Polymer chemists at US-based Colorado State University (Fort Collins, Colorado; www.colostate.edu) say they have created a synthetic polyhydroxyalkanoates (PHA) platform that paves the way for the materials to take off in the marketplace as truly sustainable plastics.

Led by professor Eugene Chen, the research team sought a strategy to address the intrinsic thermal instability of conventional PHAs. The materials’ lack of heat resistance also makes it difficult to melt-process them into end products. The chemists are said to have made fundamental changes to the structures of these plastics, substituting reactive hydrogen atoms responsible for thermal degradation with more robust methyl groups.

This structural modification reportedly drastically enhances the PHAs’ thermal stability, resulting in plastics that can be melt-processed without decomposition.

What’s more, researchers say newly designed PHAs are mechanically tough, even outperforming the two most common commodity plastics: high-density polyethylene – used in products like milk and shampoo bottles – and isotactic propylene, which is used to make automotive parts and synthetic fibres.

According to the chemists, the PHA can be chemically recycled back to its building-block molecule, called a monomer, with a simple catalyst and heat, and the recovered clean monomer can be re-used to reproduce the same PHA again ­– in principle, infinitely.

LG Chem (Seoul; www.lgchem.com) and US-based Gevo (Engelewood, Colorado; www.gevo.com) say they will jointly develop a technology that creates 100% bio-based plastics from renewable sources of carbohydrates such as corn. The companies reported that they expect to produce bio-propylene with bio-ethanol produced from carbohydrates including corn and sugarcane.

Gevo is to provide LG Chem with its Ethanol-to-Olefins (ETO) technology, which uses ethanol as feedstock for the production of propylene. LG Chem, in turn, is to verify and advance the technology through technical scale-up, pilot research, and commercialisation.

Kuraray (Tokyo; www.kuraray.com) said it has launched its Eval brand bio-circular and recyclable ethylene-vinyl alcohol (EVOH) what protects against oxygen-induced degradation in food to a product’s shelf life and quality.

Eval with metallisation is also suitable for substances classified as active pharmaceutical ingredients (API), the company said, making the resin ideal for packaging sensitive content such as medicines.

Eval has a thickness of only 1 mm but offers the same gas barrier as a 10-meter-thick wall of LDPE, according to the supplier. The ISCC PLUS certificate Kuraray has received is said to cover all EVOH variants that Kuraray produces in Antwerp.

Kuraray America has announced a new grade for its Plantic portfolio called Plantic EP, a plant-based resin designed specifically for extrusion coating. It can be used to develop sustainable gas and aroma-barrier solutions with paper, paperboard, or traditional film substrates. The company said the grade recently passed repulping and recyclability certification from US-based Western Michigan University (WMU, Kalamazoo, Michigan; www.wmich.edu), laying the groundwork for sustainable barrier pouch and carton formats for brand owners and converters. The supplier added that the market now has a high-barrier option that can be fully recoverable and recyclable in the US paper stream.

Biopolymer grade target hygiene applications US polylactic acid (PLA) biopolymer supplier NatureWorks (Minneapolis, Minnesota; www.natureworksllc.com) said it has expanded its Ingeo family of biopolymers with Ingeo 6500D for non-wovens.

When combined with tailored topical treatments developed with US fibre lubricant specialist Goulston Technologies (Monroe, North Carolina; www.goulston.com), the new grade is said to produce lighter and thinner absorbent hygiene products that offer improved fluid management and breathability for better skin health.

The supplier said the grade’s inherent hydrophilic properties result in non-wovens that require less surface finish and have better durability compared to polypropylene. Significant improvements are also seen in both the soak surface tension results and the multiple strike performance, according to the company.

NatureWorks said it hosted a cornerstone laying ceremony on 1 February 2023 at its new Ingeo manufacturing facility located at the in Nakhon Sawan Biocomplex (NBC) in Thailand. The plant is expected to be completed in the second half of 2024 and feature a capacity of 75,000 t/y. Output from the facility is expected to support biopolymer growth in markets such as 3D printing, hygiene, compostable coffee capsules, tea bags, flexible packaging, and food service ware.

WinCup (Stone Mountain, Georgia; www.wincup.com) says its “phade” paper cups are lined with PHA, a biopolymerderived from the fermentation of canola oil. Phade is said to be marine biodegradable and home and industrial compostable, making it an alternative to traditional paper cups that are coated in fossil fuel-based plastic.

Lapp (Stuttgart, Germany; www.lapp.com) has announced the introduction of the first ethernet cable with a bio-based sheathing. It said Etherline FD P Cat.5e used for industrial ethernet is now also available as a more sustainable version thanks to the bio-based TPU developed by BASF (Ludwigshafen, Germany; www.basf.com).

The bio-based plastic Elastollan N, a thermoplastic polyurethane from BASF, is said to be a corn-based biopolymer. Depending on the type of TPU, the proportion of renewable raw materials is 45-60%. The TPU reportedly offers the same durability, flexibility, and mechanical properties as well as the hydrolysis, chemical, and UV resistance as conventional Elastollan, and even processability parameters have been retained.

A special feature is that the proportion of biomaterial in the finished product can actually not only be detected but also precisely measured (according to ASTM D 6866). It is ideal for patch cable applications and also for cable chains, according to the report.

A research team based at Inha University (Incheon, South Korea; www.eng.inha.ac.kr) said it has developed a biodegradable straw that doesn’t get soggy and is stronger than plastic. The straw is made of a new type of bioplastic film from all-natural, degradable materials, according to a research paper published by the American Chemical Society’s scientific journal ACS Omega (www.pubs.acs.org).

The paper said researchers blended lignin with either potato starch or polyvinyl alcohol, a more traditional bioplastic material, before adding citric acid. They spread the slurry into a thin layer, rolled it into a cylinder, and cured it at over 350F (177C). The bioplastic naturally self-adhered at the seam, but heat treatment set it and made it even stronger, the report said.

US-based firms Lummus Technology (Houston, Texas; www.lummustechology.com) and RWDC Industries (Athens, Georgia; www.rwdc-industries.com) have announced that they recently signed a memorandum of understanding to cooperate on global PHA deployment initiatives. The agreement is said to be a key step aimed at rapidly growing the manufacturing of PHA through global licensing opportunities.

With Lummus’s expertise in process technology and RWDC’s expertise in PHA production and application, the partnership said it expects to significantly accelerate global availability and mass adoption of this natural alternative to synthetically produced petroleum-based plastics.

RWDC uses plant-based oils, including post-consumer or waste cooking oils, to produce its proprietary Solon-brand PHA.

Lummus and compatriot firm Citroniq Chemicals (Houston, Texas; www.citroniq.com) said they have signed a letter of intent for the development of Citroniq’s green polypropylene projects in North America. Citroniq expects to invest over USD 5 bn (EUR 4.54 bn) to build 3.5 bn pounds (nearly 1.6 mn t/y) in annual bio-PP capacity, with the first plant in the US scheduled to start production in 2026.

The projects plant to use Lummus’s Verdene PP technology suite. The goal is to create the first world-scale sustainable bio-PP production process in North America, with the first plant targeting to sequester about 1.2 mn t/y.