Abstract A series of poly(tert-butyl acrylate) (PtBA) based star-block copolymers were synthesized to obtain physically cross-linked shape memory polymers (SMPs) with body temperature triggering. First, PtBA star polymers were prepared via atom transfer radical polymerization (ATRP) to form the hard segment. Then star polymers were used as macro-initiators (MI) and combined with linear/non-linear derivatives of poly(ethylene glycol) (PEG), which build the soft segment. Characteristics of star-block copolymers were controlled by fraction, molecular weight and topology of the soft segment. Copolymers were prepared with varying soft segment ratio from 5.3 to 55.4 wt% and Tm of soft segment is adjusted between 28.9 and 55.6 °C. PtBA based copolymers with enhanced hydrophilicity (from 86.3 to 57.6°) exhibited Tm based shape memory behavior around body temperature with good shape recovery (Rr = 98.5%) and shape fixity (Rf = 98%).

中文翻译：

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聚（丙烯酸叔丁酯）基星形嵌段共聚物在生理范围内的热触发形状记忆行为

摘要 合成了一系列基于聚丙烯酸叔丁酯 (PtBA) 的星形嵌段共聚物，以获得具有体温触发的物理交联形状记忆聚合物 (SMPs)。首先，通过原子转移自由基聚合（ATRP）制备 PtBA 星形聚合物以形成硬链段。然后将星形聚合物用作大分子引发剂 (MI)，并与聚乙二醇 (PEG) 的线性/非线性衍生物结合，构建软链段。星形嵌段共聚物的特性受软链段的分数、分子量和拓扑结构控制。共聚物的软链段比例从 5.3 到 55.4 重量％不等，软链段的 Tm 在 28.9 到 55.6°C 之间调整。基于 PtBA 的共聚物具有增强的亲水性（从 86.3 到 57.