Journal of Polymer Science Part A: Polymer Chemistry最新文献

A new medium bandgap polymer incorporating electron-rich 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (BDTT) and electron-deficient 2,3-didodecyl-6,7-difluoro-5,8-di(thiophen-2-yl)quinoxaline (2TffQ) units in an alternate manner, namely P(BDTT-2TffQ), was prepared for organic solar cell (OSC) applications. The optical and electrochemical properties of P(BDTT-2TffQ) were found to be suitable to use it as an electron donor in OSCs. The absorption band covers the region from 300 to 600 nm with an optical bandgap (E_g) of 1.84 eV, and it highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) were found to be positioned at −5.36 and − 3.52 eV. The OSCs prepared by using P(BDTT-2TffQ):[6,6]-Phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM) and P(BDTT-2TffQ):2,2′-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) blends provided a maximum power conversion efficiency (PCE) of 5.50% and 11.65%, respectively. The differences in the photovoltaic performances of OSCs are mainly attributed to their dissimilar short-circuit current (J_sc), which depends on their absorption spectrum. Herein, we also compared the properties of P(BDTT-2TffQ) with a structurally similar polymer, namely P(BDTT-2TfQ), made up of BDTT and 2,3-didodecyl-6-fluoro-5,8-di(thiophen-2-yl)quinoxaline (2TfQ) units, for better understanding the effects of the incorporation of additional fluorine atom on the backbone of quinoxaline-based polymers.

We synthesized the novel methacrylate monomer bearing an oxazolidone structure (M1) and performed radical polymerization of M1 by traditional procedures. The glass transition temperature (T_g) of the obtained polymer (P1) was a significantly high value compared to that of poly(methyl methacrylate) and typical poly(urethane methacrylate)s. The copolymers of M1 and monofunctional urethane methacrylate derived from 2-hydroxyethyl methacrylate and phenyl isocyanate (M2) exhibited a linear rise of the T_g values depending on the composition ratio of M1. The NMR analysis and the estimation of monomer reactivity ratio and Q–e values suggested that the improvement of glass transition temperature resulted from a stereoregularity, meaning a syndiotacticity of the copolymers improved with increasing the composition ratio of M1. Furthermore, the thermal curing reaction of M1 or M2 with bifunctional urethane acrylate successfully proceeded, then the T_g value of the cured product from M1 was much higher than that from M2.

Two-component catalysts composed of tetra (para-X substituted) phenylporphyrin aluminum (III) chloride, T (p-X-P)PAlCl, (where X = H, F, Cl, Br, CH₃, OCH₃, tert-butyl), and cocatalyst bis(triphenylphosphine)imminium chloride (PPN⁺Cl⁻), could initiate the polymerization of propylene oxide (PO). And they could react with rac-lactide, (rac-LA), in the presence of propylene oxide (PO), to yield chains of enriched isotactic polylactide (PLA) with trace polyether segment. Also, these catalysts displayed different catalytic activity in the copolymerization of CO₂ and PO, resulting in poly(carbonate-co-ether) copolymer with different carbonate unit content (CU%). Further, these catalysts could initiate one-pot regio- and stereo- selective terpolymerization of rac-LA, CO₂ and rac-PO, resulting in multi-blocky poly(carbonate-co-lactide) with trace polyether segment. The structure of the products was verified by ¹H NMR, ¹³C NMR, GPC, and DSC analysis, and it was found that variation of substitution groups in the periphery of porphyrin ligand would affect on the catalytic efficiency of ter-polymerization, and the relative polymerization reaction ratio of the ring-opening polymerization of LA (ROP) to the ring-opening copolymerization of PO and CO₂ (ROCOP), resulting in ter-polymer with different contents of PLA segment and PPC segment. However, H-T% in polycarbonate unit and P_i% in polylactide unit did not vary much with the change of catalysts.

Mechanical recycling is a decisive contribution for a sustainable circular economy of polypropylene (PP) but faces the challenge of processing-induced and use-phase accumulated molecular damage, exacerbated by multiple loop recycling. In this contribution, the molecular origin of degradation of PP under up to 30 repetitive reprocessing loops is analyzed together with the influence of stabilization, and processability data linked to changes of the entire molecular weight distribution. By comparison of experiments with simple Monte Carlo simulations, a coupled mechanism of random scission and shear-induced cleavage can be inferred, while stabilizing additives effectively protect the material from progressing along this combined degradation pathway.

Synthesizing soft polymers with uncommon architectural elements is critical for enhancing our understanding of fundamental structure–property relationships in macromolecules. Terpenoid materials are interesting candidates for addressing this grand challenge, as their constituent monomers can exhibit a diverse array of structural and functional groups. Moreover, these biologically-derived materials can potentially expand the sphere of knowledge surrounding trends in related petrochemically-derived polymers. For example, vinyl-addition copolymers of norbornene and acyclic olefins can exhibit predictable properties (e.g., linear changes in T_g as a function of composition). Due to synthetic limitations, however, it is not well understood if other rigid carbocycles engender similar behavior in a range of copolymers. As numerous terpene scaffolds display rigid motifs (such as pinane systems), terpenoid polymers are uniquely positioned to address this deficiency. Here, we report the synthesis and characterization of terpenoid copolymers (both statistical and block) with systematically tailored compositions of pinene-based comonomers. We found that the pinane core (which is a constitutional isomer of norbornene) appears to promote ideal behavior with regard to bulk thermal properties of statistical copolymers, which mirrors the behavior of norbornene-based systems. We also found that block copolymers exhibited thermomechanical properties that were highly tunable (and apparently correlated to carbocycle composition).

The addition of small molecular plasticizer is an efficient strategy to increase the process ability and macroscopic performance of poly(vinyl alcohol) (PVA). However, how the plasticizer influences the chain dynamics and morphology deserves further investigation. In this work, the PVA film with varying glycerol addition levels was used as the model system. The increasing glycerol addition-level results in the depression of the melting temperature and crystallization temperature, which in line with Flory's theory. The enhanced chain dynamics in the mobile domain was accessed by low-field NMR, whereas that in the crystalline region remains constant. The domain size as well as the morphology of the mobile phase are accessed by ¹H spin-diffusion NMR. The results indicate the increasing dimensionality of the plasticized PVA film with increasing the addition level of glycerol, where the addition level below 25 wt% leads to the dimensionality of 1D, and higher than 25 wt% results in the dimensionality of 2D. Current results elucidate the critical role of the plasticizer in modulating the dynamics heterogeneity of the plasticized polymer film, which is closely related to the macroscopic performance of the products.

A series of polyvinyl alcohol (PVA) composite films containing different hydrogen bond acceptors 4,4′-dihydroxydiphenyl (BP), 1,1′-biphenyl-4,4′-diyl dihexanoate (DHB) and benzene-1,3,5-triyl tribenzoate (TBB) were prepared by casting method. Due to the existence of strong intermolecular interaction, the highest in-plane thermal conductivity of the above films is 1.298 Wm⁻¹ K⁻¹, which is about 65% higher than pure PVA films. Fourier Transform infrared spectroscopy (FT-IR) and wide-angle X-ray diffraction (WXAD) demonstrated that the TBB acts as a thermal bridge to enhance the internal interaction force and make the internal structure more regular. Strong molecular contact forces were demonstrated by mechanical tensile testing. The thermal expansion rate of the system was explored through molecular dynamics. Thermal expansion experiments proved that hydrogen bond can effectively reduce the free volume. Molecular dynamics simulations were also performed in this work. The number and density of hydrogen bonds inside different polymers were calculated, and the phonon thermal transport was quantitatively analyzed. The thermal bridge and intermolecular contact force were discovered to effectively restrict the molecular chain's activity and reduce its free volume. The results of the experiments and molecular dynamics reveal that strong intermolecular interactions and thermal bridges can significantly improve polymer intrinsic thermal conductivity.

The design of compartments capable of carrying out biological reactions in a local space has provoked enormous interest by providing spatiotemporal and long-term selective control of biological activity. On the other hand, the application of metal-porphyrins in the field of biomedical science as nanozymes is gaining substantial importance. Porphyrins are the most widely studied tetrapyrrole-based compounds because of their important roles in vital biological processes and they possess peculiar photochemical, photophysical, and photo/redox properties. Herein, we demonstrate the use of pH-responsive and photo-crosslinked polymersomes for loading β-cyclodextrin-Hemin complexes as potential peroxidase-mimicking cavity. The loading of catalytic active centers into polymeric vesicles represents a simple and effective strategy for enzyme mimicry. Physicochemical and enzyme-like properties are studied using a variety of characterization methods at different simulated microenvironments. This work offers an improvement of the aqueous solubility of the Hemin molecule, crucial for biomedical applications. In addition, these nanocompartments can be used as artificial radical-producing and hydrogen peroxide-consuming organelles, being able to replace cell functions in different microenvironments. Therefore, these artificial organelles, entrapping nanozymes, could provide promising synergistic and more personalized therapies on demand in modern nanomedicine.

Welcome to this special issue of the Journal of Polymer Science, celebrating the life and works of Professor Takuzo Aida on his 67th birthday. His journey starting from a small town in Oita to becoming a giant in the field of polymer science is truly inspiring. He is currently a Distinguished University Professor at the University of Tokyo, and a member of the U.S. National Academy of Engineering, the American Academy of Arts and Sciences, and the Royal Netherlands Academy of Art and Science. Through contributed works of friends and colleagues of Professor Aida, we aim to highlight the remarkable impact he has had in the field of polymer science. We hope that this special issue will not only honor the many incredible achievements of Professor Aida as a scientist, mentor, and visionary leader, but also encourage new generations of future scientists to follow in his footsteps and push the boundaries of scientific knowledge.

Professor Aida was born and raised in Oita, a beautiful part of the southern island, famous for its rugged mountains and stunning coastline in Japan. He attended Yokohama National University, majoring in Physical Chemistry, and received his B.S. degree in 1979. During his graduate studies, he worked under the tutelage of Professor Shohei Inoue at the University of Tokyo. After earning his Ph.D. in Polymer Chemistry in 1984, he remained at the university to begin his academic career. Early in his career, he went to the IBM Almaden research center in San Jose in 1989 as a visiting scientist. This experience was an eye-opening one for him: He witnessed major innovations happening at the intersection of science through collaboration of scientists. With a newfound vision, Professor Aida returned to Tokyo and established an open and collaborative research environment where ideas could be freely discussed and shared, and as we all know, many innovations in polymer science were made.

After returning to Tokyo, he was promoted to full professor in the Department of Chemistry and Biotechnology in 1996. Since then, he has led several of Japan's leading research projects, including the Japan Science and Technology Agency (JST)'s ERATO “AIDA Nanospace Project,” commenced in 2000, the ERATO-SORST project from 2005, and the Specially Promoted Research Program that began in 2013. He also served as the director of the RIKEN Advanced Science Institute from 2008 to 2012. Since 2013, he has been a Deputy Director of the RIKEN Center for Emergent Matter Science (CEMS). In 2022, he was appointed as a Distinguished Professor of the University of Tokyo.

At the forefront of the rapidly evolving field of polymer science, Professor Aida has made significant contributions to numerous facets of this field. He is most well-known for the development of supramolecular polymers, in which he played a major role in the initiation of the basic concept, conceptual expansion, and development of functional materials. Importantly, his work b

Polylactide (PLA) is a fully bio-derived polyester with great biodegradability, biocompatibility, and mechanical properties. Synthesis of stereoregular PLA by highly stereoselective organocatalyzed ring opening polymerization (ROP) of racemic lactide (rac-LA) at room temperature is challenging despite some important developments in the past few years. In this contribution, two bulky phenyl diphosphazene bases, p-PDPB and m-PDPB, were conveniently synthesized by the Staudinger reaction. In combination with different hydrogen-bond donors such as ureas and squaramides, they could mediate the stereocontrolled ROP of rac-LA in THF at room temperature. Semicrystalline PLAs with narrow dispersity and high tacticity (P_m up to 0.84) were successfully synthesized in a well-controlled manner using phenyl diphosphazene based/urea binary catalytic system. Structural analysis verified the linear structure and high end-group fidelity of the resulting polymers. Moreover, the minimal transesterification of the polymer backbone proved by the MALDI-TOF MS analysis indicated the good controllability of the phenyl diphosphazene based binary catalytic system.