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活性聚合具有无终止、无转移、引发速率远远大于链增长速率等特点,是实现分子设计、合成具有特定结构和性能聚合物的重要手段。但常用的活性聚合方法如阴离子聚合、阳离子聚合、基团转移聚合等反应条件比较苛刻、适用单体较少,从而限制了它们的广泛应用。与之相对,自由基聚合具有反应条件温和、适用单体广泛、合成工艺多样、操作简便、工业化成本低等优点。但是,自由聚合存在与活性聚合相矛盾的基元反应或副反应(如自由基的偶合、歧化、转移反应等),使聚合过程难以控制。因此,自由基的活性聚合或可控聚合一直是高分子研究者努力探索的课题。1995年,旅美学者王锦山博士在卡内基-梅隆大学首次提出了原子转移自由基聚合(Atom Transfer Radical Polymerization,ATRP)。它是以简单的有机卤化物为引发剂、过渡金属配合物为卤原子载体,通过氧化还原反应,在活性种与休眠种之间建立可逆的动态平衡,实现了对聚合反应的控制,从而实现了活性聚合的重大突破。ATRP方法具有反应速度快、反应温度适中、适用单体范围广、可以在少量氧存在下进行以及分子设计能力强等特点,是一种很有生命力和竞争力的活性自由基聚合,已广泛用于结构可控、性能可调聚合物材料的设计合成中。
Living polymerization has the characteristics of no termination, no transfer, and the initiation rate is far greater than the chain growth rate. It is an important means to realize molecular design and synthesis of polymers with specific structure and properties. However, the commonly used living polymerization methods such as anionic polymerization, cationic polymerization, radical transfer polymerization reaction conditions are harsh, less applicable monomers, thus limiting their widespread use. In contrast, radical polymerization has the advantages of mild reaction conditions, suitable for a wide range of monomers, a variety of synthetic processes, easy operation, low cost of industrialization. However, there are radical reactions or side reactions (such as free radical coupling, disproportionation, transfer reaction and the like) which are incompatible with living polymerization in the free-radical polymerization, making the polymerization process difficult to control. Therefore, the living radical polymerization or controlled polymerization has always been the subject of polymer researchers to explore. In 1995, Dr. Wang Jinshan, a visiting scholar in the United States, first proposed Atom Transfer Radical Polymerization (ATRP) at Carnegie Mellon University. It is a simple organic halide as initiator, the transition metal complex as a halogen atom carrier, through the redox reaction, in the active species and dormancy species to establish a reversible dynamic equilibrium between the realization of the polymerization reaction in order to achieve A major breakthrough in living polymerization. ATRP is a very viable and competitive living radical polymerization with its fast reaction rate, moderate reaction temperature, wide range of suitable monomers, its ability to be carried out in the presence of a small amount of oxygen and its strong molecular design. It has been widely used In the structure of controllable, adjustable performance of polymer materials design and synthesis.