Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - REFUCOAT (Full recyclable food package with enhanced gas barrier properties and new functionalities by the use of high performance coatings)

Teaser

- Problem:Barrier packaging is restricted by factors such as lack of biodegradation, recycling complexity and cost. Mechanical recycling also becomes a problem with multilayer structures containing more than one type of plastic or combination with other materials such as...

Summary

- Problem:
Barrier packaging is restricted by factors such as lack of biodegradation, recycling complexity and cost. Mechanical recycling also becomes a problem with multilayer structures containing more than one type of plastic or combination with other materials such as aluminium.
- Importance for society:
Replacing the oil-based packaging materials with bio-based ones might give a competitive advantage due to more sustainable and greener image, maintain properties. RefuCoat project aims to develop hybrid bio-based high oxygen/water barrier and active coatings to be used in a monolayer bio-based packages (films and trays) as alternative to current metallised and modified atmosphere (MAP) packages. Currently, both types of packages are based on the use of non-renewable materials in multilayer structures that lead to complex and expensive recycling steps.

- Overall objectives:

- 1: Microbiological modification of middle chain polyhydroxyalkanoates (PHA) to achieve a polymer with high water barrier. Target WVTR < 5
- 2: Production and purification of glycolic acid (GA) for reactive extrusion polymerization from mono ethylene glycol (MEG) using gold based catalysts. Target yield > 90% & purity >99%
- 3: Development of polyglycolic acid (PGA) low melting temperature based adhesives to be used in the hybrid coating formulations (Linked to WP3).
- 4: Development of biodegradable Organic–Inorganic Hybrid Coatings based on the combination of modified silica oxide and PGA as a real alternative to metallised coatings. Target OTR < 2 cc/m2/day and WVTR < 2 cc/m2/day
- 5: Incorporation of an active substance (antimicrobial and antioxidant) to the hybrid coating to enlarge the shelf life of selected foods. Shelf life target increase of selected food products up to 15% .
- 6: To produce new packages based on Bio-PET + hybrid and active coating with high water and oxygen barriers (OTR< 1 cc/m2/day and WVTR<1 g/m2/day)
- 7: To produce new packages based on Bio-PE + hybrid and active coating with high water and medium oxygen barriers (OTR< 5 cc/m2/day and WVTR<1 g/m2/day),
- 8: To produce new packages based on PHA middle chain + hybrid and active coating with high water and medium oxygen barriers (OTR< 5 cc/m2/day and WVTR<1 g/m2/day)
- 9: To demonstrate the safety & regulatory compliance, as well as environmental & economic sustainability of the developed processes and products (linked to WP6).
- 10: To maximize the innovation impacts of the project for contributing to the uptake of the project results for companies’ business and employment growth

Work performed

During first 18M of the project, the requirements and selection of raw materials were defined (WP1) taking into account end-users requirements as well as project objectives. With this information, in WP2, an efficient, green and robust chemocatalytic process using gold-based catalysts for the production of GA and an isolation and purification protocol has been developed for the GA, and mcl-PHA with different monomer composition has been produced. In WP3, FRAUNHOFER has produced and sent to AIMPLAS PGA. The low solubility of the PGA is a challenge. Further tests are going to be developed by FRAUNHOFER and AIMPLAS in order to improve its processability for the final hybrid coating formulation. At the same time, active(antimicrobial/antioxidant) coatings are being studied and developed (WP4) by AINIA and IRIS. Also, bacteriophages in different matrices were also evaluated and showed a promising results for being applied as antimicrobial in active packaging. Further work needs to be done. In relation with the fabrication of packages, coating application an full characterization (WP5), initial activities have been carried out by AIMPLAS and MI-PLAST.

Final results

a) Progress in the field of mcl-PHA
An efficient fermentation process is being developed for the production of modified mcl-PHA. Using starch rich residues from DACSA, different production pathways of selected Pseudomonas and other bacterias strains are exploited, through β-oxidation pathway through the manipulation of genes to obtain higher hydrophobicity in the mcl-PHA. The PHA monomer composition modulation procedure according to a desired final application properties still being a novelty solution for polymer design.
By the other hand the improvement of PHAs properties for packaging can be optimised by blending them with other polymers or additives. In order to increase market feasibility, low cost renewable feedstock such as starch rich residues from DACSA production process will be employed.

b) Progress in the field of hybrid coating
The combination of organic polymer and inorganic material in a single phase provides exceptional possibilities to tailor properties for different applications. There are a wide range of companies focusing in sol-gel technology for the of production functional coating based on sol-gel approach for different applications. A sol-gel approach for obtaining an inorganic-organic hybrid coating PGA/micro size Si-SiO2 still being a challenge for most biodegradable polymer. REFUCOAT has being able to formulate PGA hybrid coating based on hydrogen bonds.

c) Progress in the field of PGA
Within Refucoat a continuous solvent-free method for PGA polymerization was developed using the polycondensation route. Polycondensation is seen as a possible way to produce PGA in a one-step-synthesis. Using this method compared to solvent-based batch processes not only saves potentially costly and/or hazardous solvents but also ensures minimal process steps and therefore less thermal stress on the product. The processing knowledge about PGA polycondensation can potentially be used for other polycondensation reactions to transfer their synthesis from batch to continuous as well.

d) Progress in the field of PGA hybrid coating
The combination of organic polymer and inorganic material in a single phase provides exceptional possibilities to tailor properties for different applications. There are a wide range of companies focusing in sol-gel technology for the of production functional coating based on sol-gel approach for different applications. By the other hand Biodegradable polymers like PGA have a great potential and widely used in biomedical applications due to their biodegradability and biocompatibility, however, limited research based on PGA polymers has been studied for other applications due to insolubility of PGA in most of the solvents and rapid degradation of PGA. A sol-gel approach for obtaining an inorganic-organic hybrid coating PGA/micro size Si-SiO2 still being a challenge for most biodegradable polymer. REFUCOAT has being able to formulate PGA hybrid coating based on hydrogen bonds.

e) Progress in the field of active coating
In this project, there are two very novel approaches on active coating:
• introducing bacteriophages in the packaging technology is proposed, with the expected result of reducing foodborne illness by actively inhibiting target microorganisms providing an additional inactivation process beyond the end of the production process.
• hybrid coating with barrier and active properties by including antioxidant compounds that will be tailored to the application on different substrates and validated for different food products such as potato chips and bread crumbs.

Website & more info

More info: https://www.refucoat.eu.