Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan, Shandong 250061, China.
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan, Shandong 250061, China.
Int J Biol Macromol. 2019 Oct 1;138:144-155. doi: 10.1016/j.ijbiomac.2019.07.071. Epub 2019 Jul 12.
Environmental friendly and non-toxic polylactic acid (PLA) foam exhibits a promising perspective in many areas. However, PLA shows very poor foaming ability. Herein, silane-modified glass fiber (GF) was compounded with PLA to improve its foaming ability. Thanks to the increased melt viscoelasticity and melt strength, and the enhanced crystallization by adding GF, PLA/GF composites show dramatically improved foaming ability, characterized by widened processing window, increased expansion ratio, and improved cellular uniformity. Compared with pure PLA foam, PLA/GF composite foam shows dramatically enhanced mechanical properties in compressive strength and modulus. For foams with the same expansion ratio of 20-fold, the incorporation of 10 wt% GF led to increased compressive strength and modulus by 44.8% and 92.0%, respectively. The PLA/GF composite foam with an expansion ratio of 24.2-fold has a low thermal conductivity of 31.4 mW/m·K, which is comparable with the excellent thermal insulation performance of commercial polymer foams.
环保无毒的聚乳酸（PLA）泡沫在许多领域都具有广阔的应用前景。然而，PLA 的发泡能力很差。本文通过将硅烷改性玻璃纤维（GF）与 PLA 复合，来提高 PLA 的发泡能力。由于加入 GF 提高了熔体的粘弹性和熔体强度，并增强了结晶，PLA/GF 复合材料表现出了显著改善的发泡能力，其加工窗口变宽，膨胀比增大，泡孔均匀性提高。与纯 PLA 泡沫相比，PLA/GF 复合泡沫在抗压强度和模量方面表现出了显著增强的机械性能。对于膨胀比相同的泡沫，加入 10wt% GF 可使抗压强度和模量分别提高 44.8%和 92.0%。膨胀比为 24.2 倍的 PLA/GF 复合泡沫的导热系数低至 31.4mW/m·K，与商用聚合物泡沫优异的隔热性能相当。
