Abstract
In this work, eco-sustainable blown films with improved performance, suitable for flexible packaging applications requiring high ductility, were developed and characterized. Films were made by blending two bioplastics with complementary properties—the ductile and flexible poly(butylene-adipate-co-terephthalate) (PBAT) and the rigid and brittle poly(lactic acid) (PLA)—at a 60/40 mass ratio. With the aim of improving the blends’ performance, the effects of two types of PLA, differing for viscosity and stereoregularity, and the addition of a commercial polymer chain extender (Joncryl®), were analyzed. The use of the PLA with a viscosity ratio closer to PBAT and lower stereoregularity led to a finer morphology and better interfacial adhesion between the phases, and the addition of the chain extender further reduced the size of the dispersed phase domains, with beneficial effects on the mechanical response of the produced films. The best system composition, made by the blend of PBAT, amorphous PLA, and the compatibilizer, proved to have improved mechanical properties, with a good balance between stiffness and ductility and also good transparency and sealability, which are desirable features for flexible packaging applications.
Highlights
The packaging sector is among the major consumers of plastic materials and, in this field, conventional non-biodegradable polymers are widely employed for their desirable properties.they become a major source of waste after use due to their poor biodegradability
The use of the Poly(lactic acid) (PLA) with a viscosity ratio closer to Poly(butylene adipate-co-terephthalate) (PBAT) and lower stereoregularity led to a finer morphology and better interfacial adhesion between the phases, and the addition of the chain extender further reduced the size of the dispersed phase domains, with beneficial effects on the mechanical response of the produced films
We focused our attention on PBAT/PLA blends with a high content of PBAT: these systems could be of great importance for applications where high ductility is required, such as packaging applications at low storage temperature, as demonstrated in our previous work [9]
Summary
The packaging sector is among the major consumers of plastic materials and, in this field, conventional non-biodegradable polymers are widely employed for their desirable properties.they become a major source of waste after use due to their poor biodegradability. Its poor stiffness, low transparency, and low seal strength until now have limited its use [4] In this context, the melt blending of PBAT with another bioplastic could represent an effective and economic way to improve its properties without compromising its biodegradability. Poly(lactic acid) (PLA), is a bio-based and biodegradable polyester with good processability and interesting properties in the packaging field that could be customized by varying the relative content of the D and L isomers [5,6]. It has high transparency and complementary mechanical properties to PBAT, exhibiting high stiffness and high brittleness [7,8]. The melt blending of these two polymers, by varying the mass ratio of PLA and PBAT in the blend, Materials 2020, 13, 5395; doi:10.3390/ma13235395 www.mdpi.com/journal/materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
