Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
ACS Appl Mater Interfaces. 2009 Oct;1(10):2390-9. doi: 10.1021/am900514v.
Renewable composites were prepared by melt blending of polylactide and soybean oil. The blend morphology was tuned by the addition of poly(isoprene-b-lactide) block copolymers. Due to the extreme difference in the viscosities of soybean oil and polylactide, a critical block copolymer composition was found to induce a phase inversion point at which the minor soybean oil phase became the matrix surrounding polylactide particles. This transition was due to the thermodynamic interactions between the block copolymer and the two phases and shear forces acting on the mixture during blending. The size of the soybean oil droplets in the polylactide matrix was also highly dependent on the block copolymer composition. In binary polylactide/soybean oil blends, there was a limiting concentration of soybean oil that could be incorporated into the polylactide matrix (6% of the total blend weight), which could be increased up to 20% by the addition of block copolymers.
采用聚乳酸和大豆油熔融共混的方法制备可再生复合材料。通过添加聚（异戊二烯-b- 乳酸）嵌段共聚物来调节共混物的形态。由于大豆油和聚乳酸的粘度差异极大，发现临界嵌段共聚物组成会诱导相反转点，此时少量的大豆油相成为聚乳酸颗粒的基体。这种转变是由于嵌段共聚物与两相之间的热力学相互作用以及共混过程中混合物受到的剪切力。聚乳酸基体中的大豆油液滴的尺寸也高度依赖于嵌段共聚物的组成。在二元聚乳酸/大豆油共混物中，大豆油的极限浓度可掺入聚乳酸基体中（占总共混物重量的 6%），通过添加嵌段共聚物可将其提高至 20%。
