摘要
Two polyethylene（PE） resins（samples A and B） are synthesized as high-speed extrusion coatings with similar minimum coating thickness and neck-in performance but different maximum coating speeds. Both samples are separated into seven fractions using preparative temperature rising elution fractionation. The microstructures of the original samples and their fractions are studied by high-temperature gel permeation chromatography, Fourier transform infrared spectroscopy, 13 C nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and successive self-nucleation/annealing thermal fractionation. Compared with sample B, sample A has a broader MWD, more LCB contents, and less SCB contents. Moreover, sample A contains slightly more 30 ℃ and 50 ℃ fractions with lower molecular weights, and more fractions at 75 ℃ and 85 ℃ with higher molecular weight. The chain structure and its distribution in the two PE resins are studied in detail, and the relationship between the chain structure and resin properties is also discussed.
Two polyethylene（PE） resins（samples A and B） are synthesized as high-speed extrusion coatings with similar minimum coating thickness and neck-in performance but different maximum coating speeds. Both samples are separated into seven fractions using preparative temperature rising elution fractionation. The microstructures of the original samples and their fractions are studied by high-temperature gel permeation chromatography, Fourier transform infrared spectroscopy, 13 C nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and successive self-nucleation/annealing thermal fractionation. Compared with sample B, sample A has a broader MWD, more LCB contents, and less SCB contents. Moreover, sample A contains slightly more 30 ℃ and 50 ℃ fractions with lower molecular weights, and more fractions at 75 ℃ and 85 ℃ with higher molecular weight. The chain structure and its distribution in the two PE resins are studied in detail, and the relationship between the chain structure and resin properties is also discussed.
基金
financially supported by the National Basic Research Program of China(No.2005CB623806)
the National Natural Science Foundation of China(Nos.20734006 and 50921062)
