Blown film extrusion of poly(lactic)acid/poly(3‐hydroxybutyrate‐4‐hydroxybutyrate) blends for improved toughness and processability

Abstract

Poly(lactic acid) is one of the most commonly used bioplastics thanks to its mechanical performance and low environmental impact. Strategies to overcome excessive rigidity of PLA are constantly investigated. Poor viscoelastic behavior and brittleness of PLA seriously limit its potential application as a common film material. Herein highly amorphous Poly(3‐hydroxybutyrate‐4‐hydroxybutyrate) (P(3HB)(4HB)) was introduced to improve toughness and reduce brittleness of PLA. Anti‐blocking (silica) and anti‐slipping agent (Ethylene bis‐stearamide (EBS)) were added to improve the processability of the blends, specifically to solve winding issues of the blown film and unfolding of the layflat. In this study three formulations containing PLA and different ratios of P(3HB)(4HB), specifically 10–20–30% were extruded. The mechanical, thermal and surface characterization of the films was performed. The tensile and the tear strength test results show that P(3HB)(4HB) increased the ductility of PLA based films. Increasing amounts of P(3HB)(4HB) provide a toughening effect on PLA/P(3HB)(4HB) blown films without altering transparency of PLA. Moreover, the processing additives proved to be efficient in improving film blowing stability and avoiding tackiness during the winding phase of the film.

Mechanical and Rheological Evaluation of Polyester-Based Composites Containing Biochar

“…Ecovio ® F Mulch C2311 (PBAT/PLA), BASF Company (Florham Park, NJ, USA), a commercial blend of PBAT (47 mol% of aromatic segments) with 25 mol% of PLA (determined by nuclear magnetic resonance spectroscopy), as described in previous work [5], and SOOGREEN 2001a (PLA/P(3HB-co-4HB)) with 12% of 4-hydroxybutyrate (4-HB) units in P(3HB-co-4HB), 78% PLA units in blend, and 1 mol% plasticizer acetyl tributyl citrate (ATBC) (calculated by proton nuclear magnetic resonance spectroscopy), from Tianjin GreenBio Materials (Tianjin GuoYun Biological Material Co., Ltd., Tianjin, China), were utilized as a matrix for composites with different amounts (10, 15, 20 and 30 wt%) of biochar. PBAT/PLA blends and (PLA/P(3HB-co-4HB)) blends have been reported in several publications [16][17][18][19].…”