Styrene self polymerization kinetics
Styrene self polymerization kinetics
(OP)
I am looking for the rate of (self) polymerization of styrene as a function of time and temperature. The intention is to estimate the content of polymer (polystyrene)that can be formed in a liquid styrene monomer pipe.
Thanks.
Thanks.





RE: Styrene self polymerization kinetics
Uninhibited styrene can very rapidly result in autothermal (runaway) polymerization if it gets started. Plugging the line or increased viscosity from the presence of polymer will be the least of your worries. Relief design will require great care. I've seen a 24" diameter uninhibited styrene tank with a 4x10" relief valve on it for that reason...Check the guidelines for safe storage and handling of styrene published by various styrene suppliers.
RE: Styrene self polymerization kinetics
I refer to this because it is documented. However, i know a similar excercise was successful in pipeline continuous polymerisation process but have no details. Viscosity is a good indicator of molecular weight (ASTM D 2512? or something like that).
JMW
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RE: Styrene self polymerization kinetics
Styrene condenses with itself in a Diels-Alder reaction to form a dimer (Diels-Alder adduct)which acts as a free radical initiator. Polymerization proceeds by free radical initiation. The of formation of the diels-alder adduct and of polymer is temperature dependent.
The definitive work on styrene thermal polymerization can be found in an article by Albert Hui and Archie Himielec.
J. Applied Polymer Science, Vol. 16, 749-769, 1972. At 140 C styrene conversion is about 20% after 1 hour.
Inhibitors act to minimize polymerization under normal storage condition. As temperature increases free radical production increases and the inhibitor is overwhelmed.
Bill C
RE: Styrene self polymerization kinetics
A known polymerization inhibitor for styrene and butadiene is para-tert-butyl-cathechol usually called by its acronym PTBC. Dosages are around 10 ppm.