,可以开发出低成本高质量的聚己内酰胺     

聚己内酰胺生产中被氧化原因及预防措施

影响聚己内酰胺氧化的因素主要是氧含量、反应温度、反应时间、重金属盐及端氨基含量等,防止聚己内酰胺在生产中被氧化的措施主要是优化生产工艺参数,优选设备材质及原料等。     

己内酰胺聚合管V型挡板的研制

在己内酰胺直型聚合管设计中采用了 V型挡板 ,经模拟试验和实际应用 ,效果均十分明显。采用 V型挡板改善聚己内酰胺熔体的径向混合效果 ,有效地减少己内酰胺熔体的径向温差 ,确保聚合物相对分子质量的稳定     

基于尼龙6生产过程的聚合反应模拟优化

采用Aspen Plus模拟软件对己内酰胺水解聚合生产尼龙6工业过程进行模拟分析与优化,建立了尼龙6水解聚合生产工艺流程模型,考察了进料水含量,反应温度、前聚合管反应器压力、后聚合管反应器的真空度等影响低聚物生成的影响因素。模拟结果表明,通过降低生产工艺的反应温度、减少进料水含量、提高聚合管反应器的真空度以及降低反应器压力等方式均能有效降低聚合产品中环状聚物的含量。通过减少聚合反应过程中低聚物生成,提出了尼龙6工业生产过程中控制环状低聚物生成的工艺路线。     

聚酰胺6—聚醚嵌段共聚物增韧改性

以聚四氢呋喃醚为软段制备大分子活化剂，引发己内酰胺阴离子聚合，合成了聚酰胺６－聚醚嵌段共聚物，并考察大分子活化剂种类、用量对聚合物力学性能的影响。结果表明，所得制品在保持一定强度、硬度的条件下，冲击性能可大幅度提高，取的了较好的增韧效果。     

Characteristics of polymerization-filled polycaprolactams

A polymerization filling of a base in character monomer (ϵ-caprolactam) was carried out using fillers with solid acid character and catalytic action such as γ-alumina and calcium phosphate. The properties and structure of the polymerization-filled polycaprolactam obtained were studied. The following characteristics were determined: melting temperature, glass transition temperature, crystallization temperature, tensile strength, and dynamic elastic modulus. The advantages of the polymerization filling method are shown as compared to conventional methods for homogeneous production of polycaprolactam. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1255–1258, 1997     

Study on the polymerization of ϵ‐caprolactam in the interlamellar spaces of [TEACOOH]–montmorillonite intercalations complex and its characterization

The polymerization of ?‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ?‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003     

银离子抗菌聚己内酰胺纤维的研制及开发

主要介绍银离子抗菌聚己内酰胺纤维的制造方法、设备、原料及纺丝工艺。如抗菌母粒的选择,纺丝温度,纺丝组件,纺丝油剂及上油率,卷绕速度。采用高速纺丝法工艺路线成功开发出银离子抗菌聚酰胺纤维。     

Crosslinking reaction of epoxy resin (diglycidyl ether of bisphenol A) by anionically polymerized polycaprolactam: I. Mechanism and optimization

Different ratios of epoxy resin, diglycidyl ether of bisphenol A (DGEBA) and ?‐caprolactam (starting from 10:90 DGEBA and vice versa), were used to synthesize reactive DGEBA and polycaprolactam blends by the anionic polymerization of ?‐caprolactam at 140°C. Anionic polymerization was conducted with a strong base such as sodium hydride as a catalyst along with a cocatalyst such as N‐acetyl caprolactam. The reaction mechanism, possible cure reactions, and reaction conditions of the reactive blends were studied with Fourier transform infrared spectroscopy and differential scanning calorimetry. The experiments were carried to study the optimization ratio and the effect of the composition on properties such as hardness and tensile strength of the reactive blends. The DGEBA was crosslinked by polycaprolactam through the reaction of the oxirane group with the amide nitrogen, and the reaction was very fast. A ratio of 80:20 (DGEBA:?‐caprolactam) was optimum, and the resulting blend showed the highest tensile strength and hardness. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3237–3247, 2003     

Photochemical grafting of acrylated azo dyes onto polymeric surfaces. V. Grafting of some acryloxy-substituted aromatic diazenes as model molecules onto polypropylene,polycaprolactam, and poly(ethylene terephthalate) films

Photochemically induced grafting (1) and graft polymerization (2) from N,N-dimethylformamide solutions of four acryloxy-substituted aromatic diazenes, chosen as model molecules of acryloxy azo dyes, were investigated kinetically at 25°C onto polypropylene, polycaprolactam, and poly(ethylene terephtalate) films, by polychromatic irradiations. Quantum efficiencies at zero concentration of dyes and lifetimes of excited states for processes (1) and (2) were evaluated from experimental data by Stern–Volmer plots. The surface density of grafted molecules at the end of process (1) was not affected by the concentration of dyes in solution, but varied sensibly with the chemical nature of polymers and dyes. The relevant parameters are discussed on the basis of the proposed mechanism.     

Molecular weight distribution of polycaprolactam,anionically synthesized in presence of lithium chloride

Samples of polycaprolactam, obtained by anionic polymerization of caprolactam in bulk under adiabatic conditions and in presence of different amounts of lithium chloride, have been fractionated using a method based on summative fractionation of the polyamide in the amorphous state. By increasing the amount of lithium chloride in the system, the limiting viscosity number of the as-polymerized material decreases; at the same time the integral distribution curves reveal a bimodal molecular weight distribution as a consequence of the complex pattern of main and side reactions. The high molecular weight peak is very narrow, both with and without lithium chloride in the polymerizing system. Lithium chloride considerably reduces the polydispersity of the low molecular weight portion, which is very broad for the non-salt treated polycaprolactam. The relative importance of the two peaks, which is almost even for polycaprolactam synthesized without salt, is shifted in favour of the lower molecular weight peak by increasing the salt content. This effect is also accompanied by a higher production of water-soluble oligomers.     

Optimization of spinning,drawing, and annealing conditions in the production of highly oriented fibers from the polycaprolactam/3.7% LiCl system

A polycaprolactam/3.7% w/w LiCl system, obtained by anionic polymerization of caprolactam directly in the presence of salt, has been employed for the production of highly oriented fibers. More particularly, an optimization of spinning, drawing, and annealing conditions has been performed, finally obtaining fibers which shows very satisfactory mechanical results. Namely, average moduli values up to 12 GPa and strength values up to 1 GPa when fracture is far from clamps, have been observed.     

聚己内酰胺切片的热学及流变性能研究

借助热分析技术和毛细管流变仪,分别对两种全消光聚己内酰胺纺丝切片的热学性能和流变性能进行了研究和分析,旨在为熔融纺丝生产工艺控制提供一定的理论依据。结果表明:两种切片在纺丝温度范围内热降解程度均可满足正常纺丝,A公司的切片较易发生结晶;剪切速率越大,熔体受温度的影响越小,稳定性越好;在相同剪切速率下,A切片的黏流活化能较B切片的高,表观黏度对温度的依赖性大。