PLA/PHB Blends: Biocompatibilizer Effects

Abstract

The purpose of this work was to formulate a fully bio-based blend with superior properties, based on two immiscible polymers: polylactic acid (PLA) and poly-hydroxy butyrate (PHB). To improve the miscibility between the polymeric phases, two different kinds of compatibilizers with a different chemical structure were used, namely, an ethylene oxide/propylene oxide block copolymer in the form of flakes and a mixture of two liquid surfactants with a variable lipophilic–hydrophilic index. The morphology of the blends and their thermal, mechanical, and rheological behavior were evaluated, aiming at assessing the influence of the selected compatibilizers on the microstructure and final properties of the systems. Morphological analyses of the compatibilized blends indicated that the liquid surfactant is more effective than the solid copolymer in inducing morphology refinement, as also suggested by results coming from rheological measurements. Furthermore, thermal analyses demonstrated that the presence of both kinds of compatibilizers induced an enhancement of the crystallinity content of blends. Finally, a remarkable increase of the elastic modulus values was obtained for the compatibilized blends as compared to the pure counterparts, with a consequent significant enhancement of the HDT values.

Poly(lactic Acid)–Biochar Biocomposites: Effect of Processing and Filler Content on Rheological, Thermal, and Mechanical Properties

“…All the materials were subjected to the following cycle: All the thermal parameters were evaluated on the second heating scan, erasing the previous thermal history and evaluating T g (glass transition temperature), T cc (cold crystallization temperature), T m (melting temperature), and X c (crystallinity degree) in controlled conditions. X c was calculated as the ratio between the heat of fusion of the sample (∆H = ∆H m − ∆H cc , ∆H m and ∆H cc being the specific melting and cold crystallization enthalpies, respectively), considering only the polymer fraction, and the heat of fusion of a 100% crystalline PLA (93 J/g [33]).…”

Pseudo-Ductility, Morphology and Fractography Resulting from the Synergistic Effect of CaCO3 and Bentonite in HDPE Polymer Nano Composite

“…A worthwhile point for further discussion of mechanical properties in this work is the consideration of structure–property relationship of rigid CaCO 3 and bentonite (nano clay) filler particles for polymer–fillers interfacial interaction. In order to achieve an adequate polymer–filler interfacial interaction, the study of Sahin et al [ 10 ] and D’Anna et al [ 11 ] asserts the application of surfactants and compatibilizer, respectively. The results explained in the work of Sahin and his co-worker, show that mechanical properties can be enhanced when there is an effective stress transfer from polymer to filler particles provided that the polymer fillers have compatible interfaces.…”

Dielectric, Thermal and Mechanical Properties of l,d-Poly(Lactic Acid) Modified by 4′-Pentyl-4-Biphenylcarbonitrile and Single Walled Carbon Nanotube

“…However, among disadvantages of l , d -PLA the most important ones are low glass transition temperature, low thermal stability, high brittleness and low crystallization rate. Binary and ternary mixtures or blends were created to improved selected properties of l , d -PLA and examples of some components are listed:a low molecular weight plasticizer, for example, acetyl tributyl citrate [30,31];polymers such as: poly(butylene adipate-co-terephthalate) [32,33] poly(butylene succinate) [34,35], poly(hydroxy butyrate) [36,37], polyaniline with multiwalled carbon nanotubes as flexible free-standing electrode for supercapacitors [38];carbon nanotubes [39,40,41,42,43,44,45];graphene and graphene oxide [46,47,48];liquid crystalline poly [4,4′-bis(6-hydroxyhexyloxy) biphenyl phenylsuccinate] as functional chain to copolymerize with PLA, towards improve the flexibility of PLA and caused interactions with multiwalled carbon nanotubes via π–π interaction [49];magnesium as filament based 3D printing [50];TiO 2 for antibacterial packaging [51];ZnO as potential antimicrobial food packaging materials [52];high-density polyethylene/carbon black composites as electrically conductive composites with a low percolation threshold [53]. …”

“…polymers such as: poly(butylene adipate-co-terephthalate) [32,33] poly(butylene succinate) [34,35], poly(hydroxy butyrate) [36,37], polyaniline with multiwalled carbon nanotubes as flexible free-standing electrode for supercapacitors [38];…”