Commercial Poly Research Articles

Regulation of protonation in aramid nanofiber films for improved mechanical properties

Abstract Aramid nanofibers (ANFs) are a strong and heat resistant nanomaterial that can be isolated from commercial poly(p-phenylene terephthalamide) (PPTA) fibers. These nanofibers allow bottom-up self-assembly to form macroscale structures in various form factors through a simple reprotonation process. However, the mechanical properties of these reassembled ANF structures often fall short of those of PPTA fibers, mainly due to insufficient packing, non-uniform microstructures, and low crystallinity. In this study, we present ANF films with improved mechanical properties prepared by a repeated spin-coating technique combined with a reprotonation process using deionized water and formic acid at concentrations ranging from 20 to 60 wt.%. Extensive analyses were performed on the resulting ANF films to evaluate their surface and cross-sectional morphologies, chemical bonds and compositions, thermal stabilities, and mechanical properties. The fabricated ANF films exhibited remarkable performance, with an elastic modulus of 6.7 GPa, tensile strength of 680 MPa, and toughness of 7.7 MJ m−³, while maintaining the inherent thermal stability of PPTA fibers. These properties significantly exceed those of previously reported ANF films, broadening the potential applications for ANF films in various fields.

Dependence of the crystal structure on the d-units amount in semi-crystalline poly(lactic acid)

The study investigates the impact of the d-lactic acid units content on the crystallinity and crystal structure of commercial poly(lactic acid) (PLA) grades, which are copolymers of poly(l-lactic acid) (PLLA) containing a minor amount of d-units. As the d-units content increases, a detectable decrease in crystallinity was observed along with a simultaneous rise in mobile amorphous fraction (MAF) and a reduction in rigid amorphous fraction (RAF). The percentage of d-units was found not to significantly affect RAF thickness, suggesting that the d-units are not completely excluded from the crystals. The inclusion of d-units as defects in the PLA crystal lattice was confirmed by XRD analysis, which disclosed that the crystal phase gets gradually richer of d-units as the crystallization time evolves. FT-IR analysis proved that the incorporation of d-units in the crystal phase is promoted by the formation of local CH3···O=C interactions, similar to those massively active between PLLA and poly(d-lactic acid) (PDLA) in the stereocomplex. The establishment of these interactions leads to a contraction of the interplanar distances and a decrease in the crystal cell volume with increasing the crystallization time and the d-units percentage. In summary, the study proves that for PLA copolymers containing a d-units percentage at least up to about 8 %, d-units are included in the crystal lattice.

Nitrogen-Rich Covalent Organic Frameworks Composited High-Temperature Proton Exchange Membranes with Ultralow Volume Expansion and Reduced Phosphoric Acid Leakage.

Phosphoric acid (PA) leakage and volume expansion are critical factors limiting long-term stable operation of PA-doped polybenzimidazole (PBI) for high-temperature proton exchange membrane fuel cells. Enhancing the interaction between the polymer matrix and PA provides an effective way to minimize PA loss and inhibit excessive membrane swelling. The covalent organic frameworks (COFs) are helpful in improving the performance of PA-PBI membranes due to the robust frameworks, adjustable structures, and good compatibility with polymers. Here, in this work, we synthesized porous COFs named TTA-DFP containing triazine rings and pyridine groups at room temperature for as short as 2 h without oxygen isolation. TTA-DFP was then blended with commercial poly[2,2'-(p-oxidiphenylene)-5,5'-benzimidazole] (OPBI) to prepare composite membranes. The abundant alkaline N sites in TTA-DFP exhibit strong interactions with PA and OPBI, which not only provide more proton transport pathways to promote proton conduction but also immobilize PA in acidophilic micropores to reduce PA leakage. The composite membranes exhibit a much lower volume swelling ratio than that of the OPBI membrane. The PA retention of the composite membrane after 120 h of treatment at 80 °C and 40% relative humidity can reach as high as 84.6%. Particularly, the proton conductivity of the composite membrane doped with 15 wt% TTA-DFP achieves 0.112 S cm-1 at 180 °C without humidification with a swelling ratio of 24.1%. In addition, it has an optimal peak power density of 824.4 mW cm-2 at 180 °C, which is 1.7 times that of the OPBI membrane. The stability of the composite membrane is much better than that of OPBI at a current density of 0.3 A cm-2 at 140 °C for 120 h.

Acidic polymers reversibly deactivate phages due to pH changes.

Bacteriophages are promising as therapeutics and biotechnological tools, but they also present a problem for routine and commercial bacterial cultures, where contamination must be avoided. Poly(carboxylic acids) have been reported to inhibit phages' ability to infect their bacterial hosts and hence offer an exciting route to discover additives to prevent infection. Their mechanism and limitations have not been explored. Here, we report the role of pH in inactivating phages to determine if the polymers are unique or simply acidic. It is shown that lower pH (=3) triggered by either acidic polymers or similar changes in pH using HCl lead to inhibition. There is no inhibitory activity at higher pHs (in growth media). This was shown across a panel of phages and different molecular weights of commercial and controlled-radical polymerization-derived poly(acrylic acid)s. It is shown that poly(acrylic acid) leads to reversible deactivation of phage, but when the pH is adjusted using HCl alone the phage is irreversibly deactivated. Further experiments using metal binders ruled out ion depletion as the mode of action. These results show that polymeric phage inhibitors may work by unique mechanisms of action and that pH alone cannot explain the observed effects whilst also placing constraints on the practical utility of poly(acrylic acid).

Synthesis and characterization of biobased copolyesters based on pentanediol: (2) Poly(pentylene adipate‐co‐terephthalate)

AbstractTraditionally, most flexible food packaging is made of linear low‐density polyethylene (LLDPE) which cannot easily be recycled, nor will it degrade in a reasonable timescale. In this work, a biobased biodegradable polyester alternative was investigated as a possible replacement for LLDPE. High molecular weight poly (pentylene adipate‐co‐terephthalate) with a 40/60 adipic acid/terephthalic acid mole ratio was synthesized using direct esterification and polycondensation. Glycerol and hexane‐1,2,5,6‐tetrol were added as branching agents to better match the structure of the LLDPE which in turn might help the ability of these materials in film‐blowing. Thermal, mechanical, and rheological properties of the copolyesters were thoroughly investigated. All copolyesters had a weight‐average molecular weight of over 140,000 g/mol, which is necessary for proper rheology, and were thermally stable up to 350°C. The addition of branching agents led to a slight decrease in crystallinity, d‐spacing, melting temperature, enthalpy of melting, stress at break, and elongation at break. However, an increase in Young's modulus and complex viscosity at high frequency were observed compared to PPeAT60 without branching agent added. Although the improved crystallinity and mechanical properties of the copolyesters made them viable for film‐blowing, the slow crystallization rate creates a major challenge.Highlights Linear and branched poly(pentylene adipate‐co‐terephthalate) (PPeAT) synthesized. Properties compared to commercial poly(butylene adipate‐co‐terephthalate) (PBAT). Glass and melting temperatures comparable to commercial PBAT. Extensional and shear viscosity comparable to commercial PBAT. PPeAT stiffness is factor of 2 higher than PBAT; ultimate properties similar.

Mesenchymal Stem Cell and Hematopoietic Stem and Progenitor Cell Co-Culture in a Bone-Marrow-on-a-Chip Device toward the Generation and Maintenance of the Hematopoietic Niche.

Bone marrow has raised a great deal of scientific interest, since it is responsible for the vital process of hematopoiesis and is affiliated with many normal and pathological conditions of the human body. In recent years, organs-on-chips (OoCs) have emerged as the epitome of biomimetic systems, combining the advantages of microfluidic technology with cellular biology to surpass conventional 2D/3D cell culture techniques and animal testing. Bone-marrow-on-a-chip (BMoC) devices are usually focused only on the maintenance of the hematopoietic niche; otherwise, they incorporate at least three types of cells for on-chip generation. We, thereby, introduce a BMoC device that aspires to the purely in vitro generation and maintenance of the hematopoietic niche, using solely mesenchymal stem cells (MSCs) and hematopoietic stem and progenitor cells (HSPCs), and relying on the spontaneous formation of the niche without the inclusion of gels or scaffolds. The fabrication process of this poly(dimethylsiloxane) (PDMS)-based device, based on replica molding, is presented, and two membranes, a perforated, in-house-fabricated PDMS membrane and a commercial poly(ethylene terephthalate) (PET) one, were tested and their performances were compared. The device was submerged in a culture dish filled with medium for passive perfusion via diffusion in order to prevent on-chip bubble accumulation. The passively perfused BMoC device, having incorporated a commercial poly(ethylene terephthalate) (PET) membrane, allows for a sustainable MSC and HSPC co-culture and proliferation for three days, a promising indication for the future creation of a hematopoietic bone marrow organoid.

A Polymer‐Sol Binder Realizes Single‐Particle Binding for Nacre‐Like Piezoelectric Nanocomposites and Component‐Integrated Batteries

AbstractAchieving precisely defined and stable component binding is of great interest for composite materials and batteries, but very challenging owing to the lack of effective strategies to manipulate the binder itself. Here, a concept of single‐particle binding (SPB) strategy is proposed based on a polymer‐sol binder to conquer the above challenge. To do that, a polymer‐sol binder is first prepared by dispersing commercial poly(vinylidene fluoride) (PVDF) powder into a mixture of its solvent and non‐solvent with a rational weight ratio of 8:2. Then, by manipulating this PVDF‐sol microfluid, PVDF particles are uniformly and singly introduced onto the surface of other components, such as graphene oxide nanosheets and battery separators. Results further show that the temperature‐induced sol–gel transition of the microfluid finally generates single‐particle fusion and strong component binding with commercial separators (31.6 N m−1). Meanwhile, a surface‐swelling model is proposed to understand its binding mechanism. Finally, this unique SPB strategy has been employed to fabricate nacre‐like nanocomposites with advanced self‐polarized piezoelectricity (23.0 mV N−1), and component‐integrated batteries with robust separator/electrode interphases. This SPB strategy with the PVDF‐sol binder may inspire significant studies on polymer sol, microfluidics, nanocomposites, battery interfaces and beyond.

Highly permeable carbon nanotube membranes for efficient surface water treatment through separation and adsorption–electrochemical regeneration

Membrane-based processes feature many advantages for surface water treatment over other technologies; however, the trade-off between membrane selectivity and permeability usually results in the failure to obtain high-quality filtrate at a high permeance. In this study, we report a highly permeable sodium alginate/glutaraldehyde cross-linked carbon nanotube (CNT/SA-GA) membrane with high adsorption ability for surface water treatment. The CNT/SA-GA membranes have a well-formed hollow fiber morphology and good conductivity of 166–261 S/m. They could reject >98 % of large-sized molecules (e.g., Alcian Blue 8GX and Congo Red) at high permeances of 137–227 L/(m2·h·bar). Moreover, they could remove ~100 % of smaller molecules (e.g., Rhodamine B (RhB)) through dynamic adsorption with a capacity of ~57.3 mg/g. Benefiting from their good conductivity, the CNT/SA-GA membranes could easily decompose the pollutants after adsorption saturation through electrochemical oxidation and then regenerated themselves. Though the switch between adsorption and electrochemical oxidation (2.0 V), the CNT/SA-GA membranes could remove ~100 % RhB at a high permeance of 342 L/(m2·h·bar), which is one order of magnitude higher than those of nanofiltration membranes. When used for surface water treatment, the CNT/SA-GA membranes exhibited a much higher TOC removal rate than commercial poly(acrylonitrile) (PAN) membranes (56.2 % vs. 7.2 %). LC-MS/MS analysis showed that many small molecules such as caffeine could be effectively removed by the CNT/SA-GA membranes. In addition, they exhibited a higher fouling resistance than PAN membranes, evidenced by their lower permeance decline ratio (10.1 % vs. 43.7 %). This study will promote the development and applications of the CNT-based membranes for water purification.

USP’s characterization of commercial poly(lactic-co-glycolic acid) utilizing SEC-Multi-Angle Light Scattering and Refractive Index techniques via Absolute Method approach

This research focuses on evaluating the data quality and reliability of Size Exclusion Chromatography with Multi-Angle Light Scattering and Refractive Index (SEC-MALS/RI) chromatography in determining molecular weight-related parameters in poly(lactic-co-glycolic) acid (PLGA) polymers. The study utilizes key metrics, particularly percent relative standard deviation (%RSD), to evaluate the precision across different data processing conditions. Exploring baseline selection of the chromatograms reveals that selection of the baseline based on the intrinsic shape of the chromatogram, rather than relying on elution peaks, improves consistency. The study emphasizes the critical role of result fitting in addressing systematic errors and sample heterogeneity, recommending the minima of the elution peak selection range for realistic molecular weight distribution representation. Analysis of light-scattering (LS) detector chromatograms highlights varying effects on different PLGA polymers, emphasizing the need for careful assessment and potential exclusion for precision improvement, especially in the presence of experimental artifacts. Across diverse PLGA polymers, the utilization of different column types, along with considerations such as baseline determination and peak selection, shows minimal variations in Mn, Mw, and polydispersity index (PDI), affirming the consistency of the methodology. The %RSD analysis further supports the methodology's precision, with values well within acceptable limits. In summary, this comprehensive evaluation of methodological conditions, including baseline selection, result fitting, LS detector data management, and column types, establishes a reliable SEC-MALS/RI chromatographic approach by Absolute Method for determining molecular weight parameters in PLGA polymers.

Modification of the polymer PETG by 16 MeV Au ions

Commercial poly(ethylene glycol-co-1,4 cyclohexanedimethanol terephthalate) (PETG) foils were irradiated with 16 MeV Au7+ ions and the resulting modifications in the polymer chemical structure, optical properties, and surface hydrophobicity were analyzed. Under irradiation, PETG displays a redshift in the optical absorbance edge, accompanied by a decrease in the optical gap from 3.8 eV to 2.4 eV. An overall decrease of characteristic functional groups is observed with damage cross sections varying from (1–2) × 10-13 cm2. New bands are formed linked mainly to oxidation and formation of conjugated carbon–carbon double bonds. The hydrophilicity of the irradiated surfaces increases possibly due to surface oxidation.

Poly(butylene oxalate-co-terephthalate): A PBAT-like but rapid hydrolytic degradation plastic

Concerns over worldwide plastic pollution have led to the development of biodegradable polyester materials with excellent physical and chemical properties through the copolymerization of poly(butylene oxalate) (PBOx). As a result, poly(butylene oxalate-co-terephthalate)s (PBOTs) with varying compositions, were prepared by incorporating aromatic units. Studies have indicated that PBOT-47 (with a 47% molar terephthalate), exhibits exceptional mechanical properties. With an elongation at break of 1160% and a tensile strength that remains above 30 MPa, similar to or even better than those of the commercial biodegradable plastic poly(butylene adipate-co-terephthalate) PBAT-47 (47% molar terephthalate). Moreover, the permeability coefficients of PBAT-47 for H2O, CO2 and O2 were 5.8, 50.6 and 5.6 times higher than that of PBOT-47, revealing the superior barrier properties of PBOT. Through experimental research and theoretical simulation, the mechanism of the copolymer hydrolysis was elucidated. The readily hydrolytic nature of the oxalate unit endows it with the capacity for rapid degradation, possessing the potential to be a short-term degradable material with physical properties similar to PBAT.

Green-solvent processable polymeric hole transport materials with functional groups for inverted perovskite solar cell

Exploring novel hole transport materials (HTMs) with high hole mobility and eco-friendly processability are imperative for the commercialization of perovskite solar cells (PSCs). However, there is a ‘trade-off’ that the introduction of large-conjugated units aiming to ensure high hole mobility, inevitably compromises the green-solvent solubility of HTMs. In this work, a hybrid strategy of rigidity and flexibility is proposed, in which the conjugated unit is assembled by the rigid binaphthylamine core, and the amide-bond constitutes the flexible backbone. Polar solubilizing units ethylenedioxythiophene and thiophene are used as bridges to construct two kinds of polymers, cited as EDOT-SMe and T-SMe, respectively. Both polymers achieve high hole mobility, well-matched energy levels and efficient defect passivation effect toward the perovskite films. When processing the HTM films with the green solvent (2-methylanisole), the corresponding PSCs deliver fill factors as high as 82.7% for EDOT-SMe and 81.9% for T-SMe, respectively. Consequently, power conversion efficiencies of 20.25% for EDOT-SMe and 20.09% for T-SMe are realized, outperforming that of commercial polymer poly[bis(4-phenyl) (2,4,6-trimethylphenyl)amine] (PTAA, 19.71%). Moreover, PSCs with these polyamides achieve good long-term stability. This work paves a new path for exploring efficient and green-solvent processable polymeric HTMs.

Poly(Imide) Separator Functionalized by Melamine Phosphonic Acid for Regulating Structural and Thermal Stabilities of Lithium-ion Batteries

As the energy density of lithium-ion batteries (LIBs) continues to increase, various separators are being developed to with the aim of improving the safety performance. Although poly(imide) (PI)-based separators are widely used, it is difficult to control their pore size and distribution, and this may further increase the risk associated. Herein, a melamine phosphonic acid (MP)-coated PI separator that can effectively control the pore structure of the substrate is suggested as a remedy. After the MP material is embedded into the PI separator with a simple one-step casting process, it effectively clogs the large pores of the PI separator, preventing the occurrence of internal short circuits during charging. It is anticipated that the MP material can also suppress rapid thermal runaway upon cycling due to its ability to reduce the internal temperature of the LIB cell caused by the desirable endothermic behavior around 300°C. According to experiments, the MP-coated PI separator not only decreases the thermal shrinkage rate better than commercial poly(ethylene) (PE) separators but also exhibits a desirable Gurley number (109.6 s/100 cc) and electrolyte uptake rate (240%), which is unique. The proposed separator is electrochemically stable in the range 0.0–5.0 V (vs. Li/Li+), which is the typical working potential of conventional electrode materials. In practice, the MP-coated PI separator exhibits stable cycling performance in a graphite–LiNi0.83Co0.10Mn0.07O2 full cell without an internal short circuit (retention: 90.3%).

Small Channels Assembled by Multilayer ZIF-8 in Nanocomposite Membranes for Filtration of Ofloxacin in Water.

Metal-organic framework (MOF)-based hybrid membranes still face many unsolved difficulties in the field of liquid separation, with a reliable production technique standing out, in particular, for the water-stable MOF membranes. In this study, zeolitic imidazolate framework-8 (ZIF-8) with acceptable water stability, favorable polymer affinity, and high selectivity was meticulously grafted on commercial poly(vinylidene fluoride) (PVDF) via substrate carboxylation-assisted etching and then overlaid onto PVDF to fabricate a novel hybrid membrane by a layer-by-layer self-assembly method. The optimal membrane manufacturing conditions, including assembly time (10 min), Hmim/Zn2+ molar ratio (8:1), and optimal layer number (three layers), were thoroughly investigated for cutting-off ofloxacin in water filtration. Under low pressure, a nanofiltration scale permeability of about 199.2 L m-2 h-1 MPa-1 and 97.9% rejection of ofloxacin were obtained in bench-scale tests based on the synergistic effect of the Donnan effect and steric hindrance. More significantly, the resulting hybrid membrane demonstrated excellent hydrophilicity, high antifouling, and mechanical and repeatability performances, suggesting promising application possibilities in real-world wastewater filtering settings.

Rapid separation of MOFs particles with the aid of PVDF hollow fiber membrane

Metal-organic frameworks (MOFs) have been widely investigated due to their fascinating structures and properties. However, the time-cost synthetic process and the difficult separation from liquid phase hinder their practical application. In this study, a self-made automatic apparatus containing commercial poly(vinylidene fluoride) (PVDF) hollow fiber membranes was used to separate MOFs from large-volume suspension. Taking MIL-88A(Fe) synthesized with industrial-grade chemicals as an example, the investment cost, operation cost, human cost, time duration during separation process, and unit cost price of MIL-88A(Fe) were significantly reduced by 62%, 82%, 100%, 90%, and 36%, respectively, compared to those of centrifugation. More importantly, MIL-88A(Fe) powders that were separated and purified by the apparatus were easy to be removed from membrane surface by slight vibration, which displayed good morphology, crystallinity, as well as high degradation efficiency toward organic contaminants via photo-Fenton reaction. Meanwhile, the membrane can be reused instantly without any rinse. More encouragingly, this method is applicable to other MOFs’ separation, like ZIF-8 and ZIF-67. This study further confirmed the potential and prospective of high-throughput production and facile separation of MOFs for practical applications.

Hybrid Binder Chemistry with Hydrogen-Bond Helix for High-Voltage Cathode of Sodium-Ion Batteries.

Since sodium-ion batteries (SIBs) have become increasingly commercialized in recent years, Na3V2(PO4)2O2F (NVPOF) offers promising economic potential as a cathode for SIBs because of its high operating voltage and energy density. According to reports, NVPOF performs poorly in normal commercial poly(vinylidene fluoride) (PVDF) binder systems and performs best in combination with aqueous binder. Although in line with the concept of green and sustainable development for future electrode preparation, aqueous binders are challenging to achieve high active material loadings at the electrode level, and their relatively high surface tension tends to cause the active material on the electrode sheet to crack or even peel off from the collector. Herein, a cross-linkable and easily commercial hybrid binder constructed by intermolecular hydrogen bonding (named HPP) has been developed and utilized in an NVPOF system, which enables the generation of a stable cathode electrolyte interphase on the surface of active materials. According to theoretical simulations, the HPP binder enhances electronic/ionic conductivity, which greatly lowers the energy barrier for Na+ migration. Additionally, the strong hydrogen-bond interactions between the HPP binder and NVPOF effectively prevent electrolyte corrosion and transition-metal dissolution, lessen the lattice volume effect, and ensure structural stability during cycling. The HPP-based NVPOF offers considerably improved rate capability and cycling performance, benefiting from these benefits. This comprehensive binder can be extended to the development of next-generation energy storage technologies with superior performance.

Multifunctional polymeric guanidine and hydantoin halamines with broad biocidal activity

Prolonged and excessive use of biocides during the coronavirus disease era calls for incorporating new antiviral polymers that enhance the surface design and functionality for existing and potential future pandemics. Herein, we investigated previously unexplored polyamines with nucleophilic biguanide, guanidine, and hydantoin groups that all can be halogenated leading to high contents of oxidizing halogen that enables enhancement of the biocidal activity. Primary amino groups can be used to attach poly(N-vinylguanidine) (PVG) and poly(allylamine-co-4-aminopyridine-co-5-(4-hydroxybenzylidene)hydantoin) (PAH) as well as a broad-spectrum commercial biocide poly(hexamethylene biguanide) (PHMB) onto a solid support. Halogenation of polymer suspensions was conducted through in situ generation of excess hypobromous acid (HBrO) from bromine and sodium hydroxide or by sodium hypochlorite in aqueous solutions, resulting in N-halamines with high contents of active > N-Br or > N-Cl groups. The virucidal activity of the polymers against human respiratory coronavirus HCoV-229E increased dramatically with their halogenation. Brominated PHMB-Br showed activation activity value > 5 even at 1 mg/L, and complete virus inhibition was observed with either PHMB-Br or PAH-Br at 10 mg/mL. Brominated PVG-Br and PAH-Br possessed fungicidal activity against C. albicans, while PHMB was fungistatic. PHMB, PHMB-Br and PAH polymers demonstrated excellent bactericidal activity against the methicillin-resistant S. aureus and vancomycin-resistant E. faecium. Brominated polymers (PHMB-Br, PVG-Br, PAH-Br) were not toxic to the HeLa monolayers, indicating acceptable biocompatibility to cultured human cells. With these features, the N-halamine polymers of the present study are a worthwhile addition to the arsenal of biocides and are promising candidates for development of non-leaching coatings.

A novel barrier membrane with long-term ROS scavenging function for complete prevention of postoperative adhesion

Local oxidative stress induced by surgical trauma has been recognized as one of pathogenesis for postsurgical adhesion tissue formation. Herein, tannic acid (TA) based metal-phenolic networks (MPNs) was assembled via chelating with Fe3+, and acted as a novel bio-filler for nanofibrous polycaprolactone (PCL) barrier membrane to endow it with reactive oxygen species (ROS) scavenging capacity. By chelating with Fe3+, the release of TA could last for more than 20 days, rendering the membrane with continuous ROS scavenging capacity. The modified membrane could effectively inhibit fibroblasts adhesion and proliferation, as well as immune cells recruitment, infiltration, and expression of pro-inflammatory cytokines. Consequently, a complete prevention of peritoneal adhesion formation was obtained in a rat model of sidewall defect-cecum abrasion, far better than commercial Poly lactic acid (PLA) membrane. Systematic biological mechanism investigations revealed that the enhanced anti-adhesion function was mainly ascribed to its robust ROS scavenging capacity, through which the PI3K-Akt signaling pathway was blocked, leading to repress of downstream NF-κB-TGFβ1-SMAD signaling pathway, finally inhibiting the bioactivity of fibroblasts and immune cells. This work provided a new strategy for the design of advanced barrier membrane, demonstrated its efficacy and mechanism on preventing postoperative adhesion, holding great promise for future clinical application.

Eudragit® L100 Post-Modification via Ugi Multicomponent Reaction

This work investigated the post-modification of commercial poly(methyl mechacrylate-coacrylic acid) using the versatile multicomponent Ugi reaction. This reaction introduces diverse functionalities to tailor the polymer properties effectively. The commercial copolymer which is known for biocompatibility and drug delivery application was subjected to the Ugi reaction, altering its chemical structure. The structure of the modified polymer was checked by Fourier transform infrared spectroscopic and nuclear magnetic resonance and thermal characterizations, confirming successful Ugi component integration. Additionally, gel permeation chromatography assessed molecular weight changes. Results revealed enhanced thermal stability of the modified polymers compared to unmodified polymer, potentially advantageous in high-temperature applications. In summary, the study demonstrates efficient poly(methyl mechacrylate-co-acrylic acid) post-modification through a multicomponent Ugi reaction, yielding tailored polymers. Comprehensive spectroscopic, thermal, and gel permeation analyses shed light on structural changes and improved stability, pivotal for innovative applications like drug delivery.

Thiol-ene click chemistry incorporates carboxylic acid-terminated alkane pendants on polycyclooctene to tune properties

Dehydrogenation and subsequent chemical modification of polyolefins emerges as a promising polymer-to-polymer upcycling pathway. We report the functionalization of polycyclooctene (PCOE), a model for dehydrogenated polyethylene, by thiol-ene click chemistry to install carboxylic acid (COOH) terminated alkane pendant groups. This functionalization approach attached three pendants of different alkane spacer length: thioglycolic acid, mercaptopropionic acid, and mercaptooctanoic acid. Functionalization attached pendants to 3–22 mol% of the ethylene monomeric units, was well controlled by varying reaction stoichiometry and time, and did not require acid groups protections. Greater than 95% of the COOH groups participated in secondary bonding, forming aggregates detectable in X-ray scattering at high COOH mass fractions. Crystallinity and melting temperature decreased with increasing COOH mass fraction. Dynamic mechanical analysis (DMA) reveals both COOH mass fraction and pendant architecture tunes the rubbery plateau moduli, which is well described by the molar mass per backbone bond. This functionalized polymer exhibits commensurate surface and mechanical properties to commercial poly(ethylene-co-acrylic acid).