Siebert Stefan, Berghaus Johannes, Seide Gunnar
Aachen-Maastricht Institute for Biobased Materials (AMIBM), Faculty of Science and Engineering, Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167RD Geleen, The Netherlands.
Polymers (Basel). 2022 Mar 29;14(7):1395. doi: 10.3390/polym14071395.
The nucleating agent ,'-bis(2-hydroxyethyl)-terephthalamide (BHET) has promising effects on poly(l-lactide) (PLA) under quiescent conditions and for injection molding applications, but its suitability for industrial-scale fiber melt spinning is unclear. We therefore determined the effects of 1% and 2% (/) BHET on the crystallinity, tenacity, and elongation at break of PLA fibers compared to pure PLA and PLA plus talc as a reference nucleating agent. Fibers were spun at take-up velocities of 800, 1400 and 2000 m/min and at drawing at ratios of 1.1-4.0, reaching a final winding speed of 3600 m/min. The fibers were analyzed by differential scanning calorimetry, wide-angle X-ray diffraction, gel permeation chromatography and tensile testing. Statistical analysis of variance was used to determine the combined effects of the spin-line parameters on the material properties. We found that the fiber draw ratio and take-up velocity were the most important factors affecting tenacity and elongation, but the addition of BHET reduced the mechanical performance of the fibers. The self-organizing properties of BHET were not expressed due to the rapid quenching of the fibers, leading to the formation of α'-crystals. Understanding the behavior of BHET in the PLA matrix provides information on the performance of nucleation agents during high-speed processing that will allow processing improvements in the future.
成核剂双（2-羟乙基）对苯二甲酰胺（BHET）在静态条件下以及注射成型应用中对聚（L-丙交酯）（PLA）具有良好的效果，但其对工业规模纤维熔融纺丝的适用性尚不清楚。因此，我们测定了1%和2%（质量分数）的BHET与纯PLA以及添加滑石粉作为参考成核剂的PLA相比，对PLA纤维的结晶度、强度和断裂伸长率的影响。纤维在800、1400和2000 m/min的卷取速度下纺丝，并在1.1 - 4.0的拉伸比下拉伸，最终卷绕速度达到3600 m/min。通过差示扫描量热法、广角X射线衍射、凝胶渗透色谱法和拉伸试验对纤维进行分析。采用方差统计分析来确定纺丝线上的参数对材料性能的综合影响。我们发现纤维拉伸比和卷取速度是影响强度和伸长率的最重要因素，但添加BHET会降低纤维的机械性能。由于纤维的快速淬火，BHET的自组织性能未得到体现，导致形成α'-晶体。了解BHET在PLA基体中的行为，可为高速加工过程中成核剂的性能提供信息，从而有助于未来加工工艺的改进。
