Tian Fangwei, Huang Hanyi, Li Yaozong, Zhai Wentao
School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Materials (Basel). 2024 Jul 27;17(15):3712. doi: 10.3390/ma17153712.
The soft PBAT foam shows good flexibility, high elasticity, degradable nature, and it can be used as an environmental-friendly candidate for EVA and PU foams. Unfortunately, there are few reports on the application of PBAT as a soft foam. In this study, PBAT foam was fabricated by a pressure quenching method using CO as the blowing agent. A significant volume shrinkage of about 81% occurred, where the initial PBAT foam had an extremely high expansion ratio, of about 31 times. A 5-10 wt% PBS with high crystallinity was blended, and N with low gas solubility and diffusivity was mixed, with the aim of resisting foam shrinkage and preparing PBAT with a high final expansion ratio of 14.7 times. The possible mechanism behind this phenomenon was established, and the increased matrix modulus and decreased pressure difference within and outside the cell structure were the main reasons for the shrinkage resistance. The properties of PBAT and PBAT/PBS foams with a density of 0.1 g/cm were measured, based on the requirements for shoe applications. The 5-10 wt% PBS loading presented advantages in reducing thermal shrinkage at 75 °C/40 min, without compromising the hardness, elasticity, and the compression set, which ensures that PBAT/PBS foams have good prospects for use as soft foams.
柔软的聚己二酸/对苯二甲酸丁二醇酯（PBAT）泡沫具有良好的柔韧性、高弹性和可降解性，可作为乙烯-醋酸乙烯酯共聚物（EVA）和聚氨酯（PU）泡沫的环保替代品。遗憾的是，关于PBAT作为软质泡沫应用的报道很少。在本研究中，采用以CO作为发泡剂的压力猝灭法制备了PBAT泡沫。出现了约81%的显著体积收缩，初始PBAT泡沫具有极高的膨胀比，约为31倍。将5-10 wt%的高结晶度聚丁二酸丁二醇酯（PBS）进行共混，并混入气体溶解度和扩散率较低的N，目的是抵抗泡沫收缩并制备最终膨胀比高达14.7倍的PBAT。确定了这一现象背后的可能机制，基体模量的增加和泡孔结构内外压力差的减小是抗收缩的主要原因。根据鞋类应用的要求，测量了密度为0.1 g/cm³的PBAT和PBAT/PBS泡沫的性能。5-10 wt%的PBS添加量在75 °C/40 min下减少热收缩方面具有优势，同时不影响硬度、弹性和压缩永久变形，这确保了PBAT/PBS泡沫作为软质泡沫具有良好的应用前景。
