Przybysz-Romatowska Marta, Haponiuk Józef, Formela Krzysztof
Department of Polymer Technology, Faculty of Chemistry, Gdansk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland.
Polymers (Basel). 2020 Jan 16;12(1):228. doi: 10.3390/polym12010228.
Poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) blends were compatibilized by reactive blending and by copolymers formed during reaction in the solution. The reactive blending of PCL/PLA was performed using di-(2-tert-butyl-peroxyisopropyl)benzene (BIB) or dicumyl peroxide (DCP) as radical initiator. PCL--PLA copolymers were prepared using 1.0 wt. % of DCP or BIB via reaction in solution, which was investigated through a Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) in order to better understand the occurring mechanisms. The effect of different additions such as PCL--PLA copolymers, DCP, or BIB on the properties of PCL/PLA blends was studied. The unmodified PCL/PLA blends showed a sea-island morphology typical of incompatible blends, where PLA droplets were dispersed in the PCL matrix. Application of organic peroxides improved miscibility between PCL and PLA phases. A similar effect was observed for PCL/PLA blend compatibilized by PCL--PLA copolymer, where BIB was used as initiator. However, in case of application of the peroxides, the PCL/PLA blends were cross-linked, and it has been confirmed by the gel fraction and melt flow index measurements. The thermal and mechanical properties of the blends were also investigated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and tensile strength.
聚（ε-己内酯）（PCL）与聚乳酸（PLA）共混物通过反应性共混以及在溶液反应过程中形成的共聚物实现了增容。PCL/PLA的反应性共混使用二（2-叔丁基过氧异丙基）苯（BIB）或过氧化二异丙苯（DCP）作为自由基引发剂。通过在溶液中反应，使用1.0 wt.%的DCP或BIB制备PCL-PLA共聚物，并通过傅里叶变换红外光谱（FTIR）和核磁共振（NMR）对其进行研究，以便更好地理解发生的机理。研究了不同添加剂如PCL-PLA共聚物、DCP或BIB对PCL/PLA共混物性能的影响。未改性的PCL/PLA共混物呈现出不相容共混物典型的海岛形态，其中PLA液滴分散在PCL基体中。有机过氧化物的应用改善了PCL和PLA相之间的相容性。对于以BIB作为引发剂、由PCL-PLA共聚物增容的PCL/PLA共混物，也观察到了类似的效果。然而，在使用过氧化物的情况下，PCL/PLA共混物发生了交联，这已通过凝胶分数和熔体流动指数测量得到证实。还通过差示扫描量热法（DSC）、热重分析（TGA）、动态力学分析（DMA）和拉伸强度对共混物的热性能和力学性能进行了研究。
