Preparation Of Polymers Research Articles

Biomass- and Carbon Dioxide-Derived Polyurethane Networks for Thermal Interface Material Applications.

Recent environmental concerns have increased demand for renewable polymers and sustainable green resource usage, such as biomass-derived components and carbon dioxide (CO2). Herein, we present crosslinked polyurethanes (CPUs) fabricated from CO2- and biomass-derived monomers via a facile solvent-free ball milling process. Furan-containing bis(cyclic carbonate)s were synthesized through CO2 fixation and further transformed to tetraols, denoted FCTs, by aminolysis and utilized in CPU synthesis. Highly dispersed polyurethane-based hybrid composites (CPU-Ag) were also manufactured using a similar ball milling process. Due to the malleability of the CPU matrix, enabled by transcarbamoylation (dynamic covalent chemistry), CPU-based composites are expected to present very low interfacial thermal resistance between the heat sink and heat source. The characteristics of the dynamic covalent bond (i.e., urethane exchange reaction) were confirmed by the results of dynamic mechanical thermal analysis and stress relaxation analysis. Importantly, the high thermal conductivity of the CPU-based hybrid material was confirmed using laser flash analysis (up to 51.1 W/m·K). Our mechanochemical approach enables the facile preparation of sustainable polymers and hybrid composites for functional application.

Rapid fabrication of biomimetic PLGA microsphere incorporated with natural porcine dermal aECM for bone regeneration.

Bioactive microspheres coated with acellular extracellular matrix (aECM) have received extensive attention in bone tissue engineering. In this work, biomimetic microspheres with different aECM ratios, uniform size and controllable size were prepared easily by blending natural porcine dermal aECM and poly (lactic-co-glycolic acid) (PLGA) using electrohydrodynamic spraying and solidification actuated by solvent extraction method. In this work, the appropriate polymer concentration and preparation voltage were investigated, and the surface morphology of the microspheres was observed by scanning electron microscope. Sirius red was used to visualize aECM exposure on the surface of the microspheres. The in vitro and in vivo experiments were carried out to evaluate the bioactivity and osteogenic properties of the microspheres. The results showed that the morphology and size of PLGA microspheres had little influence on the aECM blending. In vitro experiments showed that the higher the content of aECM, the better the cell adhesion performance. In vivo, rat calvarial defect models were observed and characterized at 4 and 8 weeks postoperatively, and the values of BV/TV of 50aECM/PLGA were 47.57 ± 1.14% and 72.92 ± 2.19%, respectively. The results showed that the skull healing effect was better in aECM-containing microspheres. In conclusion, aECM/PLGA composite microspheres can increase cell adhesion performance through the addition of aECM. Moreover, in vivo experiments have proved that aECM/PLGA microspheres are beneficial to bone repair, which means the aECM/PLGA microspheres are a promising bone tissue engineering material.

Preparation of Cuprous Iodide Coordination Polymer and Fluorescent Detection of Nitrite: A Comprehensive Chemical Design Experiment

Preparation of Cuprous Iodide Coordination Polymer and Fluorescent Detection of Nitrite: A Comprehensive Chemical Design Experiment

The preparation of an ion-imprinted polymer based on hyperbranched polyamide-amines and epoxy resin and its efficient adsorption mechanism for Cr(VI) from aqueous solutions

The preparation of an ion-imprinted polymer based on hyperbranched polyamide-amines and epoxy resin and its efficient adsorption mechanism for Cr(VI) from aqueous solutions

Preparation of a novel cadmium-containing coordination polymer and catalytic application in the synthesis of N-alkylated aminoquinoline derivatives via the borrowing hydrogen approach.

Herein, we report an efficient and straightforward approach for the synthesis of N-alkylated aminoquinoline derivatives by recyclable Cd-containing coordination polymer-catalyzed reactions of aminoquinolines with primary alcohols via the borrowing hydrogen strategy. In this work, a new type of coordination polymer [Cd(CIA)(phen)2(H2O)]n was successfully designed and fabricated. The molecular structure was corroborated by single-crystal X-ray diffraction and fully characterized by PXRD, FT-IR, TGA, and XPS. Importantly, this polymer revealed high catalytic activity for the N-alkylation reaction of 2-aminoquinoline and 8-aminoquinoline with inexpensive and low-toxicity alcohols as alkylating agents in excellent yields up to 95%. Interestingly, the present synthetic protocol was successfully applied for the gram-level synthesis of several biologically active compounds. In addition, several control reactions were carried out to investigate the possible mechanisms of this transformation. Finally, recycling experiments indicated that the cadmium coordination polymer showed good recovery performance for borrowing hydrogen reactions.

Diversified synthesis of poly(sulfonyl isourea)s by multicomponent polymerizations of isocyanides, sulfonyl azides, and alcohols/phenols

Multicomponent polymerization (MCP) has become a powerful tool for the preparation of polymers with complex or well-defined structures. The development of MCPs that can take full advantage of the great...

Solution processing of crystalline porous material based membranes for CO2 separation.

The carbon emission problem is a significant challenge in today's society, which has led to severe global climate issues. Membrane-based separation technology has gained considerable interest in CO2 separation due to its simplicity, environmental friendliness, and energy efficiency. Crystalline porous materials (CPMs), such as zeolites, metal-organic frameworks, covalent organic frameworks, hydrogen-bonded organic frameworks, and porous organic cages, hold great promise for advanced CO2 separation membranes because of their ordered and customizable pore structures. However, the preparation of defect-free and large-area crystalline porous material (CPM)-based membranes remains challenging, limiting their practical use in CO2 separation. To address this challenge, the solution-processing method, commonly employed in commercial polymer preparation, has been adapted for CPM membranes in recent years. Nanosheets, spheres, molecular cages, and even organic monomers, depending on the CPM type, are dissolved in suitable solvents and processed into continuous membranes for CO2 separation. This feature article provides an overview of the recent advancements in the solution processing of CPM membranes. It summarizes the differences among the solution-processing methods used for forming various CPM membranes, highlighting the key factors for achieving continuous membranes. The article also summarizes and discusses the CO2 separation performance of these membranes. Furthermore, it addresses the current issues and proposes future research directions in this field. Overall, this feature article aims to shed light on the development of solution-processing techniques for CPM membranes, facilitating their practical application in CO2 separation.

Multimechanophore Polymers for Mechanically Triggered Small Molecule Release with Ultrahigh Payload Capacity.

Polymers that release small molecules in response to mechanical force are promising for a variety of applications including drug delivery, catalysis, and sensing. While a number of mechanophores have been developed for the release of covalently bound payloads, existing strategies are either limited in cargo scope or, in the case of more general mechanophore designs, are restricted to the release of one or two cargo molecules per polymer chain. Herein, we introduce a nonscissile mechanophore based on a masked 2-furylcarbinol derivative that enables the preparation of multimechanophore polymers with ultrahigh payload capacity. We demonstrate that polymers prepared via ring-opening metathesis polymerization are capable of releasing hundreds of small-molecule payloads per polymer chain upon ultrasound-induced mechanochemical activation. This nonscissile masked 2-furylcarbinol mechanophore overcomes a major challenge in cargo loading capacity associated with previous 2-furylcarbinol mechanophore designs, enabling applications that benefit from much higher concentrations of delivered cargo.

Multibranched polymethacrylates by anionic grafting-from method via desilylation of poly(4-trimethylsilylmethylstyrene)

Abstract A benzyltrimethylsilane (BnTMS)/potassium tert-butoxide (t-BuOK) initiator system for anionic polymerization was applied to poly(4-trimethylsilylmethylstyrene) (PTMSMS) in the presence of 1,1-diphenylethylene (DPE) to construct polyanion macroinitiators and polymerize methacrylate monomers therefrom. Using this method, desilylation of PTMSMS was quantitatively processed and methacrylate monomers were polymerized from the macroinitiator. The obtained multibranched polymers had narrow molecular weight distributions, indicating the well-controlled polymerization of the monomers from the macroinitiator. Therefore, it was demonstrated that PTMSMS can be a suitable precursor for the preparation of multibranched polymers. Additionally, a sequential addition of methacrylate monomers to the polyanion macroinitiator lead to a core-shell multibranched polymer with a narrow molecular weight distribution.

Engineering the Dielectric Constants of Polymers: From Molecular to Mesoscopic Scales.

Polymers are essential components of modern-day materials and are widely used in various fields. The dielectric constant, a key physical parameter, plays a fundamental role in the light-, electricity-, and magnetism-related applications of polymers, such as dielectric and electrical insulation, battery and photovoltaic fabrication, sensing and electrical contact, and signal transmission and communication. Over the past few decades, numerous efforts have been devoted to engineering the intrinsic dielectric constant of polymers, particularly by tailoring the induced and orientational polarization modes and ferroelectric domain engineering. Investigations into these methods have guided the rational design and on-demand preparation of polymers with desired dielectric constants. This review article exhaustively summarizes the dielectric constant engineering of polymers from molecular to mesoscopic scales, with emphasis on application-driven design and on-demand polymer synthesis rooted in polymer chemistry principles. Additionally, it explores the key polymer applications that can benefit from dielectric constant regulation and outlines the future prospects of this field.

Fabrication of a novel hydrophilic ion-imprinted polymer based on silica-modified magnetic graphene oxide as a sensitive sorbent for the fast separation of silver ions from aqueous media

This paper aimed to evaluate the co-precipitation preparation of a novel magnetic graphene oxide ion-imprinted polymer (IIP) for the recognition and separation of silver ions in aqueous solutions. The synthesis of this adsorbent was established by thermal copolymerization of 4-vinyl pyridine (4-VP) as a functional monomer, salen as a ligand, silver ions as a template ion, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, acetonitrile and chloroform as the solvents, 2,2-azobisisobutyronitrile (AIBN) as an initiator by coating on the surface of magnetic graphene oxide as a magnetic core. The prepared polymer was morphologically characterized by the use of several characterization techniques. A batch-wise adsorption investigation was carried out to determine favorable conditions for proper adsorption, likewise selectivity and reusability. The kinetics of the adsorption process was pseudo-second order and followed the Langmuir isothermal model. The maximum adsorption capacity was 77.6 ± 0.6 mg g−1 at a pH of 4. The involvement of other competing ions revealed that the adsorbent benefits from the selective property of the imprinted cavities.

Synthesis and Characterization of Polyazothiazole and Polyacetyltetrazine from Novel Bis-Ketohydrazonoyl Dichlorides

The present work describes the preparation and characterization of new polyazothiazole and polyacetyltrazine polymers in good yields from new bis-(α-ketohydrazonoyl) dichlorides. Synthesis of the new polyazothiazole proceeds through the reaction of bis-(α-ketohydrazonoyl) dichlorides with 1,4-phenylene[bis(carbothioamide)] in a basic medium to afford novel polyazothiazole derivatives. Additionally, the self-polymerization reaction to synthesize polydiacetyltetrazine derivatives based on bis-(α-ketohydrazonoyl) dichlorides is described. The new polyazothiazole and polyacetyltetrazine derivatives were characterized using spectral and thermal techniques.

One-step preparation of carboxyl-functionalized porous organic polymer as sorbent for enrichment of phenols in bottled water, juice and honey samples

Herein, a novel carboxyl-functionalized porous organic polymer (COOH-POP) was prepared as sorbent. Due to multiple hydrogen bonds and π-π interactions between COOH-POP and phenols, COOH-POP shows good enrichment ability and very fast adsorption rate for phenols. Then, an analytical method was developed for determination of five phenols (2-chlorophenol, bisphenol A, 2,6-dichlorophenol, 2,4-dichlorophenol and p-tert-butylphenol) in bottled water, lemon juice, peach juice and honey samples using COOH-POP as solid phase extraction sorbent in combination with high performance liquid chromatography. Under optimal conditions, the COOH-POP based method gave the detection limits (S/N = 3) of 0.02–0.10 ng mL−1 for bottled water, 0.03–0.12 ng mL−1 for lemon juice, 0.03–0.25 ng mL−1 for peach juice and 0.7–1.5 ng g−1 for honey samples. The recoveries for spiked samples ranged from 84.0 % to 119.0 % with relative standard deviation less than 7.6 %. This study provides a new yet effective method for enrichment of phenols by designing carboxyl-functionalized porous organic polymer as sorbent.

Enhancement of the Photosensitizing Properties of 6-Carboxypterin through Covalent Binding to the pH-Responsive and Biocompatible Poly(allylamine Hydrochloride).

A polymeric photosensitizer was synthesized through covalent attachment of the natural photosensitizer 6-carboxypterin (Cap) to a poly(allylamine hydrochloride) (PAH) polymer. The optimization of the functionalization steps and purification procedure is described. The overall yield of the functionalization reaction was 67% to generate the modified polymer (PAH-Cap), featuring a Cap substitution degree of approximately 1% and advantageous spectroscopic properties. Photosensitizing properties of PAH-Cap were observed to occur via both photooxidation mechanisms, i.e., type I and type II. This feature was demonstrated using a biologically relevant target molecule, 2'-deoxyguanosine (dG). The spectroscopic, photophysical, and photochemical behaviors in aqueous environments were studied and compared to Cap. To explore possible further relevant biological applications, experiments with PAH-Cap and dG were carried out at physiological pH. PAH-Cap can generate singlet molecular oxygen and initiate an electron transfer process at pH 7 in air-saturated solutions upon UVA irradiation. Moreover, based on its spectroscopic features, visible light can be used to initiate the photooxidation of biological compounds in water, with many interesting advantages compared to free Cap and other related pteridines. These advantages include an enhancement of the photosensitizing effect at physiological pH and the potential of PAH-Cap for its use as a building block in supramolecular assemblies. The functionalization strategy hereby described can be employed for the preparation of robust photoactive polymers with great potential for its application in photodynamic therapy (PDT) and disinfection technologies.

Enzymatically Activatable Polymers for Disease Diagnosis and Treatment.

The irregular expression or activity of enzymes in the human body leads to various pathological disorders and can therefore be used as an intrinsic trigger for more precise identification of disease foci and controlled release of diagnostics and therapeutics, leading to improved diagnostic accuracy, sensitivity, and therapeutic efficacy while reducing systemic toxicity. Advanced synthesis strategies enable the preparation of polymers with enzymatically activatable skeletons or side chains, while understanding enzymatically responsive mechanisms promotes rational incorporation of activatable units and predictions of the release profile of diagnostics and therapeutics, ultimately leading to promising applications in disease diagnosis and treatment with superior biocompatibility and efficiency. By overcoming the challenges, new opportunities will emerge to inspire researchers to develop more efficient, safer, and clinically reliable enzymatically activatable polymeric carriers as well as prodrugs.

Preparation and Performance Evaluation of Amphiphilic Polymers for Enhanced Heavy Oil Recovery.

The continuous growth in global energy and chemical raw material demand has drawn significant attention to the development of heavy oil resources. A primary challenge in heavy oil extraction lies in reducing crude oil viscosity. Alkali-surfactant-polymer (ASP) flooding technology has emerged as an effective method for enhancing heavy oil recovery. However, the chromatographic separation of chemical agents presents a formidable obstacle in heavy oil extraction. To address this challenge, we utilized a free radical polymerization method, employing acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, lauryl acrylate, and benzyl acrylate as raw materials. This approach led to the synthesis of a multifunctional amphiphilic polymer known as PAALB, which we applied to the extraction of heavy oil. The structure of PAALB was meticulously characterized using techniques such as infrared spectroscopy and Nuclear Magnetic Resonance Spectroscopy. To assess the effectiveness of PAALB in reducing heavy oil viscosity and enhancing oil recovery, we conducted a series of tests, including contact angle measurements, interfacial tension assessments, self-emulsification experiments, critical association concentration tests, and sand-packed tube flooding experiments. The research findings indicate that PAALB can reduce oil-water displacement, reduce heavy oil viscosity, and improve swept volume upon injection into the formation. A solution of 5000 mg/L PAALB reduced the contact angle of water droplets on the core surface from 106.55° to 34.95°, shifting the core surface from oil-wet to water-wet, thereby enabling oil-water displacement. Moreover, A solution of 10,000 mg/L PAALB reduced the oil-water interfacial tension to 3.32 × 10-4 mN/m, reaching an ultra-low interfacial tension level, thereby inducing spontaneous emulsification of heavy oil within the formation. Under the condition of an oil-water ratio of 7:3, a solution of 10,000 mg/L PAALB can reduce the viscosity of heavy oil from 14,315 mPa·s to 201 mPa·s via the glass bottle inversion method, with a viscosity reduction rate of 98.60%. In sand-packed tube flooding experiments, under the injection volume of 1.5 PV, PAALB increased the recovery rate by 25.63% compared to traditional hydrolyzed polyacrylamide (HPAM) polymer. The insights derived from this research on amphiphilic polymers hold significant reference value for the development and optimization of chemical flooding strategies aimed at enhancing heavy oil recovery.

Exploration on flexible wearable sensor motion monitoring based on novel functional polymer conjugated materials.

With the continuous development of flexible electronics, multi-functional device integration, artificial intelligence technology, etc., flexible wearable sensors are playing an increasingly important role in people's daily motion monitoring. However, current flexible wearable sensors have problems such as low accuracy, poor real-time performance, and poor stability in motion monitoring, which seriously hinder the better application of flexible wearable sensors and are not conducive to the collection and monitoring of motion signals. To this end, this paper designed a flexible wearable sensor motion monitoring system and tested its performance through the preparation and performance research of new functional polymer conjugated materials. The research results show that the motion monitoring system designed based on the new functional polymer conjugated material flexible wearable sensor has good monitoring accuracy and real-time performance. When the output data is 500 pieces, the running monitoring accuracy reaches 95.4%, and the monitoring feedback time is 0.321s; the high jump movement monitoring accuracy rate reaches 97%, and the monitoring feedback time is 0.287s; the long jump movement monitoring accuracy rate reaches 96%, and the monitoring feedback time is 0.296s. This shows that the flexible wearable sensor motion monitoring system of this paper has better performance and can meet the current demand for accuracy and real-time motion monitoring. This study highlights the impact of new functional polymer conjugated materials on flexible wearable sensors, helping to further solve the deficiencies of flexible wearable sensors in sports monitoring and promote their better development.

Low-Fouling and Antibacterial Polymer Brushes via Surface-Initiated Polymerization of a Mixed Zwitterionic and Cationic Monomer.

The use of surface-grafted polymer brushes with combined low-fouling and antibacterial functionality is an attractive strategy to fight biofilm formation. This report describes a new styrene derivative combining a quaternary ammonium group with a sulfobetaine group in one monomer. Surface-initiated polymerization of this monomer on titanium and a polyethylene (PE) base material gave bifunctional polymer brush layers. Grafting was achieved via surface-initiated atom transfer radical polymerization from titanium or heat-induced free-radical polymerization from plasma-activated PE. Both techniques gave charged polymer layers with a thickness of over 750 nm, as confirmed by ToF-SIMS-SPM measurements. The chemical composition of the brush polymers was confirmed by XPS and FT-IR analysis. The surface charge, characterized by the ζ potential, was positive at different pH values, and the number of solvent-accessible excess ammonium groups was found to be ∼1016 N+/cm2. This led to strong antibacterial activity against Gram-positive and Gram-negative bacteria that was superior to a structurally related contact-active polymeric quaternary ammonium brush. In addition to this antibacterial activity, good low-fouling properties of the dual-function polymer brushes against Gram-positive and Gram-negative bacteria were found. This dual functionality is most likely due to the combination of antibacterial quaternary ammonium groups with antifouling sulfobetaines. The combination of both groups in one monomer allows the preparation of bifunctional brush polymers with operationally simple polymerization techniques.

Dynamic Thermostable Cellulosic Triboelectric Materials from Multilevel-Non-Covalent Interactions.

Triboelectric materials present great potential for harvesting huge amounts of dispersed energy, and converting them directly into useful electricity, a process that generates power more sustainably. Triboelectric nanogenerators (TENGs) have emerged as a technology to power electronics and sensors, and it is expected to solve the problem of energy harvesting and self-powered sensing from extreme environments. In this paper, a high-temperature-resistant triboelectric material is designed based on multilevel non-covalent bonding interactions, which achieves an ultra-high surface charge density of 192 µC m-2 at high temperatures. TENGs based on the triboelectric material exhibit more than an order of magnitude higher power output (2750mW m-2 at 200°C) than the existing devices at high temperatures. These remarkable properties are achieved based on enthalpy-driven molecular assembly in highly unbonded states. Thus, the material maintains bond strength and ultra-high surface charge density in entropy-dominated high-temperature environments. This molecular design concept points out a promising direction for the preparation of polymers with excellent triboelectric properties.

Preparation of phenolic hydroxyl-modified hyper-crosslinked polymers and their adsorption performance towards small molecular aromatic amines

Herein, three phenolic hydroxyl-modified hyper-crosslinked polymers were synthesized according to two-step Friedel-Crafts alkylation, and they were applied to adsorb small aromatic amines in aqueous and organic solvents. The first low-temperature Friedel-Crafts at 313 K introduced massive phenolic –OH to the intermediates, then the second high-temperature Friedel-Crafts at 353 K, also known as post-crosslinking reaction, brought a hyper-crosslinked skeleton composed of plentiful rigid methylene bridges to the target products, greatly enhancing the Brunauer-Emmett-Teller (BET) surface area (SBET) and total pore volume (Vtotal) of the polymers. In aqueous solution, the HCPS-BNAP-FDA had great potential for efficient adsorption of aniline and p-nitroaniline (p-NANL), and the Langmuir model predicted that their maximum capacities (qmax) were 209.25 mg/g and 277.30 mg/g, respectively. In cyclohexane solution, the qmax of aniline on HCPS-BNAP-FDA was predicted to be 202.38 mg/g. The removal aniline in aqueous solution could exceed 95 % when the original concentration was less than 200 mg/L, and the final concentration was 0.12 mg/L, much lower than the emission limit of China (GB 4287–2012, China). The polymer with 1,4-bis(chloromethyl)benzene (DCX) as crosslinking agent had the highest SBET (1282 m2/g) and the best adsorption performance for aniline (qmax, 258.73 mg/g). The adsorption mechanism demonstrated that the grafting of phenolic –OH groups improved the adsorption performance, as the possible hydrogen bonds and acid-base interactions. The micropores added via post-crosslinking also achieved a significant increase in adsorption capacity, that is, the pore filling adsorption mechanism.