Polymers, Coatings, Adhesives

What is the process of Polymer Devolatilization?

For optimal purification of polymers, wiped-film molecular distillation plays an important role as a final or near-final process step.  In the manufacturing of polymers, reactions are run where monomer building blocks in a solvent base are joined together to create polymer chains of desired lengths.  In many of these reactions, an excess of monomer is maintained to keep the polymerization process going in a controlled, predictable manner. After these reactions, the polymer product will contain shorter chains, monomers, solvent and other lower boiling point contaminants which must all be removed.  In some applications such as biopolymer implants and injections into patients, it is absolutely critical that not only solvents be removed but monomers and short chains as well.  Silicone breast and other types of implants where these were not removed led to the major medical problems of years past.

Because these more volatile components have significantly lower boiling points than the main product, distillation is the preferred means of removal.  But simply boiling of the polymer products in batch vessels, even under vacuum, for evaporating off of the lighter components can cause more problems than it solves.  The heat exposure time which can go on for hours or longer, often causes degradation including breaking of the chains into shorter chains and monomers as well as causing cyclization of chains, forming a well known biologically hazardous contaminant.  Where the polymer is high in viscosity, batch devolatilization will take considerably longer due to mass transfer limitations, making the problem worse. 

Wiped-film distillation processing of these products is a significant improvement in polymer devolatilization.  The equipment is designed to reduce heating exposure time from hours to seconds under high vacuum in a continuous flow through a heated wall with rotating wipers, creating a very efficient evaporation.  The pressure drop under high vacuum conditions in the system is greatly reduced via the condenser surface being a very short distance (short-path) from the evaporation surface, aiding in the overall efficiency or the process resulting directly to increased purity and yield of final product.  There is normally a prior pass through another wiped-film still to remove dissolved gasses and light solvents, enabling the second pass, removal of monomers and short chains, to perform optimally, at greater vacuum levels without undesired flashing.

Key Features of Our Polymer Devolatilization Equipment:

1. Silicone Purification: Experience unmatched purity with our advanced silicone purification technology.
2. Precision Engineering: Our equipment is meticulously designed for optimal performance, ensuring precise devolatilization.
3. Efficient Residue Removal: Our polymer devolatilization equipment removes residue concerns as our equipment excels in thorough and efficient removal.
4. Adaptable to Diverse Industries: From plastics to rubber, our solutions cater to a spectrum of industries, providing versatile applications.

Process Applications:

• Devolatilization and Degassing of Prepolymers, Biopolymers 
• Purification of Epoxy Resins, Latexes, Isocyanates, Urethanes, Silicones, Acrylics and others 
• Removal of cyclic siloxanes from silicones including Polysiloxane Oils
• Purification & Concentration of Monomers
• Purification & Concentration of Polymers, Plasticizers, UV Inhibitors (keep UV with this bullet)
• Stripping Monomers from Polymers
• Separation between Monomers, Dimers, Trimers, etc. 
• Purification of Adhesives