Gas permeability, mechanical behaviour and compostability of fully-aliphatic bio-based multiblock poly(ester urethane)s

Abstract

A family of poly(ester urethane)s obtained by chain extending hydroxyl-terminated polyester prepolymers has been studied. Poly(butylene cyclohexanedicarboxylate) has been coupled in different mass ratios with two poly(butylene succinate)-based random copolymers containing ether linkages. So, five high molecular weight bio-based poly(ester urethane)s have been designed. The effect of the chemical structure and of the mass ratio of the two blocks in the final polymer has been evaluated by characterizing the materials from a molecular, thermal and mechanical point of view. In addition, envisioning a food packaging application, biodegradation in compost and measurement of the gas barrier properties have been carried out and correlated to the polymer chemical structure. The activation energy of the gas permeation process has been calculated, too. The results highlight that through the adopted strategy it is possible to prepare a new class of promising materials whose properties can be easily tailored by acting on two parameters: the mass ratio between the two prepolymers in the final material and the chemical structure of each block.

Recent Advances in Nanocomposites Based on Aliphatic Polyesters: Design, Synthesis, and Applications in Regenerative Medicine

“…In this view, the use of chain extenders may help overcome these limitations. For the preparation of APs, the coupling of diisocyanates with hydroxyl-terminated polyesters has been investigated [53][54][55][56]. Through this technique, it is possible to obtain high molar mass poly(ester urethane)s (PEU) showing optimized functional properties for the intended application.…”

“…In addition, two main pathways can be explored leading to different molecular architectures. On the one hand, by combining two or more OH-terminated (co)polyesters obtained by polycondensation, random multiblock structures will be achieved [53][54][55] (Figure 2A). On the other hand, by exploiting the hydroxyl terminal groups of a (co)polyester for the ring opening reaction of a lactone, triblock copolymers can be easily prepared ( Figure 2B).…”

“…The reactive blending strategy permitted to overcome this limitation, already for short reaction times, i.e., long copolymeric sequences, as a single T g was observed [19,50,51]. The chain extension of hydroxyl-terminated prepolymers, which led to the formation of multiblock copolymers, also evidenced a complete miscibility of the final materials in the amorphous phase [53][54][55]. As to the melting process, DSC traces of APs may show multiple melting peaks that have been imputed to melt-recrystallization phenomena that take place during the DSC scan [13].…”

Temperature dependency of gas barrier properties of biodegradable PP/PLA/nanoclay films: Experimental analyses with a molecular dynamics simulation approach

“…This means that they ought to have low O 2 and high CO 2 permeability . Petroleum‐based conventional plastics like polyethylene, polypropylene (PP), ethylene‐vinyl acetate, polystyrene, poly(vinyl chloride), and polyamide are commercially used materials in packaging industry . Nevertheless, environmental conservations have restricted their usage since they have low degradability in terrestrial ecosystems and increasing amounts of packaging plastics are buried in landfill sites each year …”

“…[1][2][3] Petroleum-based conventional plastics like polyethylene, polypropylene (PP), ethylene-vinyl acetate, polystyrene, poly(vinyl chloride), and polyamide are commercially used materials in packaging industry. [4][5][6] Nevertheless, environmental conservations have restricted their usage since they have low degradability in terrestrial ecosystems and increasing amounts of packaging plastics are buried in landfill sites each year. 7 In this regard, scientists have focused on using biodegradable polymers such as poly(lactic acid) (PLA) and starch.…”