Tapered Multiblock Copolymers Based on Isoprene and 4-Methylstyrene: Influence of the Tapered Interface on the Self-Assembly and Thermomechanical Properties
Tapered Multiblock Copolymers Based on Isoprene and 4-Methylstyrene: Influence of the Tapered Interface on the Self-Assembly and Thermomechanical Properties
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DOI：
10.1021/acs.macromol.8b02669
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发表时间：
2019-02
期刊：
影响因子：
5.5
通讯作者：
E. Galanos;E. Grune;C. Wahlen;A. Müller;Michael Appold;M. Gallei;H. Frey;G. Floudas
中科院分区：
文献类型：
--
作者：
E. Galanos;E. Grune;C. Wahlen;A. Müller;Michael Appold;M. Gallei;H. Frey;G. Floudas
通过异戊二烯（I）和4-甲基苯乙烯（4 MS）的混合物在环己烷中的统计活性阴离子共聚来合成递变多嵌段共聚物是基于I和4 MS的极大不同的竞聚率（rI = 25.4和r4 MS = 0.007）。制备了不同分子量的递变多嵌段共聚物库（近似分子量为80、240和400 kg/mol）和嵌段数（P（I-co-4 MS）n，其中1 ≤ n ≤ 5），通过差示扫描量热法、流变学和拉伸测试研究了它们的热机械性能，后者通过小角X射线散射研究。通过对一系列由单体顺序加成得到的PI-b-P4 MS嵌段共聚物的有序-无序转变温度的测定，得到了I和4 MS链段之间的相互作用参数。所得到的χ（T）依赖性（χMFT = 23.2/T - 0.024和χFH = 36.0/T - 0.041）比相应的PI-b-PS系统中的弱。
The synthesis of tapered multiblock copolymers by statistical living anionic copolymerization of a mixture of isoprene (I) and 4-methylstyrene (4MS) in cyclohexane is based on vastly different reactivity ratios of I and 4MS (rI = 25.4 and r4MS = 0.007). A library of tapered multiblock copolymers was prepared with different molecular weights (approximate molecular weights of 80, 240, and 400 kg/mol) and number of blocks (P(I-co-4MS)n with 1 ≤ n ≤ 5), and their thermomechanical properties were investigated by differential scanning calorimetry, rheology, and tensile testing in relation to their nanodomain structure, the latter investigated by small-angle X-ray scattering. The interaction parameter between I and 4MS segments was obtained based on the order-to-disorder transition temperatures of a series of PI-b-P4MS diblock copolymers prepared by sequential addition of monomers. The obtained χ(T) dependencies (χMFT = 23.2/T – 0.024 and χFH = 36.0/T – 0.041) are weaker than in the corresponding PI-b-PS system,...