Polyethylene Furanoate (PEF) as a Renewable Bioplastic

TAGS:  Sustainability and Bioplastics    

Bioplastics are a key sustainable element of the 21^st century. They balance environmental benefits and impact.

Polyethylene furanoate (PEF) is a popular bio-based polymer. This next-generation material can replace oil-based polymers.

PEF is renewable, non-toxic, and recyclable. It has similar properties to traditional plastics. However, efficient commercial production of PEF requires consideration.

Get more information about:

• The chemical structure of PEF
• Can PEF Replace PET?
• Closing-the-loop - Steps in PEF recycling process
• Scaling up of PEF from lab to market
• Key applications of PEF

The Chemical Structure of Polyethylene Furanoate (PEF)

Polyethylene furanoate (PEF) is a 100% recyclable, bio-based polymer. It is made from renewable plant sugars. PEF production polymerizes furan dicarboxylic acid and ethylene glycol. The process resembles PET production. But PEF substitutes terephthalic acid with 2,5 furan dicarboxylic acid (FDCA).

Furanic family: The sleeping giants of intermediate chemicals

5-hydroxymethylfurfural (5-HMF), 2,5-furandicarboxylic acid (FDCA), and 2,5-dimethylfuran (2,5-DMF) are the main representatives of the furan family. Furans have enormous potential as renewable intermediate chemicals. This has led to them being called “sleeping giants" of renewable intermediate chemicals.

C6 sugars (carbohydrates) are excellent sources for producing furanic monomers. HMF and FDCA show high potential as precursors for PEF.


FDCA (C₆H₆O₃; MW = 126.11) is a bio-based building block for resins and polymers. It is used to produce high-value products including:

• Polyesters
• Polyamides
• Copolymers
• Solvents
• Coating resins and plasticizers

FDCA forms by the oxidative dehydration of hexose. It can also form by oxidizing 5-hydroxymethylfurfural (HMF).

FDCA has the potential to replace terephthalic acid (PTA). PTA is a widely used synthetic component for polyesters like polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

FDCA produces a new polymer class called PEF. PEF shows great potential for bio-based plastic bottles.

Methods to produce FDCA

Some methods to produce FDCA are:

1. Dehydrating of hexose derivatives

2. Oxidizing of 2,5-disubstituted furans

3. Catalytic conversion of furan derivatives

FDCA has many derivatives from simple chemical transformations. Selective reduction leads to:

• Partially hydrogenated 2,5-dihydroxymethylfuran
• Fully hydrogenated 2,5-bis(hydroxymethyl) tetrahydrofuran

These can be new polyester alcohol components. Combined with FDCA, this allows new biomass-derived products.

Barriers of FDCA production

➤ High process cost
➤ Limited by intermediate 5-HMF availability
➤ Need effective, selective sugar dehydration processes - Could enable more building blocks. But current processes are non-selective unless unstable intermediates quickly become stable
➤ Requires developing selective systems and catalysts
➤ Must understand and control FDCA esterification reactions and polymer properties. This is vital for commercial success


FEATURED PRODUCT

Can PEF Replace PET?

PEF is the next-gen polyester. It has potential to replace polyethylene terephthalate (PET) - a durable fossil fuel-based polymer.

PEF vs. PET — Outperforming across key properties

Compared to PET, PEF offers benefits. Notable PEF properties include:

• Biodegradability — PEF biodegrades under industrial composting. It breaks down much faster than plastics like PET.


• Gas barrier properties — PEF has better gas barrier than PET. This makes PEF suitable to package carbonated drinks. Preventing gas escape is important.


• Mechanical properties — PEF has excellent oxygen barrier and good mechanical properties. Its tensile strength exceeds PET while rigidity is similar. This enables thinner, material saving PEF bottles.


• Thermal properties — PEF withstands higher temperatures. It has a higher glass transition temperature, modulus and melting point versus PET.


• Renewability — PEF uses renewable plant sugars. PET uses fossil fuels. This gives PEF sustainability benefits. FDCA-based PEF is 100% biobased when using biobased MEG.


• Recyclability — PEF is theoretically recyclable, though infrastructure needs development. The goal is to integrate PEF recycling into existing PET recycling.

PEF vs. Existing Packaging Materials (Source: Avantium)
PEF permits greater light weighting and superior thermal stability without heat-setting (can be hot filled at about 200°F). PEF needs fewer additives than PET for formation. Currently, PEF costs slightly more. However, as scale increases, PEF costs should reach parity or better with PET.

PEF vs. PET – Comparing the values 

Property		PEF vs. PET		Benefit
Barrier*	O2	6 - 10 x	1 x	Increased shelf life Avoid barrier layers
	CO2	4 - 6 x	1 x	Increased shelf life Avoid barrier layers
	H2O	2 x	1 x	Better performance in humid areas
Mechanical	Tensile modulus	~ 1.6 x	1 x	For rigid bottles Increased top loads
Thermal	Tg (°C)	86 - 87	74 - 79	For hot filling of nutritious drinks
	Tm (°C)	213 - 235	234 - 265	Co-extrusion possibilities
* measured and validated in several inhouse research projects as of 2014

PEF vs. PET - Comparision of Properties (Source: Corbion)

Closing the Loop: Recycling and Its Positive Impact

Products made of PEF can easily be recycled or converted back to atmospheric CO₂ by incineration. Eventually, that CO₂ will be taken up by grass, weeds, and other plants, which can then be used to make more PEF.

PEF recycling is similar to PET recycling. It can be recycled and incorporated into the PET recycling streams at up to 5% PEF. It has no effect on the recycled PET performance.

• PEF can be separated from PET by IR sorting and recycled to ‘rPEF’ using the same steps as PET (mechanical or chemical recycling using the same steps as PET).
• PEF has significantly less impact on rPET than Nylon or PLA.

PEF reduces the need for multi-material functionality in packaging. However, there are still some steps to be taken in packaging re-design and waste management.

From waste to innovation: Steps for PEF recycling

Collection and sorting
PEF bottles, packaging, and other products are collected and sorted from post-consumer waste streams. This separation from other plastic types is important to obtain pure PEF waste.


Shredding and cleaning
The PEF material is shredded into smaller flakes/chips and thoroughly cleaned to remove impurities.


Extrusion
The flakes are dried and fed into an extruder system to be melted and extruded into pellets or granules. This converts the waste into a format usable for remanufacturing. View in-depth guide on extrusion process.


Solid state polymerization (SSP)
The pellets undergo solid-state polymerization. This boosts their molecular weight and intrinsic viscosity, restoring mechanical properties.


Re-granulation
After SSP, the polymer pellets are re-granulated into smaller and more uniform sizes to prepare them as feedstock.


Product remanufacturing
The recycled PEF granules are finally used like virgin PEF resin. This helps to fabricate new bottles, sheets, and films via processes like injection molding and blow molding. They can be blended with some virgin PEF to tailor properties.

Growth Prospects of PEF: Lab to Market

The utility of FDCA as a PET/PBT analog offers an opportunity to address a high-volume, high-value chemical market. To achieve this opportunity, R&D to develop selective oxidation and dehydration technology is being carried out.

2,5-furandicarboxylic acid (FDCA) is an important chemical intermediate for PEF production. Several chemical companies are currently working on manufacturing it.

• AVA-CO₂ offers a patented conversion process of 5-HMF to FDCA
• Wageningen UR has successfully prepared FDCA semi-aromatic polyesters
• Avantium, along with BASF is working towards making FDCA and PEF a commercial reality
• Corbion is also working on the manufacture of FDCA for PEF
• ETH Zurich develops a new method that could finally make the PEF marketable

Out of these Synvina (BASF + Avantium JV) and Corbion are focusing their energies on FDCA for PEF. Corbion has developed a propriety process to produce FDCA and is currently working with dedicated partners to further develop and commercialize it.


Source: Corbion
Avantium developed and patented the YXY technology platform. This is aimed at manufacturing biofuels, bio-based plastics, and biochemicals. The JV between Avantium and BASF established a strategic partnership with Danone, Coca-Cola, and ALPLA. This is for developing and commercializing bio-based polymers derived from PEF. Later on BASF exited from this JV in January 2019.


In 2014, Avantium, Danone, Swire Pacific, and Coca-Cola signed a consortium of USD 50 million in investments. It is aimed at developing and commercializing the alternative to PET for packaging applications. In 2014, Avantium demonstrated the application of PEF for the manufacturing of fibers to make 100% bio-based t-shirts for textile manufacturers.

The Coca Cola company, Danone, ALPLA partner for the development of 100% bio-based PEF bottles. Wifag-polytype for PEF thermoformed products and other partnerships in various stages for PEF fibers, films, etc. However, commercial production and launch of FDCA and PEF is expected to be operation by 2024.


PEF - Plant-based Plastics for a Circular Future (Source: Avantium)
Another breakthrough research is reported by ETH Zurich researchers. It reveals a new method that could enable the commercial breakthrough of PEF. In their study, instead of making the usual "rope-like" polymer chains with two endpoints react, researchers first tie rings from the latter. Thus, they have no ends anymore. These rings can then be polymerized to PEF in a controlled manner.

The new method leads to no chemical by-product production when the rings are opened and connected to form the final long "polymer rope". The new method is claimed to reduce:

• production time from several days to a few hours
• energy requirements

Scientists are now further working with Suzler to investigate how the new process could be implemented in industrial mass production.

PEF Adding to New Application Frontier

PEF’s excellent barrier properties and calculated cost price show that it can compete with packaging products. This includes aluminum cans, multilayer packaging, and small-size multilayer PET bottles. They compete on price and performance when produced at a large scale. PEF offers unique opportunities in packaging that enables:

• safe and recyclable small-size rigid packaging
• simplicity and renewability to flexible packaging

There are several applications where PEF is commonly used are:

1. PEF bottles — Water bottles, beverage bottles, etc. The polymer completely meets the growing trends in packaging like sustainability and cost reduction. It is a 100% biobased, fully transparent, and recyclable alternative to PET. PEF is lightweight, thermally, stable, and transparent that offers prolonged shelf life in bottles.


2. PEF films — It opens new opportunities in flexible packaging. As compared to BOPET-based packaging, PEF has equal thermo-mechanical and surface properties. Even SiOx/AlOx coated or metalized BOPEF can offer a superior barrier to conventional substrate films. PEF films are recyclable with suitable other layers or compatible with clean energy recovery at reduced GHG emissions.


3. PEF fibers — The main applications include apparel, carpets, home furnishing, disposables commodities, fabrics, diapers, filters, and industrial fibers.

Are you looking for the latest industry updates on PEF? Find all updates here »