纺织学报 ›› 2026, Vol. 47 ›› Issue (05): 81-90.doi: 10.13475/j.fzxb.20250900201

• 纤维材料 • 上一篇    下一篇

聚酰胺66中低聚物的超高效液相色谱法测定

莫海玲1,2, 刘可1,2, 戴钧明2, 吕汪洋1,2()   

  1. 1 浙江理工大学 生物基纤维材料全国重点实验室, 浙江 杭州 310018
    2 浙江省现代纺织技术创新中心, 浙江 绍兴 312000
  • 收稿日期:2025-09-01 修回日期:2026-03-11 出版日期:2026-05-15 发布日期:2026-07-10
  • 通讯作者: 吕汪洋(1982—),男,教授,博士。主要研究方向为纤维材料绿色制备技术。E-mail:luwy@zstu.edu.cn。
  • 作者简介:莫海玲(2001—),女,硕士生。主要研究方向为聚酰胺低聚物。
  • 基金资助:
    浙江省“尖兵领雁+X”研发攻关计划项目(2024SJCZX0023)

Determination of oligomers in polyamide 66 by ultra-high performance liquid chromatography

MO Hailing1,2, LIU Ke1,2, DAI Junming2, LÜ Wangyang1,2()   

  1. 1 State Key Laboratory of Bio-based Fiber Materials, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
    2 Zhejiang Provincial Innovation Center of Advanced Textile Technology, Shaoxing, Zhejiang 312030, China
  • Received:2025-09-01 Revised:2026-03-11 Published:2026-05-15 Online:2026-07-10

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摘要：

聚酰胺66(PA66)材料中的低聚物是其聚合过程产生的副产物,其组成与含量对材料的加工与应用性能具有潜在影响。为探究PA66中低聚物的组成与含量,建立了一种基于溶解-沉淀法的提取、分离与检测方法。首先采用溶解-沉淀法从PA66切片中提取低聚物,利用Prep 150型制备液相色谱对其进行高效分离。在此基础上,借助液相色谱-飞行时间质谱联用仪(LC-TOF-MS)对一聚体~六聚体(C1~C6)进行定性鉴定,为其定量分析提供准确的定性基础。随后,基于经制备液相色谱纯化所得的低聚物标准品,建立了超高效液相色谱(UPLC)定量分析方法,可准确测定一聚体~五聚体(C1~C5)的含量。实验结果表明,该方法的定量范围较宽,线性良好(决定系数R2>0.99),且具有分析时间短(单次检测时间<12 min)、重复性高(相对标准偏差<3%)等优点。方法操作简便、结果可靠,可为PA66生产过程中低聚物的质量控制提供有效的分析手段,对优化其聚合工艺具有指导意义。

关键词: 聚酰胺66, 低聚物, 超高效液相色谱, 溶解-沉淀法, 定量分析, 液相色谱-飞行时间质谱

Abstract:

Objective As the influence of oligomers on material properties remains insufficiently understood, their accurate quantification is crucial for evaluating performance, optimizing polymerization, and enhancing quality control. The objective of this study is to develop a reliable analytical method for identifying and quantifying oligomers (C1-C5) in polyamide 66 (PA66). This method provides essential data for process monitoring and helps elucidate structure-property relationships, thereby supporting improved product consistency and advanced manufacturing standards in the polyamide industry.

Method Oligomers were extracted from PA66 using a dissolution-precipitation method. Separation was achieved by preparative liquid chromatography (Prep-LC), followed by qualitative analysis using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS). Quantitative determination of C1-C5 oligomers was performed using ultra-high performance liquid chromatography (UPLC) with purified oligomer standards.

Results A highly efficient method for extracting, separating, and quantifying PA66 oligomers was successfully established. Low-molecular-weight oligomers were effectively extracted from PA66 chips using a dissolution-precipitation method. Based on LC-TOF-MS analysis with high-accuracy mass measurement (mass error < 5×10-3 u) and characteristic fragment ion patterns, cyclic and linear oligomers ranging from monomer to hexamer (C1-C6) were clearly identified. After optimizing the liquid chromatographic conditions, a rapid UPLC quantitative method was established and validated. All five target cyclic oligomers (C1-C5) exhibited excellent linearity within the concentration range of 0.008-0.1 g/L (R2 >0.99). The method demonstrated high precision and reliability, with intra-day and inter-day relative standard deviations (RSD) for peak area and retention time below 2.0% and 3.0%, respectively. The analysis time was shorter than 20 min for each sample, significantly improving throughput compared to conventional techniques. When applied to industrial PA66 chip and fiber samples, the total extractable oligomer content was measured to range from 1.2% to 1.6% by mass, with cyclic oligomers accounting for more than 90% of this fraction. The total oligomer content in fiber samples (average 1.388%) was consistently lower than that in their corresponding precursor chips (average 1.483%), indicating possible migration or further condensation of oligomers during the melt-spinning process. Detailed compositional analysis provided species-specific concentration data, revealing that the cyclic monomer and dimer were the most abundant components. The approach offers a robust solution for monitoring oligomer content, providing detailed compositional insights that are critical for evaluating polymerization efficiency and product consistency.

Conclusion This study established a UPLC-based method for the separation and quantification of PA66 oligomers, integrating preparative LC, UPLC-PDA, and LC-TOF-MS. Different from the conventional method for determining the total oligomer content, the method successfully separated and quantified five cyclic oligomers. Quantification was achieved by monitoring at 200 nm and using mixed-standard calibration curves, demonstrating high efficiency, reproducibility, and superior performance over existing methods. Applied to commercial PA66 chips and fibers, the measured oligomer ranges aligned with typical industrial levels, and the observed content differences between physical forms provide a basis for optimizing polymerization and processing formulations. The developed method enables rapid, accurate, and reproducible quantification of PA66 oligomers. It offers significant practical value for quality assurance in industrial production settings. By facilitating precise monitoring of oligomer levels, this approach supports process optimization and helps enhance the final material properties of PA66. Future applications may include monitoring and extended adaptation to other polyamide types.

Key words: polyamide 66, oligomer, ultra-high performance liquid chromatography, dissolution-precipitation method, quantitative analysis, liquid chromatography-time of flight mass spectrometry

中图分类号: 

  • TS102.5

表1

超高效液相色谱洗脱程序"

时间/min 体积分数/%
流动相A 流动相B
0 95.0 5.0
7.0 60.0 40.0
7.5 10.0 90.0
8.5 4.0 96.0
10.0 95.0 5.0
12.0 95.0 5.0

表2

制备液相色谱洗脱程序"

时间/
min		 流速/
(mL·min-1)		 体积分数/%
流动相A 流动相B
1.84 20 95.0 5.0
8.50 20 70.0 30.0
8.60 10 66.0 34.0
9.40 10 58.0 36.0
9.50 20 60.0 40.0
10.00 20 95.0 5.0

表3

PA66中低聚物的质谱参数"

名称 分子式 保留时间/min 理论质荷比 实际质荷比 加合离子类型 绝对质量误差/u
C1 C12H22N2O2 4.06 249.165 7 249.163 7 [M+Na]+ 2.0×10-3
L2 C24H46N4O5 4.36 471.354 6 471.357 2 [M+H]+ -2.6×10-3
C2 (C12H22N2O2)2 5.67 475.326 0 475.326 0 [M+Na]+ 0.0×10-3
L3 C36H68N6O7 5.27 697.522 8 697.527 3 [M+H]+ -4.5×10-3
C3 (C12H22N2O2)3 6.41 701.494 2 701.494 4 [M+Na]+ -0.2×10-3
L4 C48H90N8O9 5.89 923.690 9 923.689 1 [M+H]+ -1.8×10-3
C4 (C12H22N2O2)4 6.81 927.662 3 927.664 0 [M+Na]+ -1.7×10-3
L5 C60H112N10O11 6.30 1 149.859 0 1 149.862 9 [M+2H]2+ -3.9×10-3
C5 (C12H22N2O2)5 7.09 1 153.830 4 1 153.831 3 [M+2Na]2+ -0.9×10-3
L6 C72H134N12O13 6.65 1 375.019 3 1 375.018 3 [M+2H]2+ 1.0×10-3
C6 (C12H22N2O2)6 7.29 1 379.998 5 1 379.997 1 [M+2Na]2+ 1.4×10-3

图1

不同方法提取的低聚物液相色谱图"

图2

溶剂种类对PA66中低聚物含量的影响"

图3

甲酸体积对PA66低聚物提取效率的影响"

图4

进样体积对PA66低聚物含量的影响"

图5

不同波长下环状低聚物色谱图"

图6

部分PA66环状低聚物的紫外吸收光谱图"

表4

PA66各环状低聚物线性回归方程和决定系数"

低聚物组分 线性方程 决定系数(R2)
C1 y=9 502 618.92 x + 3 516.14 0.999 6
C2 y=9 184 837.75 x + 3 290.22 0.999 6
C3 y=9 091 985.62 x + 3 225.33 0.999 6
C4 y=6 846 781.39 x + 1 419.33 0.999 3
C5 y=6 079 394.52 x + 398.68 0.994 8

图7

重复进样的低聚物PDA谱图"

表5

PA66中各环状低聚物含量的平行样测试结果"

低聚物
组分		 环状低聚物含量/% 相对标准
偏差/%
试样1 试样2 试样3
C1 0.372 0.376 0.373 1.951
C2 0.483 0.486 0.488 1.249
C3 0.308 0.307 0.310 0.686
C4 0.288 0.275 0.272 0.868
C5 0.146 0.142 0.145 1.379

表6

不同样品PA66中低聚物含量测试结果"

样品 环状低聚物的含量/% 总含量/%
C1 C2 C3 C4 C5
PA66切片1 0.435 0.521 0.345 0.263 0.100 1.664
PA66切片2 0.366 0.476 0.307 0.260 0.105 1.514
PA66切片3 0.321 0.375 0.248 0.189 0.073 1.206
PA66切片4 0.344 0.410 0.274 0.209 0.085 1.323
PA66切片5 0.332 0.409 0.295 0.219 0.081 1.336
自制PA66切片 0.353 0.469 0.314 0.224 0.122 1.483
自制PA66纤维 0.304 0.445 0.298 0.232 0.108 1.388
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