Department of Chemical Engineering, Laval University, Quebec, QC G1V 0A6, Canada.
Molecules. 2022 Oct 12;27(20):6819. doi: 10.3390/molecules27206819.
Fully biobased polylactide (PLA)/polyamide-11 (PA11) blends were prepared by melt mixing with an elastomer intermediate phase to address the low elasticity and brittleness of PLA blends. The incorporation of a biobased elastomer made of poly(butylene adipate-co-terephthalate) (PBAT) and polyethylene oxide (PEO) copolymers was found to change the rigid interface between PLA and PA11 into a much more elastic/deformable one as well as promote interfacial compatibility. The interfacial tension of the polymer pairs and spreading coefficients revealed a high tendency of PEO to spread at the PLA/PA11 interface, resulting in a complete wetting regime (interfacial tension of 0.56 mN/m). A fully percolated rubbery phase (PEO) layer at the PLA/PA11 interface with enhanced interfacial interactions and PLA chain mobility contributed to a better distribution of the stress around the dispersed phase, leading to shear yielding of the matrix. The results also show that both the morphological modification and improved compatibility upon PEO addition (up to 20 wt %) contributed to the improved elongation at break (up to 104%) and impact strength (up to 292%) of the ternary PLA/PA11/PEO blends to obtain a super-tough multiphase system.
完全生物基聚乳酸（PLA）/聚酰胺-11（PA11）共混物通过熔融混合制备，其中包含弹性体中间相，以解决 PLA 共混物弹性低和脆性大的问题。发现加入由聚（己二酸丁二醇酯-co-对苯二甲酸）（PBAT）和聚氧化乙烯（PEO）共聚物组成的生物基弹性体，可将 PLA 和 PA11 之间的刚性界面转变为更具弹性/可变形的界面，并促进界面相容性。聚合物对的界面张力和扩展系数表明，PEO 具有在 PLA/PA11 界面上扩展的高趋势，导致完全润湿状态（界面张力为 0.56 mN/m）。在 PLA/PA11 界面处形成完全渗透的橡胶状（PEO）层，增强了界面相互作用和 PLA 链迁移性，有助于在分散相周围更均匀地分布应力，导致基体发生剪切屈服。结果还表明，PEO 的添加（高达 20wt%）在形态改性和提高相容性方面都有助于提高共混物的断裂伸长率（高达 104%）和冲击强度（高达 292%），从而获得超韧多相体系。
