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Solid-state 13 C NMR analyses have been performed to obtain information about the crystalline-noncrystalline structure for metallocene-catalyzed linear low-density polyethylene (MLLDPE) isothermally crystallized from the melt. 13 C spin-lattice relaxation time (T1C) and 13 C spin-spin relaxation time (T2C) analyses have revealed that three components with different T1C and T2C values exist for MLLDPE, which are assignable to the crystalline, crystalline-amorphous interfacial, and rubbery amorphous components. Using such differences in T2C, we have separately recorded the spectra of interfacial and amorphous components and then resolved the fully relaxed DD/MAS spectrum of MLLDPE into the three components. As a result, it has been found that the thickness of the interfacial region is about 3 nm, in good accord with the previous result for bulk-crystallized high-density polyethylene (HDPE). T1FH and T2C analyses have also revealed that butyl branches are excluded out from the crystalline region and are almost equally distributed in the crystalline-amorphous interfacial and amorphous regions. It has been also found that the molecular mobility is somewhat more enhanced in the interfacial region for MLLDPE compared with the case for HDPE. The same analysis is applied to Ziegler-Natta-catalyzed LLDPE isothermally crystallized from the melt as well as those quenched samples, and the crystallinenoncrystalline structures of the samples are discussed.

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