Removal of Dye Using Lignin-Based Biochar/Poly(ester amide urethane)Nanocomposites from Contaminated Wastewater

The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility.

Effects of Processing Variables on the Morphology and Diameter of Electrospun Poly(amino acid ester)phosphazene Nanofibers

Poly[（alanino ethyl ester）0.67 （glycino ethyl ester）0.33 phosphazene] （PAGP） was synthesized, and morphology and diameter of the electrospun PAGP nanofibers were systematically evaluated by using a cool field emission scanning electron microscope （SEM） with changing the important processing variables such as applied voltage, polymeric concentration, and ambient temperature. The average diameter of PAGP nanofibers was inversely proportional to the applied voltage, but increased with the increase of solution concentration. Lower environmental temperature was unfavorable due to the nanofibers conglutination.

SYNTHESIS, CHARACTERIZATION OF CHIRAL POLY(ESTER AMIDE)S DERIVED FROM L-ISOLEUCINE

A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl chloride and styrene-2,5- dicarbonyl chloride styrene have been synthesized by interfacial polymerization. The structure of the monomer is elucidated by FT-IR and elemental analysis. The thermal properties of the polymers were studied by DSC and TGA. The chiroptical properties of the above polymer have also been studied by circular dichroism (CD) spectroscopy. Results indicated that these polymers form helical structures.

Facile Route to Aromatic Hyperbranched Poly(ester amines)

The aromatic hyperbranched poly（ester amines）（AHPEAs） were successfully synthesized via the mild condensation of N-4-cyanobenzyl diethanolamine hydrogenchloride as an AB2 monomer in concentrated HCI. The polymerization was monitored by FTIR to suppose the reasonable reaction mechanism. The degree of branching was determined to be 0.55 by 1H NMR with an increased conversion of up to 96%. The glass transition temperature was measured by differential scanning calorimetry to range from -19 to 15℃ The molecular weights and polydispersities were investigated by gel permeation chromatography.

Synthesis and Properties of Thermoplastic Polyisocyanurates:Polyisocyanuratoamide,Polyisocyanurato(Ester-Amide)and Polyisocyanurato(Urea-Ester)

It has been proved that introducing isocyanurate into polymer chains could improve the flame retardancy of polymers.We describe in this work the synthesis and the thermal property study of three thermoplastic polyisocyanurates,which are polyisocyanuratoamide(PICA-6),polyisocyanurato(ester amide)(PICEA-6)and polyisocyanurato(urea ester)(PICUE-6).These polymers show similar and improved thermal stability with the existence of isocyanurate rings.PICA-6 is more crystalizable than the rest two and the melting temperature is found to be around 240℃ but it still crystalizes slowly.For PICEA-6 and PICUE-6,only glass transition can be observed on the DSC traces.The glass transition temperature follows the order of PICA-6>PICEA-6>PICUE-6(101.9,77.9 and 28.7℃,respectively).

In Vitro Antimicrobial Activity Study of Some New Arginine-based Biodegradable Poly （Ester Urethane）s and Poly （Ester Urea）s

Bactericidal activity of some arginine based biodegradable polymers-PEURs （poly （ester urethane）s） and PEUs （poly （ester urea）s） with low cytotoxicity was studied in in vitro experiments. Various bacterial strains both Gram-positive and Gram-negative were used to explore the bactericidal activity of the cationic polymers. As the test objects, the following microorganisms were used： Bacillus subtilis, Staphylococcus aureus, Mycobacterium album, Pseudomonas fluorescens, Escherichia coli, Actinomyces griseus and Aspergillus niger. The obtained results showed that the new cationic polymers suppressed the growth of the studied microorganisms and the bactericidal activity of the tested cationic polymers strongly depending on their chemical structure.

Synthesis and Characterization of Thermoplastic Poly(Ester Amide)s Elastomer (TPEaE) Obtained from Recycled PET

A series of thermoplastic polyester elastomer (TPEE) and thermoplastic poly(ester amide)s elastomer (TPEaE)copolymers were obtained by depolymerizing PET (polyethylene terephthalate) by which the waste PET canbe efficiently recovered and recycled into value-added products from a practical and economical point of view.The structure of TPEE and TPEaE was identified using nuclear magnetic resonance (NMR) and Fourier transforminfrared spectroscopy (FT-IR). Differential scanning calorimetry (DSC) data showed that the melting temperature(Tm) decreased with the amide content increased. The glass transition temperature (Tg) was increased as introducingthe amide group, and the formation of amide-ester and amide-amide hydrogen bonds increased the intermolecularchain force. The intrinsic viscosity (η) showed the tendency of increment from TPEE (0.53 dL g^(−1)) to TPEaE-5%(0.72 dL g^(−1)) due to the reinforcement of hydrogen bond and chain entanglement.

Establishment of a leucine-based poly(ester amide)s library with self-anticancer effect as nano-drug carrier for colorectal cancer treatment

Colorectal cancer is a common cancer worldwide.Traditional chemotherapeutic drugs often face limitations such as poor aqueous solubility and high systemic toxicity,which can lead to adverse side effects and limited therapeutic efficacy.In this study,a library of one kind of biodegradable and biocompatible polymer,leucine based-poly(ester amide)s(Leu-PEAs)was developed and utilized as drug carrier.The structure of Leu-PEAs can be tuned to alter their physicochemical properties,enhancing drug loading capacity and delivery efficiency.Leu-PEAs can self-assemble into nanoparticles by nanoprecipitation and load paclitaxel(PTX)with the diameter of~108 nm and PTX loading capacity of~8.5%.PTX-loaded Leu-PEAs nanoparticles(PTX@Leu-PEAs)demonstrated significant inhibition of CT26 cell growth in vitro.In vivo,these nanoparticles exhibited prolonged tumor accumulation and antitumor effects,with no observed toxicity to normal organs.Furthermore,blank Leu-PEAs nanoparticles also showed antitumor effects in vitro and in vivo,which may be attributed to the activation of the mammalian target of rapamycin(m TOR)pathway by leucine.Consequently,this biocompatible Leu-PEAs nano-drug delivery system shows potential as a promising strategy for colorectal cancer treatment,warranting further investigation.

Synthesis of optically active polymers bearing amino acid moieties by atom transfer radical polymerization

We report here an approach toward the synthesis of optically active polyacrylamide bearing amino acid moieties, poly[Nmethacryloyl L-leucine methyl ester] （PMALM）, with controlled average number molecular weight （Mn） and relatively narrow polydispersity index （PDI, Mw/Mn 〈 1.3） by atom transfer radical polymerization （ATRP） using initiating system methyl 2-bromopropionate/CuBr/tris（2-dimethylaminoethyl） amine. The optical properties of the resulting polymers were evaluated from specific optical rotation value and CD spectra.

Molecular Chain Flexibility and Dielectric Loss at High-Frequency:Impact of Ester Bond Arrangement in Poly(ester imide)s

The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielectric loss.However,the validity of this proposition at high frequencies remains uncertain.To scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic ring.The introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry conditions.The dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)conditions.Furthermore,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic nature.Molecular simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water molecules.Despite sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality films.Our research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.

The Future of Plasticizers: Biobased and Oligomeric

The deficiencies of popular phthalate plasticizers(ready migration from a polymer matrix into which they have been incorporated,flammability,environmental pollution,human health risks)have stimulated efforts to develop new effective,nonmigrating,low-cost,nontoxic replacements.In the main,these have been based on readilyavailable,nontoxic biobased precursors.Some,including those prepared from plant oils,have been generated from biomaterials themselves.However,the more numerous and generally more effective have been generated from discrete compounds produced from various biomaterials.Several structural features of effective plasticizers have been recognized.Polar functionality is required to assure compatibility with a wide range of polymeric materials,including poly(vinyl chloride)(PVC),the most heavily plasticized polymer.A branched structure greatly enhances the effectiveness of compounds used as plasticizers.An oligomeric structure may strongly limit or prevent migration from a polymer matrix.Hyperbranched oligomers of defined structure derived from the readilyavailable,inexpensive,nontoxic biomonomers,glycerol and adipic acid contain all these features and are excellent plasticizers.They contain ester functionality,are highly branched,and display a large number of end groups,all of which contribute to their effectiveness as plasticizers.

Improving gene transfection efficiency of highly branched poly(β-amino ester)s through the in-situ conversion of inactive terminal groups

Highly branched poly(β-amino ester)s(HPAEs)have emerged as a safe and efficient type of non-viral gene delivery vectors.However,the presence of inactive terminal secondary amine groups compromises their gene transfection capability.In this study,HPAEs with similar topological structures and chemical compositions but varying numbers of terminal secondary 4-amino-1-butanol(S4)and secondary/tertiary 3-morpholinopropylamine(MPA)groups were synthesized.The results demonstrate that an increased number of secondary/tertiary MPA groups in-situ significantly enhances the DNA binding capability of HPAEs,leading to the formation of smaller HPAE/DNA polyplexes with higher zeta potential,ultimately resulting in superior gene transfection efficiency in bladder epithelial cells.This study establishes a sim-ple yet effective strategy to maximize the gene transfection potency of HPAEs by converting the inactive terminal groups in-situ without the need for complex modifications to their topological structure and chemical composition.

Improvement in Toughness of Polylactide by Melt Blending with Bio-based Poly(ester)urethane

Polylactide （PLA） was successfully toughened by blending with bio-based poly（ester）urethane （TPU） elastomers which contained bio-based polyester soft segments synthesized from biomass diols and diacids. The miscibility, mechanical properties, phase morphology and toughening mechanism of the blend were investigated. Both DSC and DMTA results manifested that the addition of TPU elastomer not only accelerated the crystallization rate, but also increased the final degree of crystallinity, which proved that TPU has limited miscibility with PLA and has functioned as a plasticizer. All the blend samples showed distinct phase separation phenomenon with sea-island structure under SEM observation and the rubber particle size in the PLA matrix increased with the increased contents of TPU. The mechanical property variation of PLA/TPU blends could be quantitatively explained by Wu＇s model. With the variation of TPU, a brittle-ductile transition has been observed for the TPU/PLA blends. When these blends were under tensile stress conditions, the TPU particles could be debonded from the PLA matrix and the blends showed a high ability to induce large area plastic deformation before break, which was important for the dissipation of the breaking energy. Such mechanism was demonstrated by tensile tests and scanning electron microcopy （SEM） observations.

Synthesis and Characterization of Crystallizable Aliphatic Thermoplastic Poly(ester urethane) Elastomers through a Non-isocyanate Route

A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis（hydroxyethyloxycarbonylamino） hexane （BHCH）, i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly（butylene adipate） prepolymer （PrePBA） with terminal HO-- groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 ℃under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from -33.8 ℃ to -3.1 ℃, Tm from 94.3 ℃ to 111.9 ℃, initial decomposition temperature over 274.7℃, tensile strength up to18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.

Preparation of Poly(ε-caprolactone)/Poly(ester amide)Electrospun Membranes for Vascular Repair

With adjustable amphiphilicity and anionic/cationic charge,biodegradability and biocompatibility,amino acid-based poly(ester amide)s(PEAs)have drawn attention in the research of tissue engineered vascular grafts.In this work,L-phenylalanine-based PEAs with or without L-lysine were synthesized through polycondensation,and ultrafine fibrous grafts consisted of PEAs and poly(ε-caprolactone)(PCL)in given mass ratios were further prepared via blend electrospinning.Surface characterizations by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the chemical structure,and the wettability indicated that the prepared PCL/PEAs electrospun membranes exhibited less hydrophobic than PCL.Tensile results showed that the PCL/PEAs membranes possessed suitable mechanical properties,which could meet the requirements of artificial blood vessels.Cell culture and hemolytic tests exhibited that the PCL/PEAs electrospun membranes are biocompatible.In general,the electrospun grafts of PCL/PEAs could be applied for vascular repair.

Superabsorbent poly(acrylic acid) and antioxidant poly(ester amide) hybrid hydrogel for enhanced wound healing

Wound healing dressing is increasingly needed in clinical owing to the large quantity of skin damage annually.Excessive reactive oxygen species(ROS)produced through internal or external environmental influences can lead to lipid peroxidation,protein denaturation,and even DNA damage,and ultimately have harmful effects on cells.Aiming to sufficiently contact with the wound microenvironment and scavenge ROS,superabsorbent poly(acrylic acid)and antioxidant poly(ester amide)(PAA/PEA)hybrid hydrogel has been developed to enhance wound healing.The physical and chemical properties of hybrid hydrogels were studied by Fourier-transform infrared(FTIR)absorption spectrum,compression,swelling,degradation,etc.Besides,the antioxidant properties of hybrid hydrogels can be investigated through the free radical scavenging experiment,and corresponding antioxidant indicators have been tested at the cellular level.Hybrid hydrogel scaffolds supported the proliferation of human umbilical vein endothelial cells and fibroblasts,as well as accelerated angiogenesis and skin regeneration in wounds.The healing properties of wounds in vivo were further assessed on mouse skin wounds.Results showed that PAA/PEA hybrid hydrogel scaffolds significantly accelerated the wound healing process through enhancing granulation formation and re-epithelialization.In summary,these superabsorbent and antioxidative hybrid hydrogels could be served as an excellent wound dressing for full-thickness wound healing.

Development of L-arginine-based poly(ester urethane)urea for enhanced vascular adaptability

Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for vascular repair still remain challenged.Biodegradable poly(ε-caprolactone)(PCL)has been applied for the preparation of electrospun vascular grafts,but more efforts are needed to improve its compliance with tissue growth.Herein,L-arginine-based poly(ester urethane)urea(PEUU)with both elasticity and biodegradability was synthesized so as to enhance the biomechanical properties of vascular grafts by blending electrospinning with PCL in a given mass ratio.It was exhibited that the prepared electrospun PCL/PEUU fibrous membranes were suitable for cell proliferation with normal cell morphology.More importantly,the electrospun membrane with 1/1 mass ratio of PCL/PEUU(PEUU50)showed specific flexibility,exhibiting more suitable mechanical properties matching to the native blood vessels.Specifically,the PEUU50 electrospun membrane demonstrated significantly lower Young’s modulus(9.3±0.8 MPa)and tensile strength(6.0±0.5 MPa),and extremely higher elongation(389%±24%)in wet state than those(16.3±3.0 MPa,11.4±7.1 MPa and 196%±57%,respectively)of the pristine PCL membrane.Overall,this study demonstrated the great potential of amino acid-based PEUUs for the application in small-diameter vascular grafts.

A Non-isocyanate Route to Poly(ester urethane) with High Molecular Weight: Synthesis and Effect of Chemical Structures of Polyester-diol

A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route,the polyurethane diol was first prepared by the reaction between bis-1,6-hexamethylencarbamate(BHC)and 1,6-hexanediol.A series of polyester soft segments of polyurethane have been synthesized from the polycondensation of adipic acid and different diols,including butanediol,hexanediol,octanediol and decanediol.The subsequent polycondensation of polyurethane diol and polyester diol led to linear PETUs.The resultant polymers were characterized by GPC,FTIR,^(1)H-NMR,^(13)C-NMR,DSC,WAXD,TGA and tensile test.The results indicated that PETUs possess weight-average molecular weights higher than 1×10^(5) and the tensile strength as high as 10 MPa.The thermal properties,crystallization behavior,microphase separation behavior and morphology were studied by DSC and AFM,and the results indicated that the degree of phase separation was affected by two factors,the crystallization and hydrogen bonding interaction between soft segment and hard segment.

pH-Responsive supramolecular micelle based on host-guest interaction of poly(β-amino ester) derivatives and adamantyl-terminated poly(ethylene glycol) for cancer inhibition

Supramolecular structures have received growing attention and been widely applied in many fields.Herein, we synthesized hydrophobic β-cyclodextrin-contained poly(β-amino ester)(PAE-β-CD) and hydrophilic adamantyl-terminated poly(ethylene glycol)(PEG-AD) to form a supramolecular micelle via the host-guest interaction. The micelle displayed pH responsive structure change due to the transform of hydrophobic PAE core to hydrophilic form in weakly acid condition. After the anticancer drug curcumin(Cur) was loaded into the micelle, the drug release behavior of the Cur-loaded micelle was studied, and it turned out that the Cur-loaded supramolecular micelle could effectively unload the drug at pH 5.5.Furthermore, the antitumor efficiency of the Cur-loaded micelle was also examined both in vitro and in vivo, indicating considerable inhibition ratio as high as 62.14% against mouse sarcoma 180.

Aliphatic Segmented Poly（ether ester amide）s Synthesized from Hexanediamine, Sebacic Acid and Poly（ethylene glycol）s

High molecular weight aliphatic segmented poly（ether ester amide）s（PEEAs） were synthesized via melt polycondensation and chain extension. An oligomeric polyamide（PA） terminated mainly with -COOH groups（HOOC-PA-COOH） was prepared from the reaction of nylon 610 salt with sebacic acid. Melt polycondensation of HOOC-PA-COOH with polyethylene glycol（PEG）, such as PEG400, PEG600, PEG1000 and PEG1500, was conducted at 200 ℃, and several segmented PEEA prepolymers（PrePEEAs） were prepared. Chain extension of PrePEEAs was carried out at 190 ℃ using 2,2＇-（1,4-phenylene）-bis（2-oxazoline） and adipoyl biscaprolactamate as combination chain extenders. Chain extended PEEAs（ExtPEEAs） were characterized by gel permeation chromatography（GPC）, Fourier transform infrared spectrophotometer（FTIR）, proton nuclear magnetic resonance（1H NMR）, differential scanning calorimetry（DSC）, wide angle X-ray scattering（WAXS）, thermogravimetry analysis（TGA）, and tensile test. The ExtPEEAs exhibited Mn up to 98700, Tm from 164.2 ℃ to 176.1 ℃, initial decomposition temperature above 320.6 ℃, tensile strength up to 34.80 MPa, and strain at break from 111.92% to 353.12%. Aliphatic segmented PEEAs with good thermal and mechanical properties were prepared.