Toughening of Biodegradable Polylactide/Poly(butylene succinate-co-adipate) Blends via in Situ Reactive Compatibilization
Toughening of Biodegradable Polylactide/Poly(butylene succinate-co-adipate) Blends via in Situ Reactive Compatibilization
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DOI：
10.1021/am400482f
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发表时间：
2013-05-22
影响因子：
9.5
通讯作者：
Sadiku, Rotimi
中科院分区：
文献类型：
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作者：
Ojijo, Vincent;Ray, Suprakas Sinha;Sadiku, Rotimi
在亚磷酸三苯酯（TPP）存在下，将聚乳酸与聚丁二酸-己二酸丁二醇酯（PLA/PBSA）进行熔融共混。在熔融混合过程中的扭矩的增加被用来监测粘度的变化作为共混物的增容发生。扫描电子显微镜显示，不仅减少了分散相的大小与TPP的含量增加，但也原纤化的PLA和PBSA相之间的链接，表示相容。此外，对混合顺序和时间、TPP含量和PBSA浓度等参数的优化表明，含有30和10wt%PBSA和2wt%TPP的共混物（加工30 min）的热机械性能最佳。冲击强度从PLA的6 kJ/m2分别增加到含有30和10 wt % PBSA的共混物的11和16 kJ/m2，而断裂伸长率从PLA的6%分别增加到含有30和10 wt % PBSA的共混物的20和37%。增容后，由于两相间的脱粘，材料的破坏模式由PLA的脆性断裂转变为韧性变形。相容化后的共混物不仅增韧，而且拉伸强度和热稳定性也没有明显下降。
Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m2 for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.