It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly (n-butyl acrylate) viz. polystyrene-block-poly-(n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

已经观察到丙烯酸酯单体非常难以与低成本的硝基氧催化剂 2,2,6,6-四甲基哌啶基-1-氧基 (TEMPO) 聚合。因此，昂贵的无环氮氧化物如 N-叔丁基-N-(1-二乙基膦酰基-2,2-二甲基)-N-氧基、(SG1)、2,2,5-三甲基-4-苯基-3-氮杂己烷-3-硝基氧化物 (TIPNO) 和 TIPNO 衍生物必须用于丙烯酸衍生物的聚合。关于使用 TEMPO 衍生物进行丙烯酸正丁酯聚合的报道很少。通常不同的还原剂即。葡萄糖、抗坏血酸、羟基丙酮等已被用于在聚合反应过程中破坏过量的 TEMPO。由于丙烯酸酯链末端和硝基氧之间形成的强 C-O 键，丙烯酸酯聚合在 TEMPO 存在下失败。据我们所知，没有关于使用不含还原剂或高温引发剂的 TEMPO 进行丙烯酸正丁酯聚合的文献报道。本研究旨在重新审视低成本氮氧化合物 TEMPO 的应用，以便将其用于丙烯酸酯单体（例如丙烯酸正丁酯）的聚合。我们已经能够聚合n-使用硝基氧 TEMPO 作为引发剂（通过大分子引发剂）的丙烯酸丁酯。在该合成中，聚苯乙烯大分子引发剂在第一步中由 TEMPO 合成，此后该 TEMPO 封端的苯乙烯大分子引发剂 (PSt-TEMPO) 用于聚合丙烯酸正丁酯单体。大分子引发剂的用量为n-重量的 0.05% 至 50%丙烯酸丁酯单体。通过本体聚合法在120℃下进行聚合。实验结果表明，随着 PSt-TEMPO 大分子引发剂用量的增加，形成的聚合物的分子量逐渐增加，而多分散指数 (PDI) 逐渐降低。在所有实验中，转化率均超过 80%。这些结果表明聚合是通过受控聚合过程进行的。还研究了不同溶剂对聚合的影响。在以下实验中，TEMPO 封端的苯乙烯已被用作大分子引发剂，从而成功合成了聚n-丙烯酸丁酯。已经发现苯乙烯大分子引发剂对于氮氧化合物介导的聚合是高效的，即使对于聚丙烯酸正丁酯的合成来说浓度非常低。高浓度的大分子引发剂导致聚苯乙烯和聚（丙烯酸正丁酯）嵌段共聚物的形成，即。聚苯乙烯-嵌段-聚-（丙烯酸正丁酯）。使用 TEMPO 进行受控聚合非常重要，因为它是市售的硝基氧，成本最低。