Hydrazine as a Nucleophile and Antioxidant for Fast Aminolysis of RAFT Polymers in Air

Abstract

The bifunctional role of hydrazine as a potent nucleophile and antioxidant was investigated for the rapid aminolysis of RAFT polymers within minutes in air with effective suppression of the formation of disulfides. Using both dithioesters and trithiocarbonates as model compounds, we showed that hydrazine exhibited a significantly improved aminolysis rate when compared with a commonly used primary alkyl amine. On the basis of the exellent results with CTAs, we further studied the aminolysis of RAFT polymers prepared with either dithioesters or trithiocarbonates. In accord with the aminolysis results on CTAs, hydrazine aminolyzed RAFT polymers in an impressively short time and, more importantly, it significantly suppressed the formation of disulfides as comfirmed with GPC.

Living Radical Polymerization by the RAFT Process – A Third Update

“…[34] It has been reported that the use of hydrazine as nucleophile is advantageous both in giving a very rapid reaction and little disulfide formation even when the process was carried out in air. [375] However, Lee et al [176] found disulfide formation to be significant during the hydrazinolysis of St/AcS copolymers. DADMAC [113,440] N Cl Ϫ 427 [589] O OC(CH 3 ) 3 OC(CH 3 ) 3 O O 428 [590] O O O O 429 [590] O O O O n 430 [591] O O…”

“…[44] The first reports involved the use of N,N-dialkyl dithiocarbamate derivatives as ATRP initiators. Dithiocarbamates do not provide effective control over the polymerization [241] MMA, St 456 Propylamine Network cleavage [603] BA, St 441 Butylamine/TCEP/BA In situ thiol-ene multiblock cleavage [604] PEGA 47 Butylamine/TCEP/divinyl sulfone In situ thiol-ene [281] MA, DMAm, NIPAm, St, C 2 H 5 S (121) Hydrazine - [375] St, PEGMA Ph (54, 18) Hydrazine - [375] St Ph (18) Hydrazine Used in thiol-epoxide [193] St Ph (18) DEAm (18) Hydrazine In situ thiol-epoxide [193] St/AcS Ph (11) Hydrazine Au nanoparticles [176] EGDMA, 421, 420 Ph (18) Hexylamine Used in thiol-ene or other reaction [588] St PhCH 2 S 1) KOH, 2) Zn/AcOH Au nanoparticles [338] St PhCH 2 S (89) Ethylene diamine Initiator for ROP C [339] HPMAm Ph (11) NaBH 4 /PBu 3 In situ thiol-ene (AA) [161] HPMAm Ph (68) Butylamine MeOH/degassed used in thiol-ene [307] NIPAm Ph (18) NaBH 4 Used in thiol-ene [247] MMA Ph (18) Hexylamine In situ thiol-ene [220] HPMAm Ph (18) Hexylamine In situ thiol-ene [220] NIPAm CH 2 (CO 2 H)CH 2 S (179) Hexylamine In situ thiol-ene [220] NIPAm C 4 H 9 S (159) Hexylamine/DMPP Used in thiol-ene [446] NIPAm C 12 H 25 S (123) Hexylamine/Bu 3 Ph Used in thiol-ene [398] Am Ph (18) NaBH 4 Used in thiol ene [244] DEAm Ph ( StMe OEt Ozone --(C¼O)SOEt [606] BA OEt Ozone --(C¼O)SOEt [607] iBoA 2-pyridyl Air AIBN, THF/Ph 3 P -OH [605] MMA, acrylates Ph Air AIBN, THF/Ph 3 P -OH [182,605] St, acrylates P n S Air AIBN, THF/Ph 3 P -OH [182] MA, BA CH 2 Ph Air AIBN, THF/Ph 3 P -OH [182] St CH 2 Ph Air AIBN, THF/Ph 3 P -OH …”

“…HPMAm [379] 119 PEO macro-RAFT agent [380] APMAm [380] APMAm-b-NIPAm [380] 120 PEO macro-RAFT agent [381] St [381] (Continued ) [375] (412) [243] DMAm [375] DMAm [326] DMAm [326] St [375] NIPAm [375,382] DMAm-b-370-b-365 [383] CO 2 H…”

Combining RAFT Radical Polymerization and Click/Highly Efficient Coupling Chemistries: A Powerful Strategy for the Preparation of Novel Materials

“…Indeed, such end-groups are easily converted under a range of conditions including aminolysis, [107,108] hydrazinolysis, [109] and hydride [110] cleavage with aminolysis being the preferred route. [105] Reactions can be conducted such that the macromolecular thiol is generated in situ and used in a subsequent reaction in a one-pot process, the thiol may be trapped or in some instances the macromolecular species can be isolated and characterized prior to use in a subsequent step.…”

Tailoring Confinement: Nano-Carrier Synthesis via Z-RAFT Star Polymerization

“…Under UV-irradiation of appropriate wavelength, the cross-linking reaction of the outer region is carried out. Finally, the RAFT-core is decomposed via aminolysis [28] to achieve hollow sphered particles. The success of the procedure is monitored by size exclusion chromatography (SEC)-measurements of the material after the different steps of synthesis as well as by dynamic light scattering (DLS).…”