catalysts to promote polymer chain growth in polyolefin manufacturing processes

Polyolefins & Catalysts Manufacturing

Polyolefins are a family of polyethylene (PE) and polypropylene (PP) thermoplastics belonging to the top five groups of plastic materials produced globally. With about 165 million metric tons annually, PE and PP account for two-thirds of the thermoplastics with the highest consumption worldwide. Polyolefins are used in various applications such as automotive parts, rigid and flexible packaging, films, appliances, pipes or medical components & devices.

Polyolefins like polyethylene (PE) and polypropylene (PP) are popular because of their capability to replace costly and resource-intensive materials. They also provide additional property benefits of being lightweight, chemically and mechanically resistant, and easy to shape into products.

Polyethylene (PE) comprises copolymers of ethylene with different amounts of an α-olefin comonomer to decrease the density and crystallinity of the polymer, which widens the range of applications. The most commonly used α-olefins are 1-butene, 1-hexene, and 1-octene. Polypropylene (PP) resins are mostly isotactic materials. Furthermore, there are different variations of propylene copolymers available next to homo-PP materials, such as random propylene/ethylene copolymers and impact propylene/ethylene copolymers.

Different process technologies have been developed to manufacture PE and PP polymers, including bulk, gas phase or slurry processes. The catalyst is the heart of all polyolefin manufacturing processes, and its role is to promote polymer chain growth. For PE and PP, Ziegler and Ziegler-Natta type catalysts are very commonly used. For PE, Ziegler-Natta catalysts account for almost 45 % of all polymerization processes, whereas for PP, the number is even higher at 95 %.

Our Catylen® product range consists of key components used for the formulation of PE and PP polymerization catalysts. They decisively contribute to the selectivity and productivity of a catalyst system. The brand name Catylen® comprises support materials (Catylen® S) and donors (Catylen® D) to formulate state-of-the-art Ziegler-Natta catalysts.

  • Catylen® S is a series of magnesium ethanolate based support materials of different sizes and morphology.
  • Catylen® D series is an extensive range of external and internal donors.

Together, both Catylen® product families offer you a toolbox to select the right components for your individualized polyolefin catalyst. Furthermore, we offer our expertise in developing and producing customized catalyst systems.

Our technical experts are happy to support you in the selection process of catalyst components, customized solutions, and even in the custom manufacturing of the complete catalyst system.

External Donors are an essential process additive for producing polypropylene involving Ziegler-Natta (ZN) catalysts. They are part of the catalyst system that controls the performance and product capabilities regarding stereoselectivity, molecular weight, activity, comonomer incorporation, rubber composition and more. If the internal donor is based on a phthalate structure, they are applied in nearly 1:1 ratio by weight with the actual ZN catalyst. However, for a non-phthalate internal donor, the required amounts of an external donor may be significantly lower.

Our Catylen® D product family is utilized by the major polypropylene (PP) producers worldwide and resembles the most popular silane-based external donors, such as C-, D-, B-,P-, N- and other donors, covering all PP production technologies in use today.

We provide state-of-the-art high-purity and license-free external donors as neat components, customized donor blends or dilutions in mineral oil or organic solvents.

Your benefits at a glance:

  • Rely on our product’s consistency and high quality for a maximized PP plant utilization.
  • We utilize our worldwide infrastructure to ensure sustainable accessibility, on-time and reliable delivery. 

Do you are fac unprecedented challenges in your process? Are you unable to find what you are looking for in our comprehensive portfolio? Speak with one of our professional experts who are happy to assist.

Internal donors are essential components of a Ziegler-Natta (ZN) catalyst system providing the stereoselectivity, hydrogen response, molecular weight and comonomer incorporation capability and influencing the catalyst activity in the polymerization of propylene. The donor compounds being applied within the actual ZN catalyst synthesis are called “internal donors” and are usually organic molecules, such as phthalates, benzoates, esters or ethers. 

Internal donors, especially of the phthalate type, partially detach from the ZN catalysts and must be supplemented by external donors during the polymerization process. Our internal donor, Catylen® D 2100, is an aliphatic diether, with one of its main characteristics being process stability. With Catylen® D 2100 being part of the catalyst formulation, only small amounts, if any, of external donor is required to obtain the desired polypropylene (PP) polymer grades. Phthalate-based internal donors and aromatic components, in general, are regarded as critical for applications in food packaging and toys. This brings an additional advantage of using our aliphatic diether Catylen® D 2100 into play:  It offers unrestricted product applicability.

Furthermore, Catylen® D 2100 significantly increases the activity and hydrogen response of the ZN catalyst while improving the material properties by a decreased crystalline PE split in the rubber phase of impact copolymer grades.

Upon request, Evonik also offers the exclusive custom manufacturing of other internal donors, starting from lab-scale up to commercial production.

Your benefits at a glance:

  • Using our highly effective internal donor Catylen D 2100, you won’t find any restrictions in regards to product application or regulatory and market requirements.
  • Rely on our worldwide commercial scale supply guaranteed by our strong infrastructure.

If you are looking for more information on internal donors, feel free to contact our experts, who are happy to provide any help you need.

The support material is the backbone of the heterogeneous polyolefin catalyst. It determines the catalyst performance and operability, as well as the polymer morphology and its downstream processability.

We offer a variety of solid supports such as the magnesium ethanolate based Catylen® S 100 and Catylen® S 300 series and the liquid support precursor Catylen® S 200.

We have over 50 years of experience in the production of magnesium ethanolate supports in various specifications represented by the Catylen® S 100 series, which are widely utilized in major slurry polyethylene (PE) and gas-phase polypropylene (PP) polymerization technologies.

The Catylen® S 300 series provides tailor-made and ready-to-use spherical support particle sizes between 10 µm and 35 µm with very narrow particle size distributions below 1, suitable for all PE and PP polymerization technologies. Catylen® S 300 based PP catalysts have a unique pore architecture and provide, in combination with internal donors such as Catylen® D 2100, excellent impact copolymerization capabilities and a superb morphology in combination with outstanding catalyst activities. The liquid Catylen® S 200 catalyst precursor is suitable to produce precipitated slurry PE Ziegler catalysts for High Density PE (HDPE) and Ultra High Molecular Weight PE (UHMWPE) grades. It can be provided as off-the-shelf grade or in a suspension with customized concentration.

All our Catylen® S support materials can be provided off the shelf or as individually customized grades. We assist you efficiently in optimizing your catalyst solutions and in developing your personalized end product - either by ready-to-use solutions or with tailor-made products, from lab-scale to commercial production.

Your benefits at a glance:

  • Take advantage of our magnesium ethanolate supports suitable for the manufacture of Ziegler and Ziegler Natta catalysts with a unique pore architecture resulting in excellent polymer powder morphologies
  • Use our Catylen® S series to design your very own tailor-made catalyst system or approach us to assist you in an exclusive collaboration project.

Whatever challenges you face throughout your polymerization process, our experts from custom catalysts are happy to assist.


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