A solid-state ~13C NMR study on phase heterogeneity in the miscible blend of amorphous poly(benzyl methacrylate) with semicrystalline poly(ethylene oxide)

摘要

Therotating-frame spin-I:lttice relaxation time for protons,T1P(IH), was measured indirectly from f3CcP/MAS/DD NMR to probe possible molecular scales of heterogeneity in the miscible poly(benzyl methacrylate) (PBzMA)/poly(ethylene oxide) (PEa) blend over the whole composition range. According to the NMR results, only one phase was observed for the blends in which the PEa component is less than 16% (w/w). This miscible amorphous phase withPBzMA andPEa chains was mixed at the molecular level. Three phases were detected for the blends with PEa component >16%,. containing one mjsGible homQgenous PBzMA-rich phase, one constrained PEa phase and one crystalline PEa phase. The PEa component asymptotically increases in the miscible homogenous PBzMA-richphase as the PEa composi- tion increases,. NMR analysis helped resolve the complex phase domains in the PBzMA/PEa blend that is composed of an amorphous roixture of PBzMA/PEa and crystalline PEa spherulite regions. The intra. and inter-lamellar domains in the PEa spherulites are influenced and complicated by the surrounding amorphous PBzMA/P￡a mixture with varying composition.