Researchers use corn distillers grains to boost performance of PU foam

A team of materials scientists has demonstrated that incorporating corn distillers grains – a by-product of ethanol production – into PU foams can improve mechanical durability and thermal stability, while advancing sustainability. The work was led by Przemysław Bartczak and colleagues at Poznan University of Technology, Poland.

The researchers suggest that, with increasing pressure to reduce dependence on petroleum-derived inputs and minimize waste, the reuse of agricultural residues such as distillers grains offers a compelling route toward more circular, lower-impact materials. Distillers grains, which consist primarily of protein, fiber, and carbohydrates, are often an underused by-product in ethanol production.

In their experiments, the team varied processing parameters – including particle size distribution, moisture content, and mixing temperature – to identify optimal formulations. They found that, under the right conditions, adding a controlled fraction of distillers grains improved compressive strength of the foam, an important performance metric for structural or load-bearing applications. The modified foams also showed enhanced thermal stability compared with conventional PU foams.

These dual benefits – mechanical reinforcement plus thermal performance – make the approach promising for sectors such as construction insulation, automotive parts, and furniture, where PU foams must maintain integrity under stress and temperature cycles.

A further advantage is cost: distillers grains are a relatively low-cost agricultural by-product, so their incorporation may help reduce raw material expenses for manufacturers, especially when the performance tradeoffs are modest. Also, using such by-products supports the shift toward circular economy practices, reducing waste streams and reliance on virgin feedstocks.
However, the authors caution that certain challenges remain. Compatibility between the bio-based fillers and PU matrix must be carefully managed to avoid negative effects (such as poor dispersion or phase separation). Moisture content and processing conditions require tight control, or else the benefits may be compromised. Scale-up of the method and industrial adoption will also depend on supply logistics, regulatory acceptability, and proof of long-term durability.

By demonstrating that a relatively inexpensive by-product can be harnessed to improve, rather than degrade, PU foam performance, Bartczak and team provide a practical model for how sustainability and performance goals might align in future materials development.

The research is published in the journal Waste and Biomass Valorization (2025) under the title Valorization of Agricultural By-Products in Polyurethane Foams: The Role of Corn Distillers Grains in Enhancing Material Properties.