allnex: Sustainable Resins from Recycled Sources

allnex Composites in Australia is a leading producer of Unsaturated Polyesters, Gelcoats and Vinyl Esters for a wide range of Composite applications. It recently launched a transformative polyester resin—POLYPLEX® 200E—that incorporates recycled PET (rPET) sourced from post-consumer plastic bottles. This resin is a major stride toward more sustainable composite applications, particularly in structural contexts such as swimming pools and marine use.  Produced in Australia, each drum contains the equivalent of approximately 750 bottles, or 3.3 bottles per kg, and the company’s goal is to process at least 100 metric tonnes per year. This not only diverts waste from landfill but also reduces reliance on petroleum‑derived feedstocks—key drivers in adopting circular materials.

Why rPET Matters

PET is one of the most recycled plastics worldwide, initially developed in the 1940s and widely used today in bottles, films, and fibers. However, reincorporating rPET into new resin, allnex both reduces plastic waste and supports customer sustainability goals. Recycling PET also  dramatically reduces energy consumption (by as much as 70 %) and greenhouse gas emissions (up to 60–79 %) compared to virgin PET production. Life‑cycle assessments suggest that rPET has a carbon footprint around 0.45 kg CO₂ per kg, versus about 2.5 kg CO₂ per kg for virgin PET.

Circularity and eco‑friendly materials are increasingly valued by industry. Incorporating rPET strengthens brand reputation while meeting eco-pledges.

Technical Challenges in Using rPET

Creating a performance-grade resin with recycled material wasn’t straightforward. Bottles vary in polymer grade, dyes, additives, labels and adhesives. Ineffective separation can cause contamination, phase separation, yellowing and compromised mechanical strength. Thermal processing and washing can also break PET chains, lowering viscosity and molecular weight—adversely affecting processability.

Contaminants such as trace PVC, adhesives, solvents, labels, detergents or water can affect polymer integrity, requiring extensive cleaning and filtration. Impurities and dyes can affect colour and clarity, which can lead to yellowing; oxidised rPET may have unacceptable optical or aesthetic qualities. 

allnex uses stabilisers and chain‑builders and fine‑tunes processes like solid‑state polymerisation to restore intrinsic viscosity and improve heat stability. They also monitor CTI (Circular Transition Indicators) to chart performance and guide material optimisation.

Performance vs Virgin PET

Mechanical & Chemical Properties

With careful design, rPET‑based resins like POLYPLEX 200E demonstrate improved mechanical properties and water resistance, outperforming standard ortho‑phthalic resins—ideal for challenging applications like swimming pools.

Processing Behaviour

POLYPLEX 200E maintains workability similar to virgin counterparts, ensuring ease of use. Likewise, allnex’s CRYLCOAT® OCEAN powder‑coating resins, with up to 25 % rPET, cure at standard temperatures (~160 °C) and match traditional resins in flow, gloss and weather durability. These resins maintain colour stability, chemical resistance, and gloss retention—even under accelerated weathering tests. This counters earlier concerns that rPET might compromise appearance or coating performance.

Balancing Sustainability and Quality

While virgin PET still offers the gold standard for clarity, barrier performance, and consistent properties in top‑tier food and packaging applications, innovations in rPET—advanced sorting, stabilisers, and polymer rebuilders—are steadily closing the gap.  However, rPET processing often involves higher costs due to sorting, energy-intensive cleaning, filtration systems, and regulatory compliance. Still, this additional cost may be offset by environmental benefits, brand value, and regulatory incentives. Sometimes, rPET can even be cheaper than virgin PET, depending on market dynamics.

allnex’s Innovations: Real‑World Applications

• POLYPLEX® 200E is being produced in Australia today for structural composites like pool laminates—consuming 100 MT of PET annually and boosting mechanical and water‑resistance performance. 
• CRYLCOAT® OCEAN series applies rPET to powder coatings (up to 50% in some grades), reducing production carbon footprint by 20% while maintaining functionality across environments.

A Sustainable Gateway for Polymer Science

allnex’s rPET‑enhanced resins are leading examples of the materials‑science transition toward truly circular performance polymers. By:

• integrating recycled plastic feedstocks,
• quantifying circularity via CTI assessments,
• and pioneering additives and processes that preserve quality, they provide a blueprint for embedding sustainability into resin chemistry.

This work paves the way for the broader adoption of rPET in industrial coatings, composites, structural applications, and beyond. As recycling technologies (mechanical, chemical, enzymatic) improve, the barrier between rPET and virgin PET continues to blur—and the potential for a low-carbon, closed-loop polymer economy becomes increasingly real.

Conclusion

allnex’s new rPET‑based resins—POLYPLEX 200E and CRYLCOAT OCEAN—demonstrate that sustainability and performance can coexist. By overcoming technical challenges through smart feedstock management, stabilisers, quality control, and circularity metrics, allnex proves that recycled raw materials can underpin high‑performance polymer solutions.

While virgin PET retains a role in premium, high‑clarity applications, advances in recycling methods and polymer science are narrowing the gap—enabling recycled PET resins to lead the charge in sustainable materials innovation.

The transition to rPET‑enhanced polymers is not just a vision—it’s happening now, and it’s reshaping the materials landscape for a more sustainable future.