1. General Information
Product Name: Donor B
Chemical Name: Diisobutyl dimethoxysilane, (DIBDMS)
Molecular Formula: C10H24O2Si
Molar Mass: 204.4 g/mol
2. Chemical Properties
Purity %: 99 Min
Moisture ppm: 100 Max
A high – performance additive widely used in the polymerization industry as an external electron donor in Ziegler – Natta catalyst systems for polypropylene production, playing a crucial role in enhancing and regulating the performance of the catalyst.
3. Physical Properties
Appearance: clear, colorless liquid.
Boiling Point: Boils at 72°C under 760 mmHg. The relatively low boiling point makes it suitable for use in polymerization processes that operate at moderate temperatures, without the need for excessive heating that could potentially damage the catalyst or the polymer being produced.
Solubility: Insoluble in water, but highly soluble in most organic solvents such as toluene, hexane, and ethanol. This solubility profile enables it to be easily incorporated into the organic – based catalyst systems and polymer matrices, facilitating its function as an electron donor.
4. Chemical Reactivity and Stability
Stability: Donor B is highly stable under normal storage conditions. When stored in a cool, dry place away from direct sunlight, heat sources, and strong oxidizing agents, it maintains its chemical integrity over an extended period.
Reaction Mechanism: In the Ziegler – Natta catalyst system for polypropylene production, Donor B acts as an external electron donor. It coordinates with the transition metal in the catalyst, modifying the catalyst’s structure and reactivity. This coordination enhances the catalyst’s stereospecificity, allowing for the production of polypropylene with a high degree of isotacticity. Additionally, it improves the catalyst’s hydrogen – modulation sensitivity, enabling better control over the molecular weight and distribution of the polypropylene chains. This results in polypropylene products with improved mechanical properties, such as higher tensile strength, stiffness, and heat resistance, making them suitable for a wide range of applications.
5. Applications
Polypropylene Production
All – Polypropylene (homo – PP): In the production of homo – PP, Donor B is used to increase the isotacticity of the polymer. High – isotacticity homo – PP has excellent mechanical properties, making it suitable for applications such as injection – molded parts for automotive components, household appliances, and industrial equipment.
Random Copolymer Polypropylene (rPP): When producing rPP, Donor B helps in controlling the copolymerization process. It allows for the precise incorporation of comonomers, such as ethylene, into the polypropylene chain. This results in rPP with improved transparency, flexibility, and impact resistance, making it ideal for applications like food packaging films, medical packaging, and consumer goods.
Impact Copolymer Polypropylene (iPP): In iPP production, Donor B plays a crucial role in optimizing the rubber – phase dispersion and the overall morphology of the polymer. This leads to iPP with enhanced impact strength, especially at low temperatures. iPP is commonly used in applications where high – impact resistance is required.
6. Usage and Dosage
Usage: Donor B is typically added to the polymerization reaction system along with the Ziegler – Natta catalyst components. It can be introduced in a pre – diluted form or directly into the reactor, depending on the specific production process and equipment.
Dosage: The recommended dosage of Donor B in polymerization typically depends on several factors, including the specific polymerization process, the type and amount of catalyst used, and the desired properties of the final polymer product. Generally, in the polymerization of polypropylene using Ziegler – Natta catalysts, the dosage of Donor B is usually in the range of 0.1 – 5.0 mmol per gram of catalyst.
7. Advantages
High – Efficiency Catalyst Modification: Even at low dosages, Donor B can significantly enhance the performance of Ziegler – Natta catalysts. It improves the catalyst’s stereospecificity and hydrogen – modulation sensitivity, leading to higher – quality polypropylene products with improved mechanical properties.
Versatility in Polymerization Processes: Donor B is compatible with a wide range of Ziegler – Natta catalyst systems and can be used in different polypropylene production processes, including slurry, gas – phase, and bulk polymerization.
Consistent Product Quality: By precisely controlling the polymerization process and the properties of the polypropylene product, Donor B helps in ensuring consistent product quality. Products made with Donor B – enhanced polypropylene have reliable performance and characteristics, reducing the risk of product failures and recalls.
8. Handling and Safety
Personal Protective Equipment: When handling Donor B, it is recommended to wear appropriate personal protective equipment, including chemical – resistant gloves, safety goggles, and protective clothing.
Ventilation: Ensure good ventilation in the handling area
9. Packaging and Storage
Packaging: Usually packed in 200 – liter iron drums with an inner protective layer. Each drum contains 180 kg of Donor B. Additionally, the drums are filled with nitrogen to create an inert atmosphere, which helps maintain the chemical stability of Donor B during storage and transportation.
Storage: Store in a cool, dry place, away from direct sunlight and heat sources. Under proper storage conditions, it has a shelf – life of one year. Regularly inspect the stored product to ensure its quality and effectiveness before use in production processes.