VISUALIZATION OF NETWORK STRUCTURE IN POLY(BUTADIENE) POLYSTYRENE PSEUDO-INTERPENETRATING POLYMER NETWORKS BY TRANSMISSION ELECTRON-MICROSCOPY

Pseudo interpenetrating polymer networks (PIPNs) of 1,4-cis-poly(butad iene) and polystyrene (PS) have been prepared to directly examine the polymer network structure in IPNs by transmission electron microscopy (TEM). Samples of crosslinked cis-poly(butadiene) (PB) were swollen wi th styrene monomer, which en was polymerized in situ to form sequentia l PIPNs. TEM observations were performed using samples stained with 2% osmium tetroxide following the procedure of Shiibashi et al. Network structures of crosslinked cis-pb were visualized in the PIPNs. The mea n size of the unit roughly square plaquette of the network seen in the electron micrographs was in relatively good agreement with the unpert urbed root mean square end-to-end distance of PB sub-chains between cr osslinks.