Biodegradable PLA foams are in great demand in many fields such as packaging and construction. However, foaming ability of PLA is confined by its poor melt viscoelasticity. To address this problem, a naturally formed nanofiller, halloysite nanotubes (HNTs) were added. By adding HNTs, foaming window of PLA was successfully extended. The compressive performance and thermal conductivities of the obtained foams were investigated. It could be seen that the PLA/HNTs composite foam with an expansion ratio of 19.2 folds exhibited the lowest thermal conductivity 34.29 mW/(m·K). The compressive modulus increased from 3.6 to 11.8 MPa with the increase of mass fraction of HNTs from 0 to 5 wt%. To further improve the compressive performance of foams, an annealing process was conducted. After annealing, compressive modulus of pure PLA foam almost doubled because of the increased crystallinity. Vicat softening temperature of annealed foams also increased by about 5 °C.

可生物降解的 PLA 泡沫在包装和建筑等许多领域都有很大的需求。然而，PLA的发泡能力受限于其较差的熔体粘弹性。为了解决这个问题，添加了自然形成的纳米填料埃洛石纳米管 (HNT)。通过添加HNTs，成功延长了PLA的发泡窗口。研究了所得泡沫的压缩性能和热导率。可以看出，膨胀率为 19.2 倍的 PLA/HNTs 复合泡沫的导热系数最低，为 34.29 mW/(m·K)。随着HNTs的质量分数从0wt%增加到5wt%，压缩模量从3.6 MPa增加到11.8 MPa。为了进一步提高泡沫的压缩性能，进行了退火过程。退火后，由于结晶度增加，纯 PLA 泡沫的压缩模量几乎翻了一番。退火泡沫的维卡软化温度也增加了约 5°C。