1,4-Phenylene Diisocyanate (PPDI), identified by CAS number 104-49-4, is a key aromatic diisocyanate with a unique set of physical and chemical properties that dictate its handling, storage, and application. For professionals in the chemical industry, a thorough understanding of these characteristics is vital for safe and effective utilization, whether in polyurethane production or as a pharmaceutical intermediate.

Physically, PPDI typically presents as a white flake solid. Its melting point is generally in the range of 96-99 °C, which is higher than many other common diisocyanates. This solid form at room temperature can influence handling procedures, often requiring controlled heating for melting and processing. While solubility in water is limited (partly miscible), it is generally soluble in various organic solvents, a property exploited in solution-based reactions.

Chemically, the isocyanate (-N=C=O) groups are highly reactive. PPDI readily reacts with compounds containing active hydrogen atoms, such as hydroxyl (-OH), amino (-NH2), and carboxyl (-COOH) groups. The most well-known reaction is with polyols to form polyurethanes, creating urethane linkages. This high reactivity is also the basis for its use in other chemical syntheses, including as a pharmaceutical intermediate.

However, this reactivity also means that PPDI is sensitive to moisture and can react with water to form unstable carbamic acids, which decompose to amines and carbon dioxide. This reaction can lead to undesirable side products and pressure build-up in sealed containers. Therefore, proper storage and handling are paramount.

Handling and Storage Guidelines:

  • Moisture Exclusion: PPDI should be stored in tightly sealed containers under a dry inert atmosphere (e.g., nitrogen) to prevent contact with atmospheric moisture.
  • Temperature Control: Store in a dry, cool, and well-ventilated place, away from direct sunlight and heat sources. While it is a solid, elevated temperatures can accelerate degradation.
  • Personal Protective Equipment (PPE): When handling PPDI, it is essential to wear appropriate PPE, including chemical-resistant gloves, safety goggles or face shield, and protective clothing. Respiratory protection may be necessary in areas with potential airborne exposure.
  • Ventilation: Always handle PPDI in a well-ventilated area or under a fume hood to minimize inhalation exposure.
  • Incompatibility: Keep PPDI away from water, alcohols, amines, acids, bases, and oxidizing agents.

As a reputable manufacturer and supplier, we ensure our 1,4-Phenylene Diisocyanate is produced and packaged to maintain its integrity. If you are looking to buy PPDI and require detailed safety data sheets (SDS) or further guidance on handling and applications, please contact us. We are your trusted source for quality PPDI in China.