This work is focused on the effect of the content and length of cellulose fibres on PLA foams produced by extrusion-foaming process assisted by sc-CO₂. The produced foamed samples were characterised by water pycnometry, modulated differential scanning calorimetry, and scanning electron microscopy. Increasing the length and the content of cellulose fibres results in a reduction of the expansion of the foams at a given die temperature. Nevertheless, long fibres at low content allows an increase of the longitudinal expansion of the foams. Furthermore, composite foams can be processed at a lower die temperature than neat PLA, providing a wider processing window. In general, the addition of cellulose fibres increases the crystallinity of the foams. Narrower cell size distributions and smaller cells are obtained when adding fibres, implying more homogeneous foam structures.

本工作主要研究纤维素纤维含量和长度对_{sc-CO 2}辅助挤出发泡工艺生产的PLA泡沫的影响。通过水比重测定法、调制差示扫描量热法和扫描电子显微镜对产生的泡沫样品进行了表征。增加纤维素纤维的长度和含量会导致在给定模具温度下泡沫膨胀的减少。然而，低含量的长纤维可以增加泡沫的纵向膨胀。此外，复合泡沫可以在比纯 PLA 更低的模具温度下加工，从而提供更宽的加工窗口。一般来说，纤维素纤维的添加增加了泡沫的结晶度。添加纤维时会获得更窄的泡孔尺寸分布和更小的泡孔，这意味着泡沫结构更均匀。