Selective pyrolysis of polystyrene to that with a desired low polymeric degree

Abstract

ABSTRACT:To obtain low polymeric polystyrene (PS), pyrolysis of high polymeric PS in solution was studied in the temperature range from 290 to 400°C by using additives or acid catalysts. The low polymeric PS targeted here was that with average molecular weight of 10 4 . When the feed PS was pyrolyzed in tetralin by adding sulfur or diphenyl disulfide, the molecular weight of PS decreased greatly, even at lower temperatures, and the desired low polymeric PS was formed in a relatively large amount at the temperatures below 350°C. The degradation behavior was able to be explained in terms of a random polymer chain scission mechanism initiated by sulfur radicals formed from the additives.

Thermal Degradation of Polystyrene by Lewis Acids in Solution

“…Because of inherent problems with high viscosity, commercialization of the process is lacking. Degradation of polymers in solution has been proposed to amend some of the problems encountered in pyrolysis. , The thermal degradations of polystyrene (PS), poly(styrene−allyl alcohol), poly(methyl methacrylate),and poly(vinyl acetate) in solution have been investigated.…”

Modeling the Evolution of the Full Polystyrene Molecular Weight Distribution during Polystyrene Pyrolysis

“…11 It was proposed that this low molecular weight polystyrene fraction could be used to make polystyrene products where low molecular weight polystyrene (average molecular weight ∼ 10 4 ) is desired. 11 Extensive research has been performed on degrading polystyrene and other styrene-based polymers to produce a low molecular weight polymer. [11][12][13][14] These works focused on degrading styrene-based polymers in various solvents to determine the effect of the solvents on degradation rates and the degradation mechanism.…”

“…11 Extensive research has been performed on degrading polystyrene and other styrene-based polymers to produce a low molecular weight polymer. [11][12][13][14] These works focused on degrading styrene-based polymers in various solvents to determine the effect of the solvents on degradation rates and the degradation mechanism.…”

“…Recently, an alternative to the complete pyrolysis of polystyrene has been suggested, which involves the partial degradation of high molecular weight polystyrene (average molecular weight > 10 5 ) to produce a low molecular weight polymer . It was proposed that this low molecular weight polystyrene fraction could be used to make polystyrene products where low molecular weight polystyrene (average molecular weight ∼ 10 4 ) is desired . Extensive research has been performed on degrading polystyrene and other styrene-based polymers to produce a low molecular weight polymer. − These works focused on degrading styrene-based polymers in various solvents to determine the effect of the solvents on degradation rates and the degradation mechanism.…”

“…Polystyrene properties are sensitive to the shape and breadth of the MWD, − and the ability to predict the evolution of the MWD is needed. Results were shown for how the evolving MWDs of styrene-based polymers were affected by the presence of various solvents and different degradation temperatures, − but no modeling work was performed.…”