Room Temperature Fluorescent Conjugated Polymer Gums

Abstract

High molecular weight poly(diphenylacetylene) [PDPA] derivatives are introduced as fluorescent, soft conjugated polymers that exist in the gum state at room temperature. The gum‐like behavior of the polymers is easily modified according to the side alkyl chain length and substitution position. Long alkyl chain‐coupled PDPA derivatives provide soft and sticky gums at room temperature. Manual kneading of gum polymers produce soft films with very smooth surfaces. The gum polymers show an endothermic transition due to the melting of long alkyl chains. The X‐ray diffraction of gum polymers reveals a new signal due to the molten aliphatic chains. The gum polymers show significant viscoelastic relaxation at the melting temperature of the alkyl side chains. The dynamic thermo‐mechanical analysis (DTMA) of gum polymers at room temperature suggest that the meta‐substituted polymer is softer and stickier than para‐polymer. Rheological analysis suggests that the meta‐polymer has less entanglement than para‐polymer. The fluorescence emission of gum polymer is quite intense in the film and solution. The gum polymer film is readily stretched to produce a uniaxually oriented film. Stretching and subsequent relaxation of elastomer‐supported gum polymer film generate buckles perpendicular to the axis of strain. The gum polymer film accommodates the large strain without cracking and delamination.

Phase-change hybrids for thermo-responsive sensors and actuators

“…A covalently OD H − -coupled PDPA derivative (PDPA C18 in Figure 1) synthesized in a previous study 34,35 exhibited an endothermic transition at a much lower temperature of − 1°C, with a very low Figure 3d). This finding most likely results from the side OD H groups being covalently attached to the highly twisted backbone, leading to significantly weakened intermolecular forces, a longer intermolecular distance and a disordered structure between the side alkyl chains.…”

“…The observed FL enhancement is attributed to the degeneration of nonradiative emission decay channels of PDPA C1 , which occurred because of the relaxation of intramolecular π-stacking on the side-group phenyl rings resulting from the plasticizer effect of OD H . [33][34][35][36] However, the ultraviolet − Figure 2 Characterization of PCH films. (a) FL images, (b) FL emission spectra (excited at 420 nm), (c) FT-IR spectra, (d) TGA thermograms and (e) X-ray diffraction patterns of PCH films.…”

“…[28][29][30][31][32] Notably, the intramolecular stack structure of the side-group phenyl rings in PDPAs is fully relaxed in the swollen state, and consequently, the fluorescence (FL) emission of PDPAs can be strongly enhanced. [33][34][35][36] Furthermore, the degree of FL increase differs significantly based on the viscosity of the diffused medium because the degree of torsion angle relaxation of the side phenyl rings is affected by the friction energy transferred from the medium to these phenyl rings. 37 Accordingly, PDPA derivatives would be potential porous organic matrices for PCMs and also exhibit an optical sensory response, as required in the present work.…”

Effects of Molecular Structure and Packing Order on the Stretchability of Semicrystalline Conjugated Poly(Tetrathienoacene‐diketopyrrolopyrrole) Polymers

“…[18][19][20][21][22][23][24][25][26][27][28][29] Polymers with branched alkyl side chains have been reported with lower fracture strain than those with linear alkyl side chains. [18][19][20][21][22][23][24][25][26][27][28][29] Polymers with branched alkyl side chains have been reported with lower fracture strain than those with linear alkyl side chains.…”

Properties, Functions, Chemical Transformation, Nano-, and Hybrid Materials of Poly(diphenylacetylene)s toward Sensor and Actuator Applications

“…Recently, our research group has developed very soft PDPA derivatives that exist in the gum state at room temperature. 90 The two polymers (p-C1-and m-C1-PDPAs) having short alkyl chains gave powders after mechanical grinding, while the two long alkyl chain-coupled polymers (p-C18 and m-C18-PDPAs) did not. The latter two polymers appeared as gums or caramels.…”