Poly[styrene-b-maleated (ethylene/butylene)-b-styrene] (mSEBS) block copolymers and mSEBS/inorganic nanocomposites:I.Morphology and FTIR characterization

摘要

Self-assembled,[block copolymer]/[pure silicate and ORMOSIL] nanocomposites were created via sol-gel processes for silicate and organically-modified silicate (ORMOSIL) monomers in the presence of sulfonated maleated poly(styrene-b-ethylene/butylene-b-styrene) (mSEBS).Microscopic and small angle X-ray scattering (SAXS) studies showed that unmodified mSEBS has hexagonal packed PS cylinder morphology,but sulfonation causes the morphologies to be frustrated.The morphology of pure silicate nanoparticle-containing nanocomposites is phase separated,although further frustrated.The morphologies of the ORMOSIL-modified materials were different,less-ordered and show the influence of the nature of the organic group on self-assembly.Despite differences in morphology,degree of order,and different inter-domain spacings,all but the pure silicate-containing hybrid have the same PS domain width (25-30 nm).The dispersed nanoparticles are roughly spherical and some can grow to exceed the block copolymer domain sizes.All filled samples have inter-domain spacings,derived by SAXS analysis,that are larger than that of the corresponding unfilled sulfonated mSEBS,which reflects insertion of silicate or ORMOSIL structures.FTIR spectroscopy indicated successful Si-O-Si bond formation,which shows that the inserted particles are indeed crosslinked.