By introducing strong directed hydrogen bonds to an amphiphilic polymer, we demonstrate that phase transitions from spherical to cylindrical morphologies in aqueous solutions can significantly be shifted to favor the assembly of supramolecular polymer bottlebrushes. In water, a forced self-assembly of polymers into cylindrical structures remains a challenge as the often required hydrophobic shielding induces forces, which tend to minimize the surface area. The herein presented novel benzene trisureas can overcome these limitations due to strong hydrogen bonds and alter the morphology to cylinders despite an unfavorable packing parameter, which dominated the previously reported trisamide analogues. The systematic variation of composition and architecture revealed that a transition to spherical morphologies still occurs, but the phase-transition boundaries appear to be shifted to tolerate larger hydrophilic polymer chains. The strength of the directing interactions appears to be decisive for the shift, though we additionally observed that any restrictions of lateral aggregation can diminish the effect of the directing hydrogen bonds. Overall, the straightforward synthesis and versatile design render the presented systems an interesting blueprint for the development of more advanced supramolecular polymer bottlebrushes and multifunctional nanostructures.

To realize high-performance thermoplastic camera lenses for compensating chromatic aberration in which lenses with large and small Abbe numbers were combined, novel poly­(phenylene thioether)­s with a fluorene-based cardo structure were developed with the potential for simultaneously realizing high transparency, a high refractive index, low birefringence, and small Abbe number. Excellent transmittance was observed in all polymer films because the interchain packing was effectively suppressed by the cardo structure (e.g., transmittance was as high as 90% at 400 nm), and furthermore, high refractive index values (1.6553–1.6762) were attained. The polymer with the highest content of cardo structure exhibited a low birefringence of 0.0014. The efficient cancellation of polarization anisotropy between the polymer backbone and the fluorene units directed perpendicular to the polymer backbone contributed to the low birefringence. These results indicate that promising materials for high-performance optical applications can be developed based on the well-suited incorporation of the cardo structure into the polymer backbone.

No abstract

The development of a π-conjugated polymer with hydrogen-bonding moieties has aroused great attention because of the improved molecular stacking and the hydrogen-bonding network. In this study, PDPPTVT (diketopyrrolopyrrole-thiophenevinylenethiophene) and PDPPSe (diketopyrrolopyrrole-selenophene) alkylated with a carbosilane (SiC8) side chain and poly­(acryl amide) (PAM)-incorporated alkyl side chain were prepared, and their structure–performance and structure–stretchability correlation were evaluated. By incorporating the DPPTVT backbone and 0, 5, 10, or 20% PAM-incorporated alkyl side chain, the μh value could reach 2.0, 0.97, 0.74, and 0.42 cm2 V–1 s–1, respectively (P1 to P4). The polymer with the PDPPSe backbone and 5% PAM-incorporated alkyl side-chain (P5) exhibited the maximum μh value of 0.96 cm2 V–1 s–1. By extending the PAM moiety from the backbone with alkyl spacers, the solid-state packing and edge-on orientation can be properly maintained. Surprisingly, the PAM-incorporated alkyl side-chain can provide a hydrogen-bonding network serving as sacrificial bonding to mechanical deformation. Therefore, the relevant changes in the crystallographic parameters including the crystalline size and the in-plane π–π stacking distance with a 100% external strain were less than 4 and 0.8%, respectively, from P1 to P3. Therefore, P3 achieved an excellent stretchability while maintaining its molecular orientation and charge-transporting performance. Even with 100% external strain, P3 still provided an orthogonal μh over 0.1 cm2 V–1 s–1. Moreover, by substituting the TVT moiety with the Se moiety, the ductility of the backbone can be further increased when the elastic modulus decreases from 0.80 to 0.36 GPa for P2 to P5. The achieved high μh retention is over 20% after 500 stretching–releasing cycles with a 60% external strain perpendicular to the channel direction for the polymer composed of PDPPSe and 5% PAM content. The results manifest that our newly designed DPP with the PAM-incorporated alkyl side chain provides a promising approach to promote the intrinsic stretchability of the π-conjugated polymers.

High-refractive-index (high-n) polymers with a high optical transparency and low birefringence (Δn) have been desired in progressive optoelectronic devices. However, the trade-off between high-n and low-Δn remains a challenge at present. Here, the development of a novel array of high-n, high-sulfur-containing, highly transparent, colorless poly(phenylene sulfide) (PPS) polymers bearing triazine units in the main chains is reported. Six new triazine monomers T1−T6 with various pendant groups via different linkers (−O− and −NH−) could be prepared for developing PPSs with high-n and low Δn values. These PPSs (P1−P6) were obtained by the polycondensation of T1−T6 with commercial aromatic dithiol, 4,4′thiobisbenzenethiol, respectively, which showed very high-n values (n av : 1.6902−1.7169 at 633 nm), high optical transparency (T % > 90% @ 400 nm), and low birefringence (Δn = 0.0015−0.0042). All the PPSs displayed high n ∞ values (1.6340−1.6654), providing valuable information for the development of high-n triazine-based PPS materials for application not only in the visible region but also in the near-infrared region.