How critical is KSO4 in styrene polymerization?

[dobit]

In batch process of styrene polymerization,I know that in terms of mass ratio of other ingredients to styrene, Potassium per sulphate (KSO4) has the smallest ratio. Does anyone has data on how KSO4 do affect beads size distribution during polymerizartion?

 

[bchoate]

Bill Choate
Potassium persulfate (PPS or KPS) is the free radical polymerization initiator. Since the process contains PPS and styrene, I guess that it is a latex producing emulsion polymerization. Particle size is a function of several factors. The process may be using an emulsifying agent; a nonionic emulsifying agent will speed up the decomposition of PPS (and the reaction). PPS is a water soluble free radical initiator. The molecular weight of the polymer produced will depend upon the amount of PPS used, whether a chain transfer agent (dodecyl mercaptan or other), and the time/temperature conditions of the reaction. This is just a short answer to the question.
Bill Choate

 

[dobit]

Thank you bchoate for your brief response. Our beads size distribution from our batch process range from 200 to 800 microns. These polystyrene beads will later be injected with pentane in another batch process and the final product will be use in making of foam cups and foam blocks for house insulation.

Based on your answer, It is possible to adjust molecular weight of the beads by varying amount of PKS while keeping temperature/time condition the same. I thought adjustment of the molecular weight depends on amount of initiator (Perkadox in our own case), time and temperature.

Thanks,

Dobit