Development of novel bio-based multi-component granulate additives for plastics

Formulating polymer compositions and producing polymer composites underpin the plastics processing sector. New functional characteristics often result not only from the physicochemical properties of fillers and additives and their effects on the matrix polymer's structure, but also from specific preparation procedures and mixing and shaping conditions for the final products. Often, achieving significant changes in the polymer's mechanical properties and structure requires introducing several additives with different physical states and geometric characteristics, which affects the polymer's bulk density. As a result, producing a material with a specific chemical composition from thermoplastic polymers requires an additional mixing step using extruders equipped with dosing systems to obtain semi-finished pellets that can be further shaped using various techniques. This requires an additional technological process in which the polymer is subjected to thermomechanical stress using dedicated equipment.

Furthermore, as environmental awareness grows, recycled materials and biodegradable polymers are increasingly being reintroduced into the production cycle, accounting for a larger share of the plastics processing sector. In both cases, it is vital to limit additional processing cycles. Economically, the goal is to reduce manufacturing costs and improve process profitability. Nevertheless, beyond costs, excessive processing can cause uncontrolled changes in polymer matrix properties due to process-induced degradation from exposure to an oxidizing atmosphere at elevated temperatures or, in the case of thermoplastic polyesters, hydrolytic degradation. Such an effect can be noted despite the use of stabilizers and adherence to temperature regimes.

Beyond cost and reduced plastic performance, additional melt-blending operations may affect the fillers and other additives introduced. Inappropriate incorporation methods can intensify simultaneous thermooxidative, thermal, thermomechanical, and hydrolytic degradation. To prevent degradation, all components must be properly dried, which typically requires separate devices for drying plastic pellets and additives because their particle-size distributions and densities differ, thereby limiting the use of, among other things, fluidized-bed dryers. Further, due to different physical properties of fillers and various additives, there is the need to introduce them into the polymer separately, implying the need to use multiple dosing devices simultaneously, each suited to the form of the additive being used, since devices designed for solids, liquids, and pastes differ in design and operating principles.

As a result, producing modified plastics or composites that meet increasingly stringent product requirements requires an extensive machine park and, consequently, large investments, limiting production to the largest companies. For small businesses without the necessary machinery to prepare multi-component formulations, outsourcing certain tasks lengthens the production chain. It increases the carbon footprint of the final products.

To address these drawbacks, a novel manufacturing concept is needed to simplify subsequent processes without compromising final product performance. To some extent, masterbatch production addresses this need. Masterbatches typically contain high concentrations of specific modifiers. They are introduced into a polymer matrix to achieve the desired additive loading and alter plastic performance. Nevertheless, the presence of a polymer phase may limit applications because of compatibility issues between the masterbatch pellets and the polymer matrix used to make them. Research indicates that even a small incompatible-phase loading may affect plastic performance. Moreover, although masterbatch production simplifies further processing, it involves melt-blending operations that, as mentioned above, may degrade polymer performance.

Here, we aim to eliminate these technological difficulties by introducing a method for producing multi-component additives as granulates without adding polymer, enabling their efficient introduction into conventional processing machines alongside plastic granulates. These multi-component granules, with particle-size characteristics similar to those of granules made from unmodified polymer, developed as a product family under the name granuQlki™, enable stable dosing after only mechanical mixing before introduction into dosing systems or combined drying-and-dosing systems.

The goal of the project is to develop novel material compositions addressing particular needs of polymer-based materials and extend the applicability of granuQlki™ solution.