Microstructure Characterization of Short-chain Branching Polyethylene with Differential Scanning Calorimetry and Successive Self-nucleation/Annealing Thermal Fractionation

作     者：Yan-hu Xue Yan-hui Wang Yan-di Fan He-ran YangState Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Tao Tang Shu-qin Bo 姬相玲 

作者机构：State Key Laboratory of Polymer Physics and ChemistryChangchun Institute of Applied Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2014年第32卷第6期

页      面：751-757页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070305[理学-高分子化学与物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China(Nos.20734006 and 50921062) 

主　　题：Polyethylene Methylene sequence length (MSL) Microstructure Successive self-nucleation and annealing(SSA) SCB. 

摘      要：A series of the copolymers of ethylene with 1-hexene （M1-M9） synthesized by metallocene catalyst Et[Ind]2ZrC1JMAO was studied by differential scanning calorimetry and successive self-nucleation and annealing （SSA） thermal fractionation. The distribution of methylene sequence length （MSL） in the different copolymers was determined using the SSA method. The comonomer contents of samples M4 and M5 are 2.04 mol% and 2.78 mol%, respectively. Both M4 and M5 have low comonomer content and their MSL distribution profiles exhibit a monotonous increase trend with their MSL. The longest MSL of M5 is 167, and its corresponding molar percent is 43.95%, which is higher than that of M4. Moreover, the melting temperature （Tm） of M5 is also higher than that of M4. The comonomer contents of samples M7, M8, and M9 are 8.73 mol%, 14.18 mol% and 15.05 mol%, respectively. M7, M8, and M9 have high comonomer contents, and their MSL distribution profiles display unimodality. M7 has a lower peak value of 33 and a narrow MSL distribution, resulting in a Tm lower than that of M8 and M9. The MSL and its distribution are also key points that influence the melting behavior of copolymers. Sometimes, MSL and its distribution of copolymers have a greater impact on it than the total comonomer contents, which is different from traditional views.