In this work, poly(lactic acid), PLA and thermoplastic starch, TPS blends (with a fixed 11 content of 30 wt.% TPS) were prepared by melt extrusion process to increase the low ductile 12

The effect of three additives derived from pine resin, namely, gum rosin (GR) and two pentaerythritol ester of GR, Lurefor (LF) and Unik Tack (UT), in 5, 10, and 15 wt %, on the properties of Mater‐Bi, based on plasticized starch, poly(butylene adipate‐co‐terephthalate), and poly(ε‐caprolactone) (PCL), obtained by injection molding processes, was studied. The mechanical, microstructural, and thermal properties were evaluated. LF had a cohesive behavior with the components of Mater‐Bi, increasing the toughness of the material up to 250% accompanied by an increase of tensile modulus and tensile strength. UT had an intermediate behavior, conferring cohesive and plasticizing effects, allowing an increase of 105% in impact resistance. GR had a more marked plasticizing effect. This allows processing temperatures of about 50 °C lower than those used for neat Mater‐Bi. In addition, an increase of the elongation at break, toughness, and impact resistance in 370, 480, and 250%, respectively, was achieved. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48236.

2 AbstractThe present work is focused on the development of binary blends from poly(hydroxybutyrate) (PHB) and poly(caprolactone) (PCL). Miscibility, mechanical and thermal properties as well as blends morphology are evaluated in terms of the blend composition. Binary PHB-PCL blends were manufactured by melt compounding in a twin screw co-rotating extruder and injection molded. Composition of PHB-PCL covered the full range between individual polymers at 25 wt% increments. The obtained results show that PCL acts as an impact modifier thus leading to an increase in flexibility and ductility as the PCL content on PHB-PCL blends increases with a noticeable increase in elongation at break and on

In this work, binary blends based on poly(lactic acid)-PLA and poly(caprolactone)-PCL were prepared by melt mixing in a twin screw co-rotating extruder in order to increase the low intrinsic elongation at break of PLA for packaging applications. Although PLA and PCL show low miscibility, presence of PCL leads to a remarkable increase in ductile properties of PLA.Different mechanical properties were evaluated in terms of PCL content up to 30 weight % PCL. Additionally to tensile and flexural properties, the Poisson's ratio was obtained by using bi-axial extensometry to evaluate transversal deformations when axial loads are applied. Very slight changes in the melt temperature (T m ) and glass transition temperature (T g ) of PLA were observed thus indicating low miscibility of the PLA-PCL system. Field emission scanning electron microscopy (FESEM) revealed some interactions between the two components of the blend since the morphology is characterized by non-spherical poly(caprolactone) drops dispersed into the PLA matrix. In addition to the improvement of mechanical ductile properties, PCL provides higher degradation rates of blends under conditions of composting for contents below 22.5% PCL.Keywords: Poly(lactic acid)-PLA; poly(caprolactone)-PCL; binary blends; FESEM; mechanical properties; disintegrability. 1.-Introduction.Nowadays, polymers find a broad number of applications in the fields of packaging, medical and automotive industries due to an excellent balance between processing and overall properties [1]. Among all these polymers, aliphatic polyesters from both renewable and/or fossil fuel resources [2] Poly(lactic acid) is one of the most used biocompostable polymers in packaging applications due to its high mechanical performance and balanced barrier properties [16,17].PLA is widely used in the manufacturing of biodegradable/biocompostable films for food applications. The main drawback related to PLA is its high intrinsic fragility that is still accentuated as degradation occurs. PLA has low ductility at room temperature because its glass transition temperature (T g ) is located at around 60 ºC; so that, below its T g , it behaves as a glass characterized by high mechanical resistance and modulus and high fragility together with low elongation at break (due to restricted polymer chain mobility below T g ). Conventional plasticizers could potentially be used to allow some elongation at break but typical plasticizers can migrate and this could be responsible for a toxicity as well as a decrease in mechanical properties [18][19][20]. Another alternative is copolymerization. By using copolymerization processes with appropriately selected monomers it is possible to tailor PLA properties to desired performance. Some examples of PLA-based copolymers are poly(lactic acid-co--caprolactone)-PLACL, poly(lactic acid-co-ethylene glycol)-PLAEG, poly(hydroxibutirate-cohydroxivalerate)-PHBV, etc [21,22]. Nevertheless these copolymers are expensive. One attracting solution is manufacturing of binary or ternary...

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