碱木质素对聚乳酸发泡性能的影响

Effect of Alkali Lignin on Foaming Properties of Polylactic Acid

以超临界CO_(2)为物理发泡剂,采用间歇发泡法制备了碱木质素-聚乳酸(AL-PLA)开孔泡沫材料。研究碱木质素的质量分数对聚乳酸结晶行为、流变性能以及聚乳酸开孔泡沫的泡孔形态和泡孔分布的影响。结果表明:添加适量的碱木质素,不仅可以提高聚乳酸的结晶度,而且可以改善聚乳酸的发泡性能,当碱木质素的质量分数为1.0%时,所制备的聚乳酸泡沫的表观密度仅为0.033 g·cm^(-3)、发泡倍率高达36.88倍、平均泡孔尺寸为59.7μm,该聚乳酸泡沫具有更低的表观密度、更高的发泡倍率以及更小的泡孔尺寸。

Alkali lignin-polylactic acid open-cell foam was prepared by intermittent foaming method with supercritical CO_(2) as physical foaming agent.The effects of alkali lignin content on the crystallization behavior and rheological properties of polylactic acid,as well as the cell morphology and cell distribution of open-cell polylactic acid foams were mainly studied.The results show that adding an appropriate amount of alkali lignin can not only improve the crystallinity of polylactic acid,but also improve the foaming performance of polylactic acid.When the content of alkali lignin is 1.0%,the apparent density is only 0.033 g·cm^(-3),the foaming ratio is as high as 36.88 times,and the average cell size is 59.7μm.The PLA foam has lower apparent density,higher foaming ratio and smaller cell size.