Piloting of anionic polymerization of styrene in tetrahydrofurant
โ Scribed by Marko Saban; George Liebermann; Alex Jay; An-Chang Shi; Nam Ro; William Dale; Pat Forgione
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 942 KB
- Volume
- 78
- Category
- Article
- ISSN
- 0008-4034
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Anionic polymerization of styrene in THF with nโbutyllithium/alphaโmethylstyrene initiator is described as a first step in preparation of a styrenic block copolyโmer. In order to suppress rapid decay of living alphaโmethylstyrene unimers, which occurred at room temperature, the initiation reaction was carried out at โ20(+5)ยฐC. The kinetic parameters of this decay reaction were determined and used for process optimization. By combining experiments with modelling of styrene propagation reaction all key process parameters were defined for lโL, 38โL, and 189โL reactors. A good match was demonstrated between the model and experimental propagation exotherm for semibatch reaction conditions. Overall, it was demonstrated that technical grade THF and styrene could be used at pilot plant scale to prepare wellโdefined polymers up to Mn 22 000 via the โlivingโ polymerization mechanism. The resulting polymers had narrow molecular weight distributions (1.06 < Mw/Mn < 1.30).
๐ SIMILAR VOLUMES
Anionic polymerization of styrene in CSTR processes demands monomers which are highly pure. Lithium aluminum hydride (LAH) is a highly reactive material which reacts with the impurities in styrene that interfere with anionic polymerization. The LAH/impurity reaction products are not compatible with