Effect of bubble nucleating agents derived from biochar on the foaming mechanism of poly lactic acid foams
Effect of bubble nucleating agents derived from biochar on the foaming mechanism of poly lactic acid foams
复制标题
DOI：
10.1016/j.apsadv.2021.100059
复制
发表时间：
2021-03
期刊：
影响因子：
--
通讯作者：
H. Haham;Andrew R. Riscoe;C. Frank;S. Billington
中科院分区：
文献类型：
--
作者：
H. Haham;Andrew R. Riscoe;C. Frank;S. Billington
有效聚乳酸 (PLA) 发泡的改进和新技术仍在开发中。本研究考察了生物炭 (BC) 通过超临界 CO2 批量工艺辅助 PLA 发泡的能力。为了确定合适的发泡参数，对纯 PLA 薄膜进行了工艺优化。来自三种不同来源——污泥（SLG）、开心果壳（PST）和绿色废物（GW）的BC颗粒被研磨、球磨至微米级，然后与PLA混合。 PLA/BC 共混物被挤出成薄膜，然后批量发泡。 BC 的效果被发现与浓度和来源有关。发现 0.25 wt% 的 BC 颗粒是有效的成核剂，与纯 PLA 泡沫相比，泡孔密度增加了四个数量级，平均孔径减小了 10 倍。 BC 含量增加至 0.5 和 1 wt% 会引起颗粒聚集，从而导致泡沫密度不均匀。来自 SLG 的 BC 颗粒由于其窄的尺寸分布、改善的分散性和介孔表面而成为最有效的成核剂。这项工作表明，BC 可以作为 PLA 的有效生物成核剂。
Improvement and new technologies for effective poly (lactic acid) (PLA) foaming are still in developing. This study examines the ability of biochar (BC) to assist in PLA foaming through a supercritical CO2batch process. To determine suitable foaming parameters, process optimization was conducted on neat PLA films. BC particles derived from three different sources – sludge (SLG), pistachio shells (PST) and green waste (GW) were ground, and ball milled to a microscale and then blended with PLA. The PLA/BC blends were extruded into films and then batch foamed. The effect of BC was found to be concentration and source dependent. At 0.25 wt%, BC particles were found to be effective nucleating agents showing an increase up to four orders of magnitude in cell density and 10-fold reduction in the mean pore size compared to the neat PLA foams. An increase in BC content to 0.5 and 1 wt% induced particle aggregation, which resulted in non-homogenous foam densities. BC particles derived from SLG were the most effective nucleating agents due to their narrow size distribution, improved dispersibility and mesoporous surface. This work shows that BC can act as an effective bio-derived nucleating agent for PLA.