Tuancharoensri Nantaprapa, Ross Gareth M, Kongprayoon Arisa, Mahasaranon Sararat, Pratumshat Supatra, Viyoch Jarupa, Petrot Narin, Ruanthong Wuttipong, Punyodom Winita, Topham Paul D, Tighe Brian J, Ross Sukunya
Biopolymer Group, Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
Center of Excellence in Biomaterials, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
Polymers (Basel). 2023 Jan 6;15(2):303. doi: 10.3390/polym15020303.
Ternary-blended, melt-blown films of polylactide (PLA), polycaprolactone (PCL) and cellulose acetate butyrate (CAB) were prepared from preliminary miscibility data using a rapid screening method and optical ternary phase diagram (presented as clear, translucent, and opaque regions) as a guide for the composition selection. The compositions that provided optically clear regions were selected for melt blending. The ternary (PLA/PCL/CAB) blends were first melt-extruded and then melt-blown to form films and characterized for their tensile properties, tensile fractured-surface morphology, miscibility, crystallinity, molecular weight and chemical structure. The results showed that the tensile elongation at the break (%elongation) of the ternary-blended, melt-blown films (85/5/10, 75/10/15, 60/15/25 of PLA/PCL/CAB) was substantially higher (>350%) than pure PLA (ca. 20%). The range of compositions in which a significant increase in %elongation was observed at 55−85% w/w PLA, 5−20% w/w PCL and 10−25% w/w CAB. Films with high %elongation all showed good interfacial interactions between the dispersed phase (PCL and CAB) and matrix (PLA) in FE-SEM and showed improvements in miscibility (higher intermolecular interaction and mixing) and a decrease in the glass transition temperature, when compared to the low %elongation films. The decrease in Mw and Mn and the formation of the new NMR peaks (1H NMR at 3.68−3.73 ppm and 13C NMR at 58.54 ppm) were observed in only the high %elongation films. These are expected to be in situ compatibilizers that are generated during the melt processing, mostly by chain scission. In addition, mathematical modelling was used to study the optimal ratio and cost-effectiveness of blends with optimised mechanical properties. These ternary-blended, melt-blown films have the potential for use in both packaging and medical devices with excellent mechanical performance as well as inherent economic and environmental capabilities.
利用快速筛选方法，根据初步的互溶性数据，并以光学三元相图（呈现为透明、半透明和不透明区域）作为成分选择的指导，制备了聚乳酸（PLA）、聚己内酯（PCL）和醋酸丁酸纤维素（CAB）的三元共混熔喷薄膜。选择提供光学透明区域的成分进行熔融共混。三元（PLA/PCL/CAB）共混物首先进行熔融挤出，然后进行熔喷以形成薄膜，并对其拉伸性能、拉伸断裂表面形态、互溶性、结晶度、分子量和化学结构进行表征。结果表明，三元共混熔喷薄膜（PLA/PCL/CAB的比例为85/5/10、75/10/15、60/15/25）的断裂伸长率（%伸长率）显著高于纯PLA（约20%），高达350%以上。在PLA含量为55−85% w/w、PCL含量为5−20% w/w和CAB含量为10−25% w/w的范围内，观察到%伸长率有显著增加。高%伸长率的薄膜在场发射扫描电子显微镜（FE-SEM）中均显示出分散相（PCL和CAB）与基体（PLA）之间良好的界面相互作用，与低%伸长率的薄膜相比，互溶性有所改善（分子间相互作用和混合程度更高），玻璃化转变温度降低。仅在高%伸长率的薄膜中观察到分子量（Mw）和数均分子量（Mn）的降低以及新的核磁共振峰的形成（1H NMR在3.68−3.73 ppm处，13C NMR在58.54 ppm处）。这些有望是在熔融加工过程中主要通过断链产生的原位增容剂。此外，使用数学建模来研究具有优化机械性能的共混物的最佳比例和成本效益。这些三元共混熔喷薄膜具有用于包装和医疗设备的潜力，具有优异的机械性能以及固有的经济和环境优势。
