National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, São Carlos, SP 13561-206, Brazil.
National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, São Carlos, SP 13561-206, Brazil; Graduate Program in Materials Science and Engineering (PPG-CEM), Federal University of São Carlos, São Carlos, SP 13565-905, Brazil.
Carbohydr Polym. 2017 Jul 1;167:177-184. doi: 10.1016/j.carbpol.2017.03.051. Epub 2017 Mar 18.
Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL) were prepared in a co-rotating twin screw extruder. The UTPS and PCL content varied in a range of 25wt%. The materials were characterized by capillary rheometry, scanning electron microscopy (SEM), termogravimetry (TGA), differential scanning calorimetry (DSC) and tensile tests. Capillary rheometry showed better interaction between UTPS and PCL at 110°C than at 130°C. SEM showed immiscibility of all blends and good dispersion of UTPS in PCL matrix up to 50wt%. However, a co-continuous morphology was found for UTPS/PCL 75/25. Thermal analysis showed that introducing PCL in UTPS, increased T due to higher thermal stability of PCL, and blends presented an intermediate behavior of neat polymers. The presence of PCL in blends improved significantly the mechanical properties of neat UTPS. Because they are totally biodegradable, these blends can be vehicles for controlled or slow release of nutrients to the soil while degraded.
在同向旋转双螺杆挤出机中制备了可生物降解的尿素增塑热塑性淀粉（UTPS）和聚（ε-己内酯）（PCL）共混物。UTPS 和 PCL 的含量在 25wt%范围内变化。通过毛细管流变仪、扫描电子显微镜（SEM）、热重分析（TGA）、差示扫描量热法（DSC）和拉伸试验对材料进行了表征。毛细管流变学表明，在 110°C 下 UTPS 和 PCL 之间的相互作用优于在 130°C 下。SEM 显示所有共混物均不混溶，UTPS 在 PCL 基体中的分散性良好，最高可达 50wt%。然而，在 UTPS/PCL 75/25 中发现了共连续形态。热分析表明，由于 PCL 的热稳定性更高，在 UTPS 中引入 PCL 会增加 T，并且共混物表现出与纯聚合物的中间行为。PCL 在共混物中的存在显著提高了纯 UTPS 的力学性能。由于它们是完全可生物降解的，因此这些共混物可以作为载体，在降解过程中向土壤中控制或缓慢释放营养物质。
