Polymer blends of poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) have been drawn attention due to the application potential as packaging or agricultural films. This study aims to determine the manufacturability, miscibility and mechanical properties of uncompatibilized PBAT/PLA blends prepared using different techniques. First, PBAT and PLA are melt-blended in a wide range of ratios from 90/10 to 10/90. The compounds are then processed into pressed panels, flat films and blown films. Finally, the thermal, morphological, rheological and mechanical properties of these blends are investigated. PBAT/PLA blends have a small difference of solubility parameters, predicting theoretically good miscibility. However, they show two almost unchanged glass transition temperatures in the DSC, phase separation in SEM and two relaxation mechanisms in the Cole–Cole plot. The phase morphology varies depending on both the blend ratios and the preparation techniques. Tensile tests indicate that with increasing PLA content the elongation at break decreases. A good correlation between the elongation at break and the tear propagation resistance is found. Furthermore, the trouser tear method is proven to be more applicable to differentiate highly extensible blown films compared with the Elmendorf tear method.

Biodegradable plastics are experiencing increasing demand, in particular because of said property. This also applies to the two biopolyesters poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) covered in this study. Both are proven to be biodegradable under industrial composting conditions. This study presents the influence of mineral fillers on the disintegration process of PLA/PBS blend systems under such conditions. Chalk and talc were used as fillers in PLA/PBS (7:3) blend systems. In addition, unfilled PLA/PBS (7:3/3:7) blend systems were considered. Microscopic images, differential scanning calorimetry and tensile test measurements were used in addition to measuring mass loss of the specimen to characterize the progress of disintegration. The mineral fillers used influence the disintegration behavior of PLA/PBS blends under industrial composting conditions. In general, talc leads to lower and chalk to higher disintegration rates. This effect is in line with the measured decrease in mechanical properties and melting enthalpies. The degrees of disintegration almost linearly correlate with specimen thickness, while different surface textures showed no clear effects. Thus, we conclude that disintegration in a PLA/PBS system proceeds as a bulk erosion process. Using fillers to control the degradation process is generally regarded as possible.