Well-Defined Poly(4-vinylbenzocyclobutene):  Synthesis by Living Anionic Polymerization and Characterization

Abstract

Living anionic polymerization of 4-vinylbenzocylobutene was performed in benzene at room temperature using sec-butyllithium as the initiator. Results of the kinetic studies indicated the termination-and transfer-free nature of the polymerization. Homopolymers with predictable molecular weights and narrow molecular weight distributions were produced, excluding the interference of the cyclobutene rings during initiation and propagation. Thermogravimetric analysis of poly(4-vinylbenzocyclobutene) in air showed a small weight gain at ∼200°C, a rapid decomposition at ∼455°C, and a gradual decomposition at ∼566°C. This behavior was attributed to the formation of radicals from the pendent benzocyclobutene functionality through o-quinodimethane intermediates and simultaneous decomposition/cross-linking reactions at high temperature. The living nature of the polymerization was also examined via sequential copolymerization with butadiene to form diblock copolymers.

New polymers derived from 4‐vinylsilylbenzocyclobutene monomer with good thermal stability, excellent film‐forming property, and low‐dielectric constant

“…1). 7 Recently, polymers bearing BCB pendant groups have aroused much interest 8–11. Polymers from unique 4‐vinyl substituted BCB (4‐VBCB, Fig.…”

“…Polymers from unique 4‐vinyl substituted BCB (4‐VBCB, Fig. 1) have been developed by Baskaran and coworkers,9 which have exhibited good processing property, thermal stability, and low‐dielectric constant 9, 10. Russell and coworkers11(a,c,e,g) further developed a series of microstructure and nanostructure materials by using 4‐vinyl BCB specie as an attractive building block and discovered that the intramolecular crosslinking via ring‐openning reaction of BCB could lead to the formation of nanoparticles.…”

Anionic Polymerization: Recent Advances

“…Although the introduced functional groups were susceptible to reacting with both anionic initiators and growing chain-end anions, all of these styrene derivatives successfully underwent anionic polymerization in a living manner. The living anionic polymerization of functional styrenes has also recently been achieved, under carefully controlled conditions ( Figure 5.4) [13,19,20,[44][45][46][47][48][49][50][51]. More importantly, the nucleophilicities of the growing chain-end carbanions were drastically lowered by reducing the electron densities on the carbanions through the electron-withdrawing substituents, thereby causing such functional groups and chain-end anions to coexist.…”

Cationic Copolymerization of Isobutylene with 4-Vinylbenzenecyclobutylene: Characteristics and Mechanisms

“…Harth prepared single-molecule nanoparticles by regulating the collapse of linear polymer chains [26]. BCB-functionalized polymers and copolymers are synthesized through free-radical [27,28] and anion polymerization [25,29]. Few works have investigated the cationic polymerization of 4-VBCB, except for the research of Sheriff et al on the application of poly(styrene-coblock-4-VBCB)-polyisobutylene-poly(styrene-coblock-4-VBCB) in prosthetic heart valves [30].…”