Polymerization of 2-Ethyl-2-oxazoline Using Di-, Tetra-, and Hexafunctional Ruthenium Tris(bipyridine) Metalloinitiators
Polymerization of 2-Ethyl-2-oxazoline Using Di-, Tetra-, and Hexafunctional Ruthenium Tris(bipyridine) Metalloinitiators
复制标题
使用二、四和六官能钌三(联吡啶)金属引发剂聚合 2-乙基-2-恶唑啉
DOI：
10.1021/ma990816o
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发表时间：
1999
期刊：
影响因子：
5.5
通讯作者：
C. Fraser
中科院分区：
文献类型：
--
作者：
John E. McAlvin;C. Fraser
具有两个、四个和六个氯甲基官能度的钌试剂[（bpy）nRu{bpy（CH 2Cl）2}3-n]（PF 6）2（n = 0−2）被用作用于2-乙基-2-恶唑啉的阳离子聚合的多官能金属引发剂，以生成具有窄分子量（MW）分布的橙子玻璃状聚合物。通过GPC相对于PMMA标准物测定MW，并通过GPC与多角度激光散射（MALLS）检测测定所选样品的MW。在线二极管阵列UV/维斯光谱分析结合GPC MW测定证实了洗脱聚合物中存在[Ru（bpy）3]2+发色团。聚合物是发光的，它们表现出类似于不含金属的PEOX对应物的热性能（Tg ≤ 54 °C;在365 - 385 °C开始热分解）。与使用不稳定的六官能Fe引发剂进行的反应不同，可以实现MW> 100 K和聚合度（dp）>200的反应，Ru中心聚合物达到10025 K的MW上限，而不管其上的官能度的数量如何。
Ruthenium reagents with two, four, and six chloromethyl functionalities, [(bpy)nRu{bpy(CH2Cl)2}3-n](PF6)2 (n = 0−2), were employed as multifunctional metalloinitiators for the cationic polymerization of 2-ethyl-2-oxazoline to generate orange, glassy polymers with narrow molecular weight (MW) distributions. MWs were determined by GPC vs PMMA standards and for selected samples by GPC with multiangle laser light scattering (MALLS) detection. In-line diode array UV/vis spectroscopic analysis coupled with GPC MW determination confirms the presence of [Ru(bpy)3]2+ chromophores in the eluting polymers. Polymers are luminescent, and they exhibit thermal properties analogous to the metal-free PEOX counterparts (Tg ∼ 54 °C; onset of thermal decomposition at 365−385 °C). Unlike reactions run with a labile hexafunctional Fe initiator, reactions wherein MWs > 100K and degrees of polymerization (dp) >200 are attainable, Ru-centered polymers reach an upper MW limit of ∼25K regardless of the number of functionalities on ...