Ultrasonics / High Shear in Polymerization

Use of ultrasonics and high shear for polymer breakdown (degradation) is widely published. However, publications of their use during polymerization are not of consistent quality. The presenter’s work on mass (bulk), solution, and micro-suspension and emulsion polymerization, using ultrasonics / high shear will be reported and compared with the published work. Scientific explanations will be given for the differences. The presenter has successfully developed processes which have saved millions of dollars. Examples will be given of lessons learned, including the following DOs and DON’Ts:

DOs:

• 1.Make good, accurate, scientific observations and repeat your work.
• 2.Find explanation for observed differences from your hypothesis, and change your hypothesis if needed, in view of the above scientific observations.
• 3.Make final 10-25% payment contingent on equipment performance validation.
• 4.Note surprising observations, find explanation and think of exploiting these.
• 5.Provide for contingencies, e.g., 10-50% extra horsepower for pumps, agitators, mixers, for future higher throughputs or higher viscosities, and consider the use of variable frequency drives (VFDs).
• 6.Work with willing equipment vendors to resolve in constructive ways, with creative solutions if the equipment underperforms.
• 7.Use established scale up parameters, such as constant tip speed (other choices are shear number or horsepower per unit volume).
• 8.Be open minded and receptive to input from others.

DON’Ts:

• 1.Trust all claims of equipment vendors without doing performance tests.
• 2.Trust all published work without duplicating or analyzing it carefully (DO challenge it where it seems wrong).
• 3.Believe in hearsay or opinions without corroborating from reliable sources.
• 4.Despair if you get negative/unexpected results (DO look for explanations).
• 5.Generalize, or get emotionally attached to a particular type of equipment for all applications, just because it worked wonderfully for one application. It may not work for the new application, or there may be a lower cost/ better alternative.