Fracture behavior and mechanical, thermal, and rheological properties of biodegradable films extruded by flat die and calender

Abstract

The development of biodegradable materials for tailored applications, particularly in the field of polymeric films and sheets, is a challenging technological goal as well as a contribution to help protect the environment. Poly(lactic) acid (PLA) is a promising substitute for several oil-based polymers; however, to overcome its thermal and mechanical drawbacks, researchers have developed solutions such as blending PLA with polybutylene adipate terephthalate (PBAT), which is capable of increasing the ductility of the final material. In this study, PLA/PBAT binary blends, with minimum possible content of nonrenewable materials, were examined from processing, thermal, morphological, and rheological perspective. An optimized PLA/PBAT ratio was chosen as the polymeric basis to obtain a biodegradable formulation by adding a biobased plasticizer and appropriate fillers to produce a micrometer film with tailored flexibility and tear resistance. The processing technology involved flat-die extrusion, followed by calendering. The tearing resistance of the produced film was investigated, and the results were compared with literature data. A study on the essential work of fracture was implemented to explore the mode III out-of-plane fracture resistance starting from a trouser tear test.

Structure–Property Relationships in Bionanocomposites for Pipe Extrusion Applications

“…In addition, MB1 and MB2 exhibit an improved deformability with respect to HDPE, recognizable in the higher BSR values that were reached from these samples, while the stretchability of the BF material is quite similar to that of HDPE. As far as the nanocomposites are concerned, their general behavior reflects the previously discussed results about the shear viscosity, as usually higher values of MS are expected for the materials showing higher viscosity [40]. Interestingly, the HDPE + Socal nanocomposite exhibits a decreased MS with respect to the unfilled matrix, notwithstanding its slightly enhanced shear viscosity values.…”

“…As far as the nanocomposites are concerned, their general behavior reflects the previously discussed results about the shear viscosity, as usually higher values of MS are expected for the materials showing higher viscosity [ 40 ]. Interestingly, the HDPE + Socal nanocomposite exhibits a decreased MS with respect to the unfilled matrix, notwithstanding its slightly enhanced shear viscosity values.…”

Bionanocomposite Blown Films: Insights on the Rheological and Mechanical Behavior

“…As far as the values of ultimate tensile strength are concerned ( Table 2 and Figure 5 B), nanocomposites based on LDPE and MB1 exhibit improved values as compared to the unfilled matrices; differently, the introduction of both types of nanoclays causes a decrease of the UTS values for MB2-based systems. This behavior can be associated with the low ductility of the bionanocomposites ( Table 2 and Figure 5 C) as compared to the unfilled matrix, inducing a premature failure of the samples during the test [ 45 ].…”

Rheology, Morphology and Thermal Properties of a PLA/PHB/Clay Blend Nanocomposite: The Influence of Process Parameters

“…The glass transition temperature (Tg), crystallization temperature (Tc), cold crystallization temperature (Tcc), melting temperature (Tm) and melting enthalpy (ΔHm) were determined from the first heating scan. The crystallinity percentage X in all investigated systems was evaluated as [30]:…”