Improvement of PBAT Processability and Mechanical Performance by Blending with Pine Resin Derivatives for Injection Moulding Rigid Packaging with Enhanced Hydrophobicity

Abstract

Polybutylene adipate-co-terephthalate (PBAT) is a biodegradable polymer with good features for packaging applications. However, the mechanical performance and high prices of PBAT limit its current usage at the commercial level. To improve the properties and reduce the cost of PBAT, pine resin derivatives, gum rosin (GR) and pentaerythritol ester of GR (UT), were proposed as sustainable additives. For this purpose, PBAT was blended with 5, 10, and 15 wt.% of additives by melt-extrusion followed by injection moulding. The overall performance of the formulations was assessed by tensile test, microstructural, thermal, and dynamic mechanical thermal analysis. The results showed that although good miscibility of both resins with PBAT matrix was achieved, GR in 10 wt.% showed better interfacial adhesion with the PBAT matrix than UT. The thermal characterization suggested that GR and UT reduce PBAT melting enthalpy and enhance its thermal stability, improving PBAT processability. A 10 wt.% of GR significantly increased the tensile properties of PBAT, while a 15 wt.% of UT maintained PBAT tensile performance. The obtained materials showed higher hydrophobicity than neat PBAT. Thus, GR and UT demonstrated that they are advantageous additives for PBAT–resin compounding for rigid food packaging which are easy to process and adequate for industrial scalability. At the same time, they enhance its mechanical and hydrophobic performance.

Films Based on Thermoplastic Starch Blended with Pine Resin Derivatives for Food Packaging

“…The revalorization of food and agro-industrial wastes into environmentally friendly materials has considerably increased during the last years [ 14 , 24 ]. In this sense, the revalorization of pine resin and gum rosin derivatives has gained interest in the food packaging field during the last years as natural low-cost additives (i.e., stabilizers, compatibilizers, and/or plasticizers) [ 18 , 19 , 25 , 26 , 27 ]. Resin is exudated from Conifers as a defense mechanism in wounds of their tissues or cuts of the wood of the stem [ 28 ].…”

Films Based on Mater-Bi® Compatibilized with Pine Resin Derivatives: Optical, Barrier, and Disintegration Properties

“…GR significantly increases MB hydrophobicity in a content of 5 wt.% due to the hydrophobicity of resin and the increased roughness of the surface (see Figure S3) [33]. However, when the content is raised to 10 or 15 wt.%, MB hydrophobicity is significatively reduced (p < 0.05).…”

“…These esters are widely used in paints, varnishes, adhesives, packaging, and drug microcapsules [27,31]. Moreover, pentaerythritol gum rosin esters are ecological and approved by the FDA [31], and thus are gaining interest in the sustainable food packaging sector [19,30,[32][33][34].…”

Study of the Properties of a Biodegradable Polymer Filled with Different Wood Flour Particles

“…Biopolyesters have emerged as the most promising sustainable polymers to replace traditional thermoplastics used for packaging materials, mainly due to their easy processability because of their available processing technologies at the industrial level (i.e., melt blending, extrusion, injection molding, etc.) [ 5 , 6 ]. Additionally, great efforts have been made in rheological [ 7 ] and mechanical properties [ 3 ] research in biodegradable polymers.…”