Commercial Marine-Degradable Polymers for Flexible Packaging

Abstract

Summary Plastic pollution is entering the world's oceans at alarming rates and is expected to outweigh fish populations by 2050. This plastic waste originates from land-based applications, like consumer product packaging, and is composed of high-durability polyolefins. These conventional plastics possess desirable properties, including high chemical stability, moisture barrier, and thermoplastic characteristics. Unfortunately, if these materials reach marine environments, they fragment into microplastics that cannot be biologically assimilated. The aim of this review is to investigate commercial polymers that are biodegradable in marine environments but have comparable product stability and moisture barrier properties to polyolefins. Among commercially available biopolymers, thermoplastic starches (TPS) and polyhydroxyalkanoates (PHAs) have been shown to biodegrade in marine environments. Moreover, these biopolymers are thermoplastics and possess similar thermoforming properties to polyolefins. At present, TPS and PHAs have limitations, including chemical instability, limited moisture barrier properties, and high production costs. To replace conventional polymers with PHAs and TPS, these properties must be improved.

Synthesis, Properties, and Enzymatic Hydrolysis of Poly(lactic acid)-co-Poly(propylene adipate) Block Copolymers Prepared by Reactive Extrusion

“…To fully transition to a sustainable future, the radical transformation of the plastics market towards biobased and biodegradable polymers is necessary [ 6 ]. Many biobased and/or biodegradable plastics with a wide variety of properties have been reported on a research level [ 7 , 8 ], and some are being produced on a commercial scale [ 9 , 10 ]. Among them, poly(lactic acid) (PLA), a biobased, biocompatible, and compostable aliphatic polyester is one of the most produced and used biobased plastics in the world [ 11 ].…”

Effect of Mineral Fillers on the Mechanical Properties of Commercially Available Biodegradable Polymers

“…Other biodegradable polymers such as PBS and PBSA show biodegradation rates in soil environments that are several orders of magnitude higher than that of PE-, PP-, and PET-based plastics, although they are typically not certified as such since the timeframe does not always match the certification standards [ 6 ]. In this respect, PHA and PBAT polymers are amongst the few polymers that are (certified) biodegradable in all environments including marine conditions and therefore, show much potential for use in high littering risk applications [ 7 , 8 ]. The ability to process these biodegradable polymers in complex shapes required for products such as bags, containers, and toys is most often comparable to that of non-biodegradable plastics.…”

“…The ability to process these biodegradable polymers in complex shapes required for products such as bags, containers, and toys is most often comparable to that of non-biodegradable plastics. However, a clear disadvantage is that the number of biodegradable polymers that possess both the stiffness and impact resistance that are required for these applications is limited [ 7 , 9 ]. This is one of the reasons that these biodegradable polymers are often not seen as acceptable alternatives for conventional non-biodegradable plastics.…”

Biosynthesis of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from CO2 by a Recombinant Cupriavidusnecator

“…Plastic wastes reaching marine environments fragmented into microplastics, but they cannot be biologically assimilated, and, unfortunately, many biodegradable plastics are also not decomposed in marine environments [ 1 ]. In contrast, bacterial polyhydroxyalkanoates (PHAs) have been shown to be biodegraded in marine environments [ 2 ]; thus, they are attracted as eco-friendly biodegradable plastics that are alternatives to petrochemical-derived plastics. More than 150 kinds of hydroxyalkanoate units have been identified as constituents of PHAs [ 3 ].…”