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(butadiene) 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 with styrene monomer, which en was polymerized in situ to form sequential 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 mean size of the unit roughly square plaquette of the network seen in the electron micrographs was in relatively good agreement with the unperturbed root mean square end-to-end distance of PB sub-chains between crosslinks.