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Polystyrene–polyisobutylene network composites from in situ polymerizations
Author(s) -
Fu F.S.,
Mark J. E.
Publication year - 1989
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1989.070370924
Subject(s) - polystyrene , degree of unsaturation , materials science , styrene , composite material , elastomer , benzoyl peroxide , monomer , polymerization , polymer chemistry , polydimethylsiloxane , polyurethane , natural rubber , copolymer , polymer
Crosslinked networks of butyl rubber [polyisobutylene (PIB) with 2 mol % unsaturation] were swelled with various amounts of styrene containing 0.25–4.6 wt % benzoyl peroxide as initiator. Polymerization of the styrene in situ , by increase in temperature, gave novel elastomeric composites. Scanning electron micrographs suggest phase separation which is locked in at the microscopic level, with no evidence for the particulate domains seen in the similarly prepared polystyrene‐polydimethylsiloxane system. The wt % polystyrene (PS) extractible increased with increase in initiator concentration, which is consistent with decrease in the lengths of the PS chains being formed and grafted onto the PIB. Mechanical properties obtained in continuous extension showed maxima in their dependence on composition. Specifically, the ultimate strength ( f / A * ) m , maximum extensibility ε r , energy E r required for rupture, and permanent set Δ L / L 0 generally showed maxima in the vicinity of 50 wt % PS. The shortest‐chain PS samples generally showed the largest values of ( f / A * ) m , ε r , and E r , and the smallest values of Δ L / L 0 .