Synthesis of a New Stable β-Sulfinyl Nitroxide and the Corresponding Alkoxyamine for Living/Controlled Radical Polymerization of Styrene: Kinetic and ESR Studies
作者:Eric Drockenmuller、Jean-Marie Catala
DOI:10.1021/ma011063k
日期:2002.3.1
corresponding N-β-sulfinyl alkoxyamine are reported. Styrene was polymerized in bulk in the presence of this new alkoxyamine. The polymerization satisfies the usual criteria of a living/controlled radical polymerization, with a linear increase of molecular weight vs yield and a constant transient radical concentration with time. However, the polymerization rates were independent of alkoxyamine concentration but
报道了在β-位(相对于氮)具有亚砜基的新的氮氧化物和相应的N -β-亚磺酰基烷氧基胺的合成。在这种新的烷氧基胺的存在下,苯乙烯大量聚合。该聚合反应满足活性/受控自由基聚合反应的通常标准,分子量与产率成线性增加,并且随时间变化的瞬态自由基浓度恒定。但是,聚合速率与烷氧基胺浓度无关,但远高于热聚合速率: R p / R th在90°C下为2.6,在100°C下为3.7和在110°C下为3.5。动力学和ESR研究表明,瞬态和持久性自由基浓度均不随时间变化而遵循相应的理论演化,而是达到稳态。不同的速率常数(ķ d和ķ Ç)和相应的活化能估计,表示亚砜基团具有主要是对组合反应有很大的影响,其值是这样的系统(不寻常的低ķ Ç ≈10 5大号mol -1 s -1)。