A block copolymer consisting of functional polynorbornene and polyacetylene segments was self-assembled into a superhelical nanotube, and displayed good dielectric properties.

A new type of insulating-conductive block copolymer was synthesized by metathesis polymerization. The copolymer can self-assemble into unique nanostructures of micelles or hollow spheres. It exhibits a high dielectric constant, low dielectric loss, and high stored/released energy density due to the strong dipolar and nano-interfacial polarization contributions.

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

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