Polylactide single-polymer composites with a wide melt-processing window based on core-sheath PLA fibers

Publication date: 5 February 2018
Source:Materials & Design, Volume 139
Author(s): Qingsheng Liu, Mingming Zhao, Yuqi Zhou, Qibing Yang, Ying Shen, R. Hugh Gong, Fenglei Zhou, Yuhao Li, Bingyao Deng
Polylactide (PLA) single polymer composites (SPCs) were prepared using PLA nonwovens made of core-sheath PLA fibers as raw materials by hot-pressing. The core and sheath materials were poly(l-lactide) (PLLA) and PLA with d-lactide of about 10mol% (PLA90), respectively. The melt processing window of PLA SPCs reached more than 40°C. The effects of hot-pressing temperature on the crystallinity, the size distribution of crystallites, the lamellar thickness and mechanical property of PLA SPCs were significant while those of hot-pressing pressure were small. The strong interfacial adhesion between matrix and reinforcement led to high mechanical properties of PLA SPCs. For pure PLA materials prepared at 180°C, the tensile strength (σb), elongation at break (εb), the work of rupture (W) and impact strength (αcU) were only 19MPa, 1.8%, 0.15J, and 2.8kJ/m², respectively while those of the SPCs prepared at 130–160°C were 47–65MPa, 15–32%, 9–22J, and 14.9–67.2kJ/m², respectively. With the increase of hot-pressing temperature, the σb, W and αcU decreased.

Graphical abstract

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