Procedures for homogeneous anionic polymerization

Abstract

This report is a rev ie w of the procedures and equipm e nt used in the preparation of polyniers of predi ctabl e molec ular weights and narrow mol ec ular weight di stributions. The monomers con sidered in detai l are styre ne, a-methyl styre ne, iso pre ne , and butadiene.Key Words: Ho moge neo us anioni c polymerization, monodi s pe rse, polystyrene, poly-a-me thylstyre ne, polyiso pre ne, an d polybutadiene.

Pyrolysis of anionic and thermally prepared polystyrenes

“…The permeation limit of the membranes was checked in the following fashion. A series of low-molecular weight polystyrenes were synthesized by anionic polymerization [18] and were characterized on the vapor pressure osmometer. They were then recharacterized on the high speed membrane osmometer.…”

Effects of phase separation on network and viscoelastic properties in SBS thermoplastic elastomers

“…Styrene-butadiene-styrene blockpolymers with low styrene content (15-25 wt.-%) were synthesized by common sequential anionic techniques [8]. s-B~ityllithium was used as initiator in cyclohexane as solvent.…”

Blockpolymers of styrene and isoprene with variable interphase: Morphology and dynamic viscoelastic behaviour

“…For two-phase systems the volume fraction of the copolymer phase Vzs is zero and only one integral from zero to unity, corresponding to one interphase transition only with the volume distribution function of equation (7), appears in equation (8). The modulus G,* normal to the lamellar planes is obtained by summing up the shear compliances J* in an analogous way as in equation (8) and converting back to moduli by:…”

“…The anionic polymerization was carried out at 25 ~ by means of the usual high vacuum techniques and equipment [8]. The used solvent was a mixture of benzene/20 volume% triethyiamine, the initiator was s-butyl-lithium.…”

“…In the purification of solvents and monomers known prescriptions [8] were followed except some modifications described elsewhere [9]. The anionic polymerization was carried out at 25 ~ by means of the usual high vacuum techniques and equipment [8].…”