Dispersity control in atom transfer radical polymerizations through addition of phenylhydrazine

Abstract

Phenylhydrazine is an effective modifier for conventional ATRP syntheses, providing systematic control over the dispersity of polymers with unimodal molecular weight distributions.

Polymer Dispersity Control by Organocatalyzed Living Radical Polymerization

“…[7][8][9][10][11][12] However,p olymers with large values are occasionally desired for improved physical properties such as miscibility and processability,a nd the manipulation of in LRP is an important topic but still challenging. [16][17][18] However,t he attained large usually arose from inefficient control in LRP. [13][14][15] Thep olymers need to be prepared in multiple independent runs,a nd the blended polymers often have multimodal molecular weight distribution.…”

“…By optimizing the polymerization conditions such as catalyst loadings, initiators,temperatures,and additional chain-transfer agents, the was modulated at 1.1-2.0 in LRP. [16][17][18] However,t he attained large usually arose from inefficient control in LRP. Thus,t he obtained polymers hardly undergo further chain extension.…”

Deconstructing Oligomer Distributions: Discrete Species and Artificial Distributions

“…[34] However, explicit knowledge of the relative contribution of each chain length to the overall distribution could not be obtained owing to constraints in the availability of proper starting materials and adequateness of synthetic methods applied. [34] However, explicit knowledge of the relative contribution of each chain length to the overall distribution could not be obtained owing to constraints in the availability of proper starting materials and adequateness of synthetic methods applied.…”

Tuning Dispersity by Photoinduced Atom Transfer Radical Polymerisation: Monomodal Distributions with ppm Copper Concentration

“…[16][17][18] Perhaps the most traditional way to tailor the molecular weight distribution is to blend presynthesised polymer samples consisting of multiple molecular weights. [30,31] Other systems require the addition of as mall amount (4-10 %) of ad ifferent monomer type to efficiently tailor the dispersity,leading to random copolymers. [22,23] In addition, the groups of Boyer, Leibfarth, and others [24][25][26][27][28] exploited flow chemistry to successfully tailor the dispersity by adjusting reagent concentrations,p ump flow rates,v iscosity,a nd residence times.G oto and co-workers were also able to control molecular weight distributions through at emperature-selective metal-free organocatalysed living radical polymerisation system forming complex blocks,s tars,a nd brush polymers.…”

“…[30][31][32] Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF-MS) of highdispersity samples can be challenging,asthe samples contain abroad range of different species and ionising high molecular weight polymer chains can be problematic.F or example,due to the high dispersity of our samples,p art of the polymer population exceeds 75 000 gmol À1 according to SEC although the average M n is just % 12 500 gmol À1 .T ocircumvent this and assess the end-group fidelity of the high-dispersity materials, alower degree of polymerisation was also targeted (DP = 10, = 1.52, Figure S12). [30][31][32] Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF-MS) of highdispersity samples can be challenging,asthe samples contain abroad range of different species and ionising high molecular weight polymer chains can be problematic.F or example,due to the high dispersity of our samples,p art of the polymer population exceeds 75 000 gmol À1 according to SEC although the average M n is just % 12 500 gmol À1 .T ocircumvent this and assess the end-group fidelity of the high-dispersity materials, alower degree of polymerisation was also targeted (DP = 10, = 1.52, Figure S12).…”