Nouryon is a global leader in the radical initiator industry, which is essential for the production of thermoplastic polymers such as PVC, LDPE, acrylates, and styrene.
Our organic peroxides are also used to modify thermoplastics via reaction extrusion; the choice of peroxide depends on the type of polymer, the desired reaction, and the extrusion temperature.
Controlled-Rheology PP (CR-PP)
Polypropylene produced using Ziegler-Natta catalysts typically has a broad molecular weight distribution (MWD). This results in high melt elasticity, making it difficult to process on high-speed machines. Adding specific organic peroxides to the extruder effectively addresses this issue by inducing controlled degradation of the polymer.Organic peroxides narrow the molecular weight distribution while simultaneously reducing the average molecular weight. The decrease in melt viscosity and the increase in MFI can be controlled by adjusting the amount of peroxide added. Application areas include: PP film, extrusion coating, fibers (textiles, melt-blown), and injection molding.
We offer the world’s widest range of organic peroxides for polymer modification, including the latest-generation Trigonox® 301 for CR-PP production. As a patented product of AkzoNobel, it offers numerous advantages in polymer modification applications.Trigonox 301 is more cost-effective, and the volatiles generated by its decomposition products result in low-odor end products; Trigonox 301 has also been approved by the BfR (maximum addition level of 0.25%) and the FDA (maximum addition level of 0.375%) for use in the production of food-contact products.
High Melt Strength PP (HMS-PP)
The linear structure of polypropylene results in low melt strength and a lack of mechanical strain hardening properties, which can cause problems in melt extrusion applications. Potential issues include a narrow processing window, uneven cell size, and pinholes in thermoformed sheets.Nouryon has developed a patented technology to overcome these issues. By reacting a specific class of organic peroxides (perdicarbonates) with PP powder in an extruder, long side chains are introduced, increasing the melt strength of the polypropylene to produce high-melt-strength polypropylene (HMS-PP).HMS-PP exhibits a lower melt flow index; the introduction of long side chains broadens the molecular weight distribution, increases melt strength and die expansion, and improves mechanical strain hardening and melt elasticity. This makes PP foaming, thermoforming, and blow molding
possible.
The preferred peroxydicarbonate is Perkadox® 24L. It achieves the best results when blended in an extruder with PP (powder or pellets) produced in a reactor or with pre-ground PP pellets. Its decomposition products consist solely of carbon dioxide and hexadecanol, posing no odor issues for the final product.Perkadox 24L has received FDA food contact certification (maximum 2.0%) for all HMS-PP applications, including microwave-safe food trays.
Maleic Anhydride-Grafted Polyolefins
During the extrusion process, maleic anhydride can be grafted onto polymers such as polyethylene, polypropylene, and EPDM rubber using special organic peroxides. When organic peroxides and maleic anhydride are added separately, the choice of peroxide depends on its solubility in the polymer and the extrusion temperature used.Nouryon offers a variety of organic peroxides suitable for this separate addition process. Our latest product, Perkadox PFDBM25, incorporates maleic anhydride directly into the peroxide molecule.
This grafting technology developed by Nouryon improves the compatibility (solubility) between the grafting agent and the polymer, thereby preventing the presence of free maleic anhydride in the end product.Polymers grafted with maleic anhydride can be used in glass-fiber-reinforced polypropylene (GFR-PP) and interlayer polyethylene films, and can also serve as compatibilizers for non-blended polymers, nanocomposites, and wood-fiber-reinforced polypropylene polymers.
High Melt Strength Polylactic Acid (HMS-PLA)
Polylactic acid (PLA) is a biodegradable and renewable polyester. Due to its linear chain structure, it has low melt strength and melt elasticity, which limits its application in fields where these properties are required.When polylactic acid reacts with Nouryon’s Trigonox 301 in an extruder, it forms long side chains and produces high melt strength polylactic acid (HMS-PLA). Trigonox 301 can be safely added to a polylactic acid solution in liquid form or used as a masterbatch for polylactic acid pellets.
Its long-branched chain structure and high melt strength result in high-melt-strength PLA with virtually unchanged MFI and a broader MWD. It also exhibits higher low-shear viscosity and shear-thinning properties at high shear viscosity, as well as greater melt elasticity.