ma9b01103_si_001.pdf (1.22 MB)
Effect of Macromonomer Branching on Structural Features and Solution Properties of Long-Subchain Hyperbranched Polymers: The Case of Four-Arm Star Macromonomers
journal contribution
posted on 2019-08-22, 18:37 authored by Nairong Hao, Ahmad Umair, Mo Zhu, Xiaozheng Duan, Lianwei LiFollowing our recent work on AB3 macromonomer systems
(Macromolecules, 2019, 52, 1065–1082), this work focuses on AB4 systems
to further explore the effect of macromonomer branching on structural
features and solution properties of long-subchain hyperbranched polymers
(LHPs). Compared with ABn macromonomers
(n < 3), our results reveal that AB4 macromonomers tend to undergo less interchain coupling but more
intrachain self-cyclization during “click” polyaddition
process. Via the triple-detection SEC characterization of resultant
LHPs, both intrinsic viscosity ([η]) and radius of gyration
(Rg) are found to be scaled to the macromonomer
molar mass (Mmacro) and the total molar
mass (Mhyper) as [η]=Kη,AB4MhyperνMmacroμ (ν
≈ 0.40, μ ≈
0.25, and Kη, AB4 ≈ 1.72 × 10–2 mL/g) and Rg=HR,AB4MhyperαMmacroβ (α ≈ 0.52, β
≈
0.20, and HR, AB4 ≈ 1.54 × 10–3 nm). The obtained
results clearly demonstrate that (i) the self-similar behavior of
LHPs is almost independent of the detailed structures of the macromonomer
(AB2, AB3, and AB4) and (ii) the
AB4 system presents Mmacro-dependent
solution properties (μ ≈ 0.25 and β ≈ 0.20),
which is similar to the result for the AB2 system but totally
different from the observed Mmacro independence
for the AB3 system (μ ≈ 0 ≈ β).
A combination of experimental observation and Langevin dynamics simulation
of ABn dendrimers and LHPs unambiguously
verifies our previously proposed conjecture; that is, the unique synergistic
effect of segment back-folding and segment interpenetration exists
only in moderately branched LHP systems but not in highly branched
ABn LHP systems (n >
4).
History
Usage metrics
Categories
Keywords
AB n dendrimersAB 3 macromonomer systemstriple-detection SEC characterizationLong-Subchain Hyperbranched PolymersAB 4 systemAB 4 macromonomersLangevin dynamics simulationM macroAB 2 systemAB 4 systemsAB n macromonomersFour-Arm Star Macromonomerslong-subchain hyperbranched polymersM macro independenceAB n LHP systemsmacromonomer molar mass
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC