Effects of the matrix crystallinity, dispersed phase, and processing type on the morphological, thermal, and mechanical properties of polylactide‐based binary blends with poly[(butylene adipate)‐co‐terephthalate] and poly[(butylene succinate)‐co‐adipate]

Abstract

In this study, we prepared immiscible blends of 75 wt % polylactide (PLA) with 25 wt % poly[(butylene adipate)-co-terephthalate] (PBAT) through an injection-molding (IM) process and a twin-screw extruder (TSE) followed by IM. An amorphous polylactide (A-PLA) and a semicrystalline polylactide (SC-PLA) were used as the matrixes to investigate the matrix crystallization effect on the morphology and property development of the blends with only IM. A blend of A-PLA with 25 wt % poly[(butylene succinate)-co-adipate] (PBSA) was also prepared through IM to compare its properties with those of the A-PLA-PBAT blends. The morphological, thermal, solid viscoelastic, tensile, and flexural properties of the blends were compared, and their dependency on the evolution of the blend morphology was analyzed. The tensile results show that when IM was used as the sole processing technique, the ductility and toughness were significantly improved only when SC-PLA was used as the matrix. Preprocessing through TSE also resulted in the enhancement of the blend ductility. In A-PLA-PBSA, the vitrification of PLA hindered the crystallization of PBSA to very low temperatures (<0 C) and resulted in a very nonuniform structure with weak intermolecular bonding between phases.

Effect of TPU hard segment content on the rheological and mechanical properties of PLA/TPU blends

“…These PLA samples that are referred to as aPLA and scPLA, respectively, possess melt flow rate values of around 7-10 and 8 g/10 min at 210 C. [6] The transition temperatures, crystallization, and thermal behaviors of these two PLA grades are compared in detail in our previous study. [24] Three TPU grades based on pTHF polyether polyol were custom made and kindly supplied from Huntsman Polyurethanes, Kortenberg, Belgium. The TPUs possessed similar SS molecular weights of around 1,000 g/mol and contained HS of 40.3, 50.8, and 55.8 wt%.…”

“…[22,23] The processing type could also influence the droplet structure and hence the final properties could be affected by the sample preparation. [24] Thermoplastic polyurethane (TPU) is an elastomeric polymer with a unique combination of properties such as high ductility, toughness, durability, flexibility, biocompatibility, and biostability. TPU's molecular configuration includes hard and soft blocks that, due to their polarity differences, could be phase separated.…”

Nanoparticle Interactions and Molecular Relaxation in PLA/PBAT/Nanoclay Blends

“…Polymer blending is used to obtain tailored combinations of properties (Favis, 1991;Macosko, 2000;Nofar et al, 2019b). The morphological characteristics of a binary polymer blend are determined by thermodynamics, processing conditions, type of dispersed phase, and viscoelastic behavior of the polymers under melt blending conditions (Favis & Chalifoux, 1987;Favis & Therrien, 1991;2017;2019a;2019b;Scott & Macosko, 1991;Souza & Demarquette, 2002;Sundararaj et al, 1995). Blend nanocomposites are systems that exhibit variety of microstructures Maani & Carreau, 2016;Nofar et al, n.d.).…”

The Effects of Inorganic Salts with Different Anions on the Structure and Properties of Starch/Poly (Butylene Succinate) Blends Plasticized with Ionic Liquid

“…Figure 6a,b show the X-ray diffraction spectra of the TSP blends and TSP blends modified with different inorganic salts. The previous studies have proved that PBS has three diffraction peaks when 2θ angles are 19.5, 21.5, and 22.5 • , corresponding to (020), (021), and (110) crystal planes [33][34][35], respectively. It could be seen from Figure 6 that the diffraction peak positions of the TSP blends do not move or change as the increase of the MgSO 4 or MgCl 2 .…”