Catalytic amounts of sodium hydroxide as additives for iron-mediated AGET ATRP of MMA

摘要

The atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of methyl methacrylate (MMA) in the presence of catalytic amounts of sodium hydroxide (NaOH) was studied to examine the function of NaOH in this system, using ethyl 2-bromoisobutyrate (EBiB) as the initiator, oxidative FeCl3·6H2O as the catalyst, tris-(3,6-dioxa-heptyl)amine (TDA-1) as the ligand, glucose as the reducing agent, and tetrahydrofuran (THF) as the solvent at 90 °C. The polymerization rate can be increased significantly while keeping good controllability over molecular weights and molecular weight distributions. For example, the polymerization rate of solution AGET ATRP with a molar ratio of [MMA]0/[EBiB]0/[FeCl3·H2O]0/[TDA-l]o/[glucose]0/[NaOH]0 = 500/1/1/3/ 1/1.5 in the presence of a limited amount of air with NaOH was 1.6 times faster than that without NaOH and kept low molecular weight distribution (M_W/M_n < 1.35).