Universal Synthetic Strategy for the Construction of Topological Polystyrenesulfonates: The Importance of Linkage Stability during Sulfonation

Abstract

Polystyrenesulfonate (PSS), as one of the most important categories of polyelectrolytes, has received increasing attention due to its great potential in the applications of energy-and biomedical-related fields. However, most of the previous studies only focused on linear PSS and its derivatives, but little attention was paid to nonlinear topological PSSs. So far, the synthesis of nonlinear PSSs with well-defined structures is still a challenging task, and the main obstacle lies in the stability issue of functional chemical linkages during the sulfonation process of polystyrene (PS) precursors, such as the carbon−oxygen-containing linkages. Herein, by rationally designing the chemical structure of the functional linkage, we introduce a versatile and efficient strategy for the preparation of topological PSSs. Specifically, by embedding firm triazole linkages (without carbon−oxygen linkages) into the backbone structure of cyclic and hyperbranched PS precursors, the backbone and functional linkages are found to present excellent chemical stability under certain sulfonation conditions, which eventually lead to the successful preparation of cyclic and hyperbranched PSSs. By using two sets of PSS samples with varied molar masses, the scaling relations between the number of repeating units and the sedimentation coefficient are established for both linear and cyclic PSSs. We believe that our proposed synthetic strategy is universal and could be extended to the synthesis of other types of topological PSSs.

Preparation of Functional Long‐Subchain Hyperbranched Polystyrenes via Post‐polymerization Modification: Study on the Critical Role of Chemical Stability of Branching Linkage

“…[29,30] It is worth mentioning that in our recent work, AB 2 hyperbranched polystyrenesulfonate were successfully synthesized by soft sulfonation with acetyl sulfate as the the sulfonating reagent, using AB 2 hyperbranched polystyrene with total carbon branching linkage as the precursor. [31] The results clearly prove that the total carbon branching linkage has an incomparable stability advantage over ester linkage under the condition of sulfonated PPM, indicating that the stability of the branch point in the PPM process is very important.…”

“…N,N,N',N',N''-pentamethyl-diethylenetriamine (PMDETA, Aldrich, 99 %), Tris(2-(dimethylamino)ethyl)amine (Me 6 TREN, Aladdin, 98 %), 2,2'-bipyridine (bpy, Fluka, 99 %), 4,4'-ditert-butyl-2,2'-dipyridyl (dt-bpy, Aldrich, 98 %), tin(II) 2-ethylhexanoate (Sn(EH) 2 , Aladdin, 95 %), sodium azide (NaN 3 , Aldrich, 99 %), phenylacetylene (Aladdin, 97 %), boron tribromide (BBr 3 , Aladdin, 1.0 M in methylene chloride), sodium hydroxide (NaOH, Sinopharm, AR), trifluoroacetic acid (TFA, Energy Chemical, 99 %), lithium aluminum hydride (LiAlH 4 , Sinopharm, 97 %) and methanol (Sinopharm, 99.8 %) were used as received. Propargyl 2,2-Bis((2'-bromo-2'-methylpropanoyloxy)methyl)propionate (PBMP, ester-type) [26] , 1,3-dibromomethyl-5-propargyloxy-benzene (DBMPB, aryl-ethertype) [27] and 1,3-bis(bromomethyl)-5-ethynylbenzene (BBMEB, carbon-carbon-type) [31] was prepared according to our previously published procedure.…”

“…Long‐subchain hyperbranched polymers (LHPs) with long linear chains between every two branching points have received considerable attention in the past two decades, since it can combine the excellent mechanical properties of linear polymers with the special physical properties of hyperbranched polymers. Three main methods have been reported to synthesize LHPs: (1) A 2 +B 3 approach, (2) self‐condensing vinyl polymerization (SCVP) approach, and (3) macromonomer AB n approach . In vein of the A 2 +B 3 approach, Long et al.…”

“…Three main methods have been reported to synthesize LHPs: (1) A 2 + B 3 approach, [20,21] (2) self-condensing vinyl polymerization (SCVP) approach, [22,23] and (3) macromonomer AB n approach. [24][25][26][27][28][29][30][31][32] In vein of the A 2 + B 3 approach, Long et al synthesized a series of LHPs such as hyperbranched poly(ether ester)s, and polysulfone ionomers by polycondensation of an A 2 chain and a B 3 monomer. [21] Alternatively, Gao et al [22] synthesized hyperbranched poly(tertiary amino methacrylate)s with hydrophilic core and hydrophobic shell via SCVP methodology.…”

Characterization of mixed solutions of hyperbranched and linear polystyrenes by a combination of size‐exclusion chromatography and analytical ultracentrifugation

“…[18] In addition to liquid chromatography, analytical ultracentrifugation (AUC) is also a good tool for separation of solutes based on the molar mass and the size of the solutes in solutions. [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] It has been widely used to characterize polymers and nanoparticles, [19][20][21][22][23][24][25][26] proteins, [27][28][29][30] and DNA. [31][32][33][34][35] However, only a few research studies have been done to characterize polymers by a combination of SEC and AUC.…”