Hyperbranched poly(triazole) with thermal and metal ion dual stimuli-responsiveness

Abstract

Oligo(ethylene glycol)-terminated hyperbranched poly(triazole) (hb-PTA-OEG) with thermal and metal ion dual stimuli-responsiveness was synthesized by Cu(I)-catalyzed azide-alkyne cycloaddition polymerization, which possessed high molecular weight (M n = 203 kDa) and good thermal properties (T d = 367 o C, T g = -14.1 o C). Importantly, hb-PTA-OEG exhibited relative low cloud point (CP) temperature ranging from 34.4 to 31.1 o C as the concentration increasing from 0.02 to 2.0 wt%. Simultaneously, hb-PTA-OEG has the ability to coordinate various metal ions, and the type of metal ions influenced the CP of hb-PTA-OEG solution in some extent as a result of their different association strengths with polymer, particularly, Ag + ion showed a conspicuous contribution to increasing the CP among the selected several ions. In consequence, hb-PTA-OEG can act as an absorber of metal ions, and the selective absorption of Ag + ion could be reached by tuning the temperature. KEYWORDS: Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC); hyperbranched poly(triazole); thermal responsiveness; metal ion responsiveness; Ag + ion. The hyperbranched poly(triazole) (hb-PTA) with high molecular weight (M n = 154 kDa) and relatively narrow molecular weight distribution (M w /M n = 1.45) (Fig. S1, ESI †) was firstly achieved from AB 2 -type monomer M1 via CuAAC using the catalyst system of sodium ascorbate and CuSO 4 ·5H 2 O (Scheme 1), which is purer than copper(I) salt, 21 and was then transformed into the hyperbranched poly(triazole) bearing OEG groups (hb-PTA-OEG) by the end-capping modification, accompanying with the increase of molecular weight (M n = 203 kDa, Fig. S1, ESI †). Scheme 1 Syntheses of M1, hb-PTA, and hb-PTA-OEG.The polymers were roughly characterized by IR spectra (Fig. 1), the emergence of the triazole absorption peak at 3145 cm -1 and disappearance of the yne group absorption peak at 3290 cm -1 are indicative of the formation of hb-PTA and hb-PTA-OEG, respectively. The polymer structure was further confirmed by 1 H and 13 C NMR spectroscopy. After CuAAC polymerization, the peak of acetylenyl proton of M1 at 2.04 ppm (Fig. 2a) disappeared, while some new peaks were observed in the 1 H NMR spectrum of hb-PTA (Fig. 2b). For example, the peaks at 7.6 and 4. 26-4.15 ppm should be ascribed to the signals of the newly formed triazole ring protons and the methylene protons connected to the nitrogen atom of triazole, respectively. As ) for financial supports of this work. †Electronic Supplementary Information (ESI) available: Synthesis and characterization of model compound 4, GPC curves, thermogravimetric analysis, differential scanning calorimeter curves, transmittance, and solubility of polymers. See

Metathesis cyclopolymerization of substituted 1,6‐heptadiyne and dual conductivity of doped polyacetylene bearing branched triazole pendants

“…S1 and S3) and HR‐MS characterizations demonstrated their successful synthesis. The initial purpose was acquiring BTA with controllable structure and low molecular weight ( M n ) via click chemistry of AB 2 ‐type monomer 2 , to act as the pendant groups of PA. Several attempts were conducted, however, all the explorations were failed due to the high reactivity of 2 , which tends to readily form the hyperbranched poly(triazole) with high M n whatever varying the concentration, temperature, or the reaction time . Another approach of slow monomer addition to a core was then tried, which was demonstrated to be a preferential method for the controlled synthesis of well‐defined hyperbranched polymer .…”

“…LiTFSI was purchased from Shanghai Dibo Chemical Reagents Company. 3,5‐Cl 2 Py was purchased from Tokyo Chemical Industry Co. Ltd 2‐(2‐azidoethoxy)ethyl 2‐(prop‐2‐ynyl)pent‐4‐ynoate ( 2 ), azido‐2‐(2‐(2‐methoxyethoxy)ethoxy)ethane (OEG‐N 3 ), 4‐hydroxymethyl‐1,6‐heptadiyne, 4‐carboxyl‐1,6‐heptadiyne, and Ru‐III were prepared according to the literatures. Solvents were distilled over drying agents prior to use: dichloromethane (CH 2 Cl 2 ) from calcium hydride.…”

“…Except for the EO segments, the nitrogen‐containing groups have also the ability to solvate Li + , hence could be benefit for Li + transport as well. Triazoles, very important nitrogen heterocyclic compounds, have been widely researched due to their easy and flexible modification . Motivated by these observations above, herein, the short oligo(ethylene glycol) (OEG) segment‐modified branched triazole ( BTA ) group was introduced into 1,6‐heptadiyne to get the monomer for MCP, aiming to synthesize PAs with modified solubility, enhanced stability, and improved conductivity.…”

Synthesis of a New Polyanion Possessing Dense 1,2,3-Triazole Backbone

“…1,2,3-Triazole is an aromatic five-membered ring consisting of two carbon and three nitrogen atoms with a large dipole [ 7 , 8 ], which acts as an interaction site through hydrogen bonding, coordination bonding, dipole–dipole interaction, and π–π stacking [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. 1,2,3-Triazoles are readily formed from azide and alkyne functionalities through 1,3-dipolar cycloaddition [ 7 , 15 , 16 , 17 ].…”

Emission Properties of Diblock Copolymers Composed of Poly(ethylene glycol) and Dense 1,2,3-Triazole Blocks

“…Some examples have been reported on functional polymers containing 1,2,3-triazole units. Polymer-carrying 1,2,3-triazole moieties can be utilized for gelation [16], sensing [17], and control of clouding point [18] through coordination bonding and solubility control [14], controlled release [19], and tough network polymer [20] through π–π stacking. Therefore, polymers composed of denser 1,2,3-triazole moieties are highly promising for new functional polymers that exhibit characteristic interactions or associations.…”