Functional Polymeric Materials Research Articles

CASTING: A Potent Supramolecular Strategy to Cytosolically Deliver STING Agonist for Cancer Immunotherapy and SARS-CoV-2 Vaccination

CASTING: A Potent Supramolecular Strategy to Cytosolically Deliver STING Agonist for Cancer Immunotherapy and SARS-CoV-2 Vaccination

Living cationic polymerization of isobutylene in seconds based on microflow system

An initiating system composed by ethylaluminum sesquichloride (Et3Al2Cl3)//2,6-dimethylpyridine (DMP) is established for fast living cationic polymerization of isobutylene. The polymerization can be accelerated at utmost to finish in only 4 s with extremely narrow molecular weight distribution in microflow system. Investigations on influence factors reveal that mixing intensity that dependent on Re affects the molecular weight distribution significantly. DMP has two-stage effect, corresponding to its interactions with protonic impurity and Lewis acid respectively. Polymerization rate can be facilely adjusted by changing the volume ratio of mixed solvent of n-hexane and CH2Cl2 from 8:2 to 7:3 with the assurance of livingness. This polymerization system can even operate at elevated temperature as high as −55 °C without the loss of livingness, which is of great beneficial to the commercialization of polyisobutylene-based functional polymer materials.

Formation and structure of iodine complex of polyacrylonitrile studied by vibrational spectroscopy

It has been reported that polyacrylonitrile (PAN) can form a complex with polyiodide ions, which can give some interesting thermal and electronic properties to PAN. However, the formation process and structure characteristics of the PAN-iodine complex interpreted from the molecular level are still unclear. The present research is devoted to clarifying the above problems by studying the PAN film immersed in the iodine aqueous solution with different concentrations and counter cations based on IR and Raman spectroscopy in detail. We have found that the PAN-iodine complex can form through the intermolecular interaction between PAN chains and I 5 − ions by immersing the PAN film into the iodine aqueous solution with an iodine concentration higher than 0.1 mol/L. The ν (CN) and δ (CH 2 ) modes in the IR spectra of PAN showed a remarkable shift through forming the complex in the 1 mol/L iodine solution. Moreover, the PAN-iodine complex formed in the iodine solutions containing the different types of counter ions (K + , Na + , Li + ) may have different structures based on different band positions of ν (CN), δ (CH 2 ), and ν (CH 2 ) mode in their IR spectra. More interestingly, we found that during the formation of the complex, the content of planer zigzag conformation along the atactic PAN chain increased obviously. The present study results may inspire to further develop PAN as a functional polymer material. • The formation process and structure characteristics of the PAN-iodine complex were investigated. • PAN-iodine complex is formed by the intermolecular interactions between PAN chains and I 5 − ions. • Content of the planer zigzag conformation along the PAN chain increases obviously through the complex formation.

Functional polymer materials based on dynamic covalent chemistry

In the past two decades, dynamic covalent chemistry has been greatly developed, which is mainly reflected in two aspects: 1. new dynamic covalent bonds (DCBs) are continuously discovered; 2. various DCBs have been introduced into polymer materials for different functions. These functional polymer materials have brought new opportunities for sustainable development. In this review, we provide an overview of various functions endowed by DCBs in polymer materials, including self-healing, chemical recycling, and shape controlling. Particularly, we pay much attention to the three-dimensional (3D) shape reconfiguration/programming, surface patterning, and reversible actuation. In addition, we also give the current issues, challenges, and opportunities on DCBs-containing materials and point out its developing directions in the future.

Drug Delivery Strategies and Biomedical Significance of Hydrogels: Translational Considerations

Hydrogels are a promising and attractive option as polymeric gel networks, which have immensely fascinated researchers across the globe because of their outstanding characteristics such as elevated swellability, the permeability of oxygen at a high rate, good biocompatibility, easy loading, and drug release. Hydrogels have been extensively used for several purposes in the biomedical sector using versatile polymers of synthetic and natural origin. This review focuses on functional polymeric materials for the fabrication of hydrogels, evaluation of different parameters of biocompatibility and stability, and their application as carriers for drugs delivery, tissue engineering and other therapeutic purposes. The outcome of various studies on the use of hydrogels in different segments and how they have been appropriately altered in numerous ways to attain the desired targeted delivery of therapeutic agents is summarized. Patents and clinical trials conducted on hydrogel-based products, along with scale-up translation, are also mentioned in detail. Finally, the potential of the hydrogel in the biomedical sector is discussed, along with its further possibilities for improvement for the development of sophisticated smart hydrogels with pivotal biomedical functions.

B-N-P-linked covalent organic frameworks for efficient flame retarding and toxic smoke suppression of polyacrylonitrile composite fiber

• B-N-P-linked covalent organic framework (BNPC) is synthesized for the first time. • BNPC significantly flame-retardancy efficiency in polyacrylonitrile fiber. • BNPC provides a kinetic advantage for cyclization-crosslinking of PAN. • The mechanical properties of PAN@BNPC fiber is simultaneously enhanced. Covalent organic frameworks (COFs) recently exhibit great potential as flame-retardant additives for polymers, yet the limited choice of building blocks and skeletons have hampered the improvement of their flame-retardant efficiency. Herein, we develop a novel boron-nitrogen-phosphorus-linked COFs (BNPC) for the first time through a facile self-condensation reaction of hydroxyphenylboronic acid substituted hexachlorocyclotriphosphazene, which is employed as flame-retardant filler for polyacrylonitrile (PAN) fiber. As reflected by cone calorimeter test, by introducing 7 wt% BNPC into PAN fiber, the peak heat release rate (PHRR), total smoke production (TSP) and CO production of PAN@BNPC-7 fiber are significantly decreased by 72.6%, 67.2% and 76.3%, respectively. Simultaneously, the limiting oxygen index (LOI) value is improved from 17.5% to 27.8%. The detailed flame-retardant mechanism analyses demonstrate that the BNPC not only provides a kinetic advantage for initiating the cyclization of PAN chains via an ionic mechanism, which significantly reduces the chain scission/toxic gases (HCN, CO) emission and promote the intermolecular crosslinking of cyclized ladder-like structures, but also offers excellent cooperative catalytic effect to produce highly compact and crosslinked P-B-N-rich char layer barrier on fiber surface. Moreover, the resultant PAN@BNPC-7 composite fiber retains good spinnability and exhibits enhanced mechanical properties. This work offers a scalable strategy for designing COFs with multi-flame retardant elements, endowing its great application potential in functional polymer materials.

Catalyst-Free, Visible-Light-Induced Step-Growth Polymerization by a Photo-RAFT Single-Unit Monomer Insertion Reaction.

Photoinduced polymerization is an attractive technique with the advantages of easy operation, mild conditions, and excellent temporospatial controllability. However, the application of this technique in step-growth polymerization is highly challenging. Here, we present a catalyst-free, visible-light-induced step-growth polymerization method utilizing a photo-RAFT single-unit monomer insertion reaction between the xanthate and vinyl ether groups. Benefitting from this reaction, a pendant cationic RAFT agent can be generated in each repeating unit of the polymer backbone. Both cationic and radical side chain extensions were successfully realized, providing a facile approach for the postpolymerization of step-growth polymers for the development of various functional polymeric materials.

Advance of click chemistry in anion exchange membranes for energy application

AbstractClick chemistry has attracted tremendous attention in polymer synthesis due to its high efficiency, considerable yield, and simple synthesis/work‐up procedures. Among the various functional polymer materials prepared by click chemistry, anion exchange membrane (AEM) is a kind of polyelectrolyte which contains cations attached to the polymer skeleton. Click chemistry not only provides facile pathways for the preparation of AEMs but also generates diverse architectures of AEMs with robust performance. The commonly used click chemistry in AEMs consists of: (i) Diels‐Alder reaction, (ii) thiol‐ene, and (iii) Cu(I)‐catalyzed azide‐alkyne cycloaddition (CuAAC). This review will focus on the advance of click chemistry in the preparation of AEMs, especially synthetic approaches for different AEMs and their corresponding application in energy‐related fields, such as fuel cells, redox flow battery, electrodialysis, and so on.

Functional nanoporous materials from boronate-containing stimuli-responsive diblock copolymers

Functional nanoporous polymeric materials have been prepared from novel polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer precursors containing a reversible boronate ester junction between both blocks.

Functional electrospun polymeric materials for bioelectronic devices: a review

A myriad of polymers is being electrospun into functional bioelectronics. This method has been an effective way not only to fabricate newer devices but also to enhance the performance of the existing bioelecronics.

Recent advances in piezocatalytic polymer nanocomposites for wastewater remediation.

Among several forms of water pollutants, common pesticides, herbicides, organic dyes and heavy metals present serious and persistent threats to human health due to their severe toxicity. Recently, piezocatalysis based removal of pollutants has become a promising field of research to combat such pollutions by virtue of the piezoelectric effect. In reality, piezoelectric materials can produce electron-hole separation upon external vibration, which greatly enhances the production of various reactive oxygen species (ROS) and further increases the pollutant degradation rate. Piezocatalysis does not alter the quality or composition of water, like several other conventional techniques (adsorption and photocatalysis), which makes this technique non-invasive. The simplicity and tremendously high efficacy of piezocatalysis have attracted researchers worldwide and thus various functional materials are employed for piezocatalytic wastewater remediation. In this frontier, we highlight and demonstrate recent developments on polymer based piezocatalytic nanocomposites to treat industrial wastewater in a facile manner that holds strong potential to be translated into a clean and green technology.

Data Platform for the Design of Functional Polymeric Materials

Data Platform for the Design of Functional Polymeric Materials

Multistructural Network Design Enables Polybenzoxazine to Achieve Low-Loss-Grade Super-High-Frequency Dielectric Properties and High Glass Transition Temperatures

An original design strategy for the preparation of thermosetting resins with both super-high-frequency low dielectric constant (k) and low dielectric loss (f) as well as high glass transition temperature (Tg) values is presented. The key to this design strategy is incorporating a bulky group and reactive furan ring to increase the free volume and the cross-linking density, respectively. The formed multistructural networks (relatively dense near furan rings and relatively loose near bulky groups) are beneficial not only for lowering k values but also for maintaining high Tgs of main-chain benzoxazine copolymers. More importantly, the optimized copolymers possess low f values (≤0.008) under 5 and 10 GHz, satisfying the requirement of super-high-frequency communications. The correlations between the free volume and thermal and dielectric properties are also discussed to understand the synergistic mechanism. The work opens a new route for the structural design and preparation of super-high-frequency low dielectric functional polymeric materials.

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review.

Academic research regarding polymeric materials has been of great interest. Likewise, polymer industries are considered as the most familiar petrochemical industries. Despite the valuable and continuous advancements in various polymeric material technologies over the last century, many varieties and advances related to the field of polymer science and engineering still promise a great potential for exciting new applications. Research, development, and industrial support have been the key factors behind the great progress in the field of polymer applications. This work provides insight into the recent energy applications of polymers, including energy storage and production. The study of polymeric materials in the field of enhanced oil recovery and water treatment technologies will be presented and evaluated. In addition, in this review, we wish to emphasize the great importance of various functional polymers as effective adsorbents of organic pollutants from industrial wastewater. Furthermore, recent advances in biomedical applications are reviewed and discussed.

In Situ Generated Crude Trithiocarbonate for Visible Light‐Mediated RAFT Polymerization of Acrylates**

AbstractReversible addition‐fragmentation chain transfer (RAFT) radical polymerization holds great promise in the design and massive production of functional polymeric materials. However, its practical application was restricted by the scale‐up production of chain transfer agents, the insufficient oxygen tolerance, and its environmental impact. In this work, a trithiocarbonate (TTC)‐based RAFT agent ethyl 2‐(((butylthio)carbonothioyl)thio)propanoate was synthesized in situ using shelf‐stable RAFT precursors, i. e., sodium n‐butyl trithiocarbonate (TTCS) and ethyl 2‐bromopropionate (EBrP). The crude product was then directly used in RAFT polymerization of acrylates under the irradiation of LED at 405 nm. First‐order polymerization kinetics was evidenced by proton nuclear magnetic resonance and size exclusion chromatography analysis. The measured molecular weights were close to the theoretical values and the dispersities of poly(tert‐butyl acrylate)s (PtBAs) are as low as 1.08, thanks to the light‐induced activation of the RAFT agent. Well‐defined PtBA is also obtained in the presence of air, due to the intrinsic catalytic behavior of TTC. The proposed method greatly simplifies the set‐up of RAFT polymerization without compromising its control for the polymerization. And it also contributes to reducing the cost and environmental impact of the RAFT polymerization, being promising for the industrialization of RAFT polymerization.

A Versatile Method for the End-Functionalization of Polycarbenes.

End-functionalization is an effective strategy for constructing functional materials. A method for chain-end functionalization of helical polycarbenes is herein developed that relied on Sonogashira coupling reaction. In this work, a family of helical polycarbenes with controlled molecular mass (Mn ) and low polydispersity (Mw /Mn ) is readily prepared using Pd(II) and the Wei-Phos ligand as initiator. The Pd(II) complex is confirmed to remain at the chain end of polycarbene. Subsequently, a series of terminal alkyne derivatives with interesting functional groups, including the F atom, aldehyde, or anthracene groups, are synthesized. They could be installed at the chain end of polycarbene through Sonogashira coupling reaction catalyzed by the Pd(II) complex at the chain end. Moreover, a couple of hybrid block copolymers are easily obtained by installing terminal alkynes modified by another type of polymer. The structures of the isolated polymers are confirmed by 1 H nuclear magnetic resonance (1 H NMR), 19 F nuclear magnetic resonance (19 F NMR), 31 P nuclear magnetic resonance (31 P NMR), and Fourier transform infrared spectroscopy (FT-IR), respectively. The self-assembly properties of the hybrid block copolymers are also investigated by atomic force spectroscopy analysis. By the hereby developed method, various functional groups can be introduced at the chain end of helical polycarbenes for constructing functional polymer materials, moreover, the transition metal residues at the end of polymer chains can be easily removed.

Polyolefins and Polystyrene as Chemical Resources for a Sustainable Future: Challenges, Advances, and Prospects

Nonbiodegradable plastics with inert and saturated C–C backbones comprise the majority of global annual plastics produced, including the ubiquitous polyolefins (polyethylene and polypropylene) and polystyrene. Unlike polymers with cleavable bonds, such as polyesters, polyurethanes, and polycarbonates, these inert plastics are the most challenging to upcycle and cannot be easily broken down by chemical or enzymatic means. Thus, they mostly end up in landfills or are incinerated to produce copious amounts of greenhouse emissions. In recent years, increased research effort has been focused toward the upcycling of low-value plastic waste to give them a new lease of life. However, the unreactive C–C polymer backbones of these plastics have posed formidable challenges for attempts at post-synthetic chemical functionalization and conversion into commodity chemicals. In this Perspective, we discuss these inert plastics as large untapped resources for the production of new functional polymeric materials and valuable industrially relevant feedstock, such as dicarboxylic acids and aromatic compounds. The exciting pioneering work featured herein will hopefully inspire a change in the way we view these waste plastics from a chemical dead-end to versatile raw materials, forming the basis of a more sustainable materials economy.

Advanced Functional Materials for Intelligent Thermoregulation in Personal Protective Equipment.

The exposure to extreme temperatures in workplaces involves physical hazards for workers. A poorly acclimated worker may have lower performance and vigilance and therefore may be more exposed to accidents and injuries. Due to the incompatibility of the existing standards implemented in some workplaces and the lack of thermoregulation in many types of protective equipment that are commonly fabricated using various types of polymeric materials, thermal stress remains one of the most frequent physical hazards in many work sectors. However, many of these problems can be overcome with the use of smart textile technologies that enable intelligent thermoregulation in personal protective equipment. Being based on conductive and functional polymeric materials, smart textiles can detect many external stimuli and react to them. Interconnected sensors and actuators that interact and react to existing risks can provide the wearer with increased safety, protection, and comfort. Thus, the skills of smart protective equipment can contribute to the reduction of errors and the number and severity of accidents in the workplace and thus promote improved performance, efficiency, and productivity. This review provides an overview and opinions of authors on the current state of knowledge on these types of technologies by reviewing and discussing the state of the art of commercially available systems and the advances made in previous research works.

Preparation and application of DNA hydrogels: a review

Deoxyribonucleic acid (DNA) not only serves as the material basis of biological inheritance, but also shows great potential in the development of novel biological materials due to its programmability, functional diversity, biocompatibility and biodegradability. DNA hydrogel is a three-dimensional mesh polymer material mainly formed by DNA. It has become one of the most interesting emerging functional polymer materials in recent years because of the perfect combination of the DNA biological properties that it retained and the mechanical properties of its own skeleton. At present, single- or multi-component DNA hydrogels developed based on various functional nucleic acid sequences or by combining different functional materials have been widely used in the field of biomedicine, molecular detection, and environmental protection. In this paper, the development of preparation methods and classification strategies of DNA hydrogels are summarized, and the applications of DNA hydrogels in drug delivery, biosensing and cell culture are also reviewed. Finally, the future development direction and potential challenges of DNA hydrogels are prospected.

Formulation of silica‐based corn oil transformed polyester acryl amide‐phenol formaldehyde corrosion resistant coating material

AbstractIt is important to check the economic losses due to spontaneous metallic corrosion of major infrastructures, precious equipment's, and ensure the sustainable growth. Fabrication of environmentally benign functional polymeric material by transforming agricultural waste and products into value added polymeric products is of great importance in recent times. Here, we report the formulation of functional hybrid polymeric material using corn oil (CO) as our starting material. The functionality of CO was improved by green route, to produce corn diol fatty amide (HECA). Functionalization of CO was achieved in systematic manner by following green chemistry approach. First, diol fatty amide (HECA) was prepared followed by conversion of terminal OH groups of HECA into acrylic ester using condensation reaction with acrylic acid (AA). The base polymeric moiety was further modified to include phenyl acetylene functionality and SiO2 nanoparticle entities. The formulation of hydrophobic stable polymeric structure is important to sustain highly corrosive environment and long‐lasting performance of the material. The inclusion of different functionality and hydrophobic groups were confirmed by Fourier‐transform infrared and proton nuclear magnetic resonance spectroscopies. The baked coating was finalized by addition of phenol formaldehyde polymeric resin in different phr (part per hundred part of resin). The transmission electron microscopy, scanning electron microscope, energy dispersive X‐ray spectroscopy, and elemental mapping of the coating material confirms the formation of a hybrid material with uniform distribution of inorganic and organic components. The potentiodynamic polarization and electrochemical impedance spectroscopic analysis verified the better resistive performance of inorganic hybrid over the counter organic coatings. The enhanced thermal stability, hydrophobic character, and corrosion resistance performance of CO based coating material indicates the potential of the synthesized green route materials.