Anionic solution copolymerization of α-methylstyrene with conjugated dienes above the ceiling temperature of α-methylstyrene

International Conference and Exhibition on Polymer Chemistry

November 14-16, 2016 Atlanta, USA

Adel F Halasa

Ohio University, USA

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

The successful copolymerization of �±-methylstyrene with conjugated dienes such as 1,3-butadiene, isoprene and/or styrene was achieved by anionic solution polymerization in hexane using formulated catalyst systems at the ceiling temperature of �±-methylstyrene. This polymerization is unique, since �±-methylstyrene cannot homopolymerize above its equilibrium ceiling temperature of 60�°C. Anionic copolymerization of 1,3-butadiene and �±-methylstyrene was first performed in hexane at 65�°C using 2/2/1 molar ratio of three different types of catalyst systems; cesium 2-ethylhexoxide (CsOR)/dibutylmagnesium (Mg(Bu)2)/ N,N,Nâ��,Nâ��-tetramethylethylene diamine (TMEDA), CsOR/TMEDA/n-butyl lithium (n-BuLi), and potassium amylate (KOAm)/ TMEDA/Mg(Bu)2. Polymers produced from the CsOR-based system showed faster incorporation rates of �±-methylstyrene than the KOAm-based system, resulting in the composition of �±-methylstyrene as high as 50% compared to a maximum of approximately 25% for the KOAm. Copolymerizations have also been successfully carried out using CsOR/TMEDA/n-butyl lithium (n-BuLi), although other n-BuLi containing systems were not successful. Other monomers such as isoprene and styrene can be used with the CsOR/ TMEDA/Mg(Bu)2 catalyst system to produce randomly �±-methylstyrene incorporated multiblock diene copolymers.

Biography :

Email: halasa@uakron.edu