Physicochemical Properties Of Poly Research Articles

Synthesis and Physicochemical Properties of Poly(2‐Alkyl‐2‐Oxazoline)‐Conjugated Hemoglobins as an Artificial O2 Carrier: Comparison with Polyethylene Glycol Conjugates

AbstractPolyethylene glycol (PEG) is a biocompatible polymer extensively employed to prolong blood circulation and mitigate the immunogenicity of the protein therapeutics. Nonetheless, there are reports of anti‐PEG antibody production. Poly(2‐alkyl‐2‐oxazoline) (PROx) exhibits analogous immunological stealth properties and represents a potential substitute for PEG. This study details the synthesis of PROx‐conjugated hemoglobins (PROxm‐Hbs, R = Me, Et) as artificial O2 carriers, functioning as red blood cell (RBC) substitutes, and evaluates their O2 affinities and solution properties. The average number of polymers bound is designed to be 6 or 11. The O2 affinities (P50) of PMeOxm‐Hbs and PEtOxm‐Hbs are ascertained as 9 Torr, comparable to those of PEG‐conjugated Hbs (PEGm‐Hbs). The PEtOx6‐HbT, synthesized under an N2 atmosphere, exhibited a low O2 affinity (P50 = 57 Torr). Through the admixture of PEtOx6‐Hb and PEtOx6‐HbT, the P50 value of the formulation to range from 9 to 57 Tor can be tailored as desired. The colloid osmotic pressures and viscosities of PMeOxm‐Hb and PEtOxm‐Hb solutions are lower than those of the corresponding PEGm‐Hb solutions. Furthermore, the PROx conjugates evinced no cytotoxicity against normal cells. PMeOxm‐Hbs and PEtOxm‐Hbs, characterized by their appropriate O2 affinities and solution properties, present themselves as promising alternative materials to RBCs.

PH-sensitive and redox-responsive poly(tetraethylene glycol) nanoparticle-based platform for cancer treatment

Effective drug delivery with precise tumour targeting is crucial for cancer treatment. To address the challenges posed by the specificity and complexity of the tumour microenvironment, we developed a poly(tetraethylene glycol)-based disulfide nanoparticle (NP) platform and explored its potential in cancer treatment, focusing on drug loading and controlled release performance. Poly(tetraethylene glycol) NPs were characterised using nuclear magnetic resonance spectroscopy, mass spectrometry, and ultraviolet-visible spectroscopy. Additionally, we evaluated physicochemical properties, including dynamic light scattering, zeta potential analysis, drug loading capacity (DLC), and drug loading efficiency (DLE). The impact of NPs on the mouse colorectal cancer cell line (CT26) and NIH3T3 cells was assessed using a cytotoxicity assay, live/dead staining assay, flow cytometry, and confocal fluorescence microscopy. The experimental results align with the expected chemical structure and physicochemical properties of poly(tetraethylene glycol) NPs. These NPs exhibit high DLE (78.7%) and DLC (12%), with minimal changes in particle size over time in different media.In vitroexperiments revealed that the NPs can induce significant cytotoxicity and apoptosis in CT26 cells. Cellular uptake notably increases with increasing concentration and exposure time. The confocal microscopic analysis confirmed the effective distribution and accumulation of NPs within cells. In conclusion, poly(tetraethylene glycol) NPs hold promise for improving drug-delivery efficiency, offering potential advancements in cancer treatment.

Branching in poly(amine-co-ester) polyplexes impacts mRNA transfection

Branching is a key structural parameter of polymers, which can have profound impacts on physicochemical properties. It has been demonstrated that branching is a modulating factor for mRNA delivery and transfection using delivery vehicles built from cationic polymers, but the influence of polymer branching on mRNA delivery remains relatively underexplored compared to other polymer features such as monomer composition, hydrophobicity, pKa, or the type of terminal group. In this study, we examined the impact of branching on the physicochemical properties of poly(amine-co-esters) (PACE) and their efficiency in mRNA transfection in vivo and in vitro under various conditions. PACE polymers were synthesized with various degrees of branching ranging from 0 to 0.66, and their transfection efficiency was systemically evaluated. We observed that branching improves the stability of polyplexes but reduces the pH buffering capacity. Therefore, the degree of branching (DB) must be optimized in a delivery route specific manner due to differences in challenges faced by polyplexes in different physiological compartments. Through a systematic analysis of physicochemical properties and mRNA transfection in vivo and in vitro, this study highlights the influence of polymer branching on nucleic acid delivery.

Nitrogen ion beam radiation induced modification on physico-chemical properties of poly (vinyl chloride)/ethylene vinyl acetate blends

Nitrogen ion beam radiation induced modification on physico-chemical properties of poly (vinyl chloride)/ethylene vinyl acetate blends

Modulating Polymerization Behaviors of Ether–Ester Monomers and Physicochemical Properties of Poly(ether-alt-ester)s by Heteroatom Substitutions

Modulating Polymerization Behaviors of Ether–Ester Monomers and Physicochemical Properties of Poly(ether-<i>alt</i>-ester)s by Heteroatom Substitutions

Investigation on the physicochemical properties of poly (ethylene-co-vinyl acetate)/mesoporous silica nanocomposites: Effects of content and surface functionalization

In this study, poly (ethylene-co-vinyl acetate)/mesoporous silica EVA/SBA-15 nanocomposites, containing 0.5, 1.5, and 2.5 wt% of unfunctionalized and functionalized SBA-15 were prepared by melt blending in an internal mixer. Mesoporous silica was synthesized through the sol-gel method and modified by hexadecyltrimethoxysilane (HDTMS). Several characterizations were performed; including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), mechanical properties, dynamic mechanical analysis (DMA), and dielectric study to characterize the physicochemical properties of elaborated materials. The results revealed the successful synthesis and functionalization of mesoporous silica, as confirmed by the FTIR and SEM. The crystallinity of the nanocomposites decreased and the elastic modulus increased with the incorporation of the mesoporous silica. Measurement of tensile properties shows that the tensile strength of the nanocomposite content of 1.5 wt% F-SBA-15 is 17.2% is higher as compared to pure EVA. DMA analysis validates the improvement in mechanical properties of the EVA/SBA-15 samples. SEM images displayed well-dispersed F-SBA-15 nanoparticles and enhanced interfacial adhesion between the phases. TGA indicates the enhancement of the thermal stability of nanocomposites as compared with the pure EVA matrix. The surface functionalization presented an approach to preparing nanocomposites with enhanced thermal stability and a low dielectric constant.

Study of Cryostructuring of Polymer System. 65. Features of Changes in the Physicochemical Properties of Poly(vinyl alcohol) Cryogels Caused by the Action of Aqueous Solutions of Amino Acids of General Formula H2N–(CH2)n–COOH

Study of Cryostructuring of Polymer System. 65. Features of Changes in the Physicochemical Properties of Poly(vinyl alcohol) Cryogels Caused by the Action of Aqueous Solutions of Amino Acids of General Formula H2N–(CH2)n–COOH

PREPARATION AND EVALUATION OF PROPRANOLOL HCL AND CARBAMAZEPINE RELEASE PROFILES FROM POLY(Є-CAPROLACTONE) MICROPARTICLE BLENDS SYSTEM

Objective: The goal of this research was to look into the physicochemical properties of poly(-caprolactone) microparticle blends that contained medicines of various solubilities (Propranolol HCl [Pro] and carbamazepine [CBZ]). Methods: W/O/W emulsion for Pro and O/W emulsion for CBZ were used to create microparticle blends. With dispersion time intervals (DTI) of 0 and 60 min, the Pro emulsion (W/O) and CBZ oil phase (O) were dispersed in an external aqueous phase (W). Scanning electron microscopy was used to examine the morphology of microparticle blends (SEM). Focused beam reflectance measurements were utilized to monitor the particle size mean of emulsion droplets/hardened microparticles (FBRM). In phosphate buffer (pH 7.4), encapsulation efficiency (EE) and in vitro drug release were also examined. Results: The final microparticle blends generated by solvent evaporation method were spherical and had two populations, according to the findings. The size of microparticle blends prepared with DTI 60 min and stirring duration 4 h was bigger than those prepared with DTI 0 min, according to FBRM data. In microparticle blends, encapsulation efficiency ranged from 62.05±3.74 percent to 66.38±4.16 percent for Pro and 70.56±4.62 percent to 73.85±4.11 percent for CBZ. After 28 d, drug release in phosphate buffer revealed that Pro release (33%) was shorter than CBZ release (60%) from microparticle blends with DTI 60 min. This was related to the interaction of the oil phase (CBZ) with hard particles from the primary emulsion (Pro), in which the oil phase occluded and covered surface structure of the harsh particles from the primary emulsion. Conclusion: Novel microparticle blends comprising drugs/medicines with varying solubilities (e. g. propranolol HCl and carbamazepine) have a lot of promise as controlled-release drug delivery systems. The physical properties of microparticle blends were impacted by the type of dispersion time interval used.

Physicochemical properties of poly (vinylidene fluoride) membrane grafted poly hydroxyethyl acrylates using radiation-induced graft admicellar polymerization

Admicellar polymerization of hydroxyethyl acrylate onto PVDF membranes was investigated using electron beam irradiation to initiate the grafting in order to modify its inheritant physical and chemical properties. The absorbed dose and the monomer concentration controlled the amount of poly hydroxyethyl acrylate (polyHEA) grafted. The grafting degree increased from 8.35 wt% to 27.6 wt% for monomer concentration of 0.5 M and from 21.8 wt% to 48.1 wt% for monomer concentration of 1.0 M, at absorbed dose of 10–50 kGy. The TGA thermogram showed an increase in the DTG degradation peak that occurs within the range 468.35 °C–481.71 °C as the degree of grafting due to the polyHEA on the PVDF surface. Meanwhile, the surface roughness decreased from 94.97 nm for unmodified PVDF to range of 32.86 nm–65.45 nm for the grafted membrane due to the microstructure of polyHEA grafted on the membrane filled the hill and valley in the PVDF membrane. Furthermore, the PVDF membranes with polyHEA demonstrated a lower water contact angle value (45.9°–60.6°) than the unmodified PVDF membranes (75.8°). Hence, radiation-induced admicellar polymerization is a technique that can be utilised as one of the approaches to modify the surface of any membrane.

Water model determines thermosensitive and physicochemical properties of poly(N-isopropylacrylamide) in molecular simulations

Poly (N-isopropylacrylamide) (PNIPAM) is a famous representative of thermosensitive polymers. Thermosensitive polymers undergo a phase transition with lower critical solution temperature. Commonly, their phase behavior is linked to a conformational collapse above a certain temperature. This thermosensitive conformational transition is called Coil-Globule transition. In contrast, most other polymers usually show inverse temperature behavior, i.e., an upper critical solution temperature, corresponding to a Globule-Coil transition. Besides their numerous possible applications, thermosensitive polymers are of interest for fundamental research, because of similarities to macromolecular conformational transitions, e.g., protein folding. The counter-intuitive behavior of thermosensitive polymers is commonly associated with solvation effects. Thus, an accurate description of the solvent is crucial for the investigation of thermosensitive polymers in molecular simulations. Here, we investigate the influence of the in silico water model on the thermosensitive Coil-Globule transition in molecular dynamics simulations. To this end, we performed extensive atomistic simulations of the syndiotactic PNIPAM 20-mer at multiple temperatures with eight different water models–four of which are 3-point water models (TIP3P-type) and four are 4-point water models (TIP4P-type). We found that the thermosensitive Coil-Globule transition is strongly influenced by the water model in the simulations. Depending on the water model, the conformational ensemble of the polymer is shifted significantly, which leads to dramatically different results: The estimated transition temperature may span between 255 and 350 K. Consequently, depending on the description of the solvent, the physicochemical and mechanical properties of these polymers, e.g., the polymer-solvent affinity and persistence length, vary. These divergent results originate from the strength of interactions between polymer and solvent, but also on the bulk state of the solvent. Both these quantities vary between water models. We found that the Lennard-Jones interaction parameter ϵ of the water model correlates with the transition temperature of the polymer. Indeed, the quadrupole moment of the water model shows an even higher correlation with this quantity. Our results suggest a connection between the phase diagram of the solvent and the thermosensitive transition of the polymer.

Gamma radiation shielding performance and physico-chemical properties of poly (vinyl alcohol)/Cd(NO3)2 composite films

Abstract To improve a radiation shielding performance of the polymer composite, poly (vinyl alcohol) (PVA) was composited with cadmium nitrate. Its radiation shielding capabilities of PVA/Cd(NO3)2 composite films were investigated at three different Cd(NO3)2 concentration levels: 5, 10, and 15% wt. The structural, thermal, and optical properties of the synthesized composite films were examined. The addition of cadmium nitrate to the polymer worsened its thermal stability and improved its optical energy band gap by lowering its direct bandgap energy from 4.56 to 3.25 eV for PVA and PVA/15 wt% Cd(NO3)2 films, respectively. The gamma-ray shielding capacity of the composite was examined using radioactive sources including 241Am (59.5 keV),57Co (122 keV), 192Ir (346 keV) and 137Cs (662 keV). The Micro-Shielding program was used to compare the experimental results of gamma transmittance with theoretical calculations, and the results were found to be in good agreement. Radiation shielding performance of PVA/Cd(NO3)2 composite films was examined by the determination of the linear attenuation coefficient (µ), mass attenuation coefficient (µ m), half value layer (HVL) and exposure buildup factor (EBF). The reinforcement of PVA matrix with 15 wt% Cd(NO3)2 supported to increase the radiation shielding capacity by 13.7% for gamma photons of 57Co radioisotope.

Cryostructuring of Polymeric Systems. 61. Physicochemical Properties of Poly(vinyl alcohol) Cryogels Prepared on the Basis of Urea-Containing DMSO-Solutions of the Polymer and Evaluation of the Resultant Gel Materials as Potential Drug Carriers

Macroporous physical poly(vinyl alcohol)-based (PVA) cryogels were prepared originating from the dimethylsulfoxide solutions of the polymer that contained urea additives. The variables of the cryotropic gel-formation process were its temperature and the concentration of the added urea, which caused the increase in the rigidity and heat endurance of the resultant cryogels, as well as promoted widening of the macropores in the gel matter. Subsequent rinsing of the DMSO-swollen cryogels with the water excess resulted in the water-swollen PVA cryogels with simultaneous further increase in their rigidity. These gel matrices were tested with respect of their potential to operate as the polymeric carriers in the drug delivery systems. Loading of such water-swollen cryogels with a model drug, ε-amino caproic acid, and then studies of its release kinetics revealed that urea content in the initial PVA solutions used for the freeze-thaw-induced formation of the DMSO-swollen cryogels played the key role for the release characteristics of the drug-loaded water-swollen gel carrier. Namely, PVA cryogels prepared in the presence of a higher concentration of urea possessed the larger pores and, as a result, the drug release occurred somewhat faster.

The impact of the mulberry (Morus nigra L.) leaf extract on the physicochemical properties of poly(vinyl alcohol) blend films

In this work, mulberry (Morus nigra L.) leaf extract was added in poly(vinyl alcohol) (PVA)-based films and its impact on the film’s properties was evaluated. In addition, HCl and glycerol were studied for their use as additives to prepare PVA-based films. The results showed that HCl and glycerol have minimal impacts on the films’ appearance, while mulberry leaf extract imparted green colour to the films produced, mainly due to the presence of green pigments. Moreover, the results suggested that a significant interaction has occurred between the polymer matrix and leaf extract, contributing to a more compact and uniform film morphology. The tensile strengths of the films increased from 21.38 to 28.28 MPa after the addition of mulberry leaf extract. Additionally, the films were tested for their application as food wrapping films. Overall, the results showed that PVA-based films incorporated with mulberry leaf extract have higher capability to preserve the freshness of food when compared to commercial cling wraps from brands such as Diamond and Glad. Appropriate proportions of additives (mulberry leaf extract, HCl and glycerol) used in the formulation of P-GH-M20 films showed improvement in its mechanical properties and food preservation capability.

Synthesis and Physicochemical Properties of Poly[2‐(1‐methylbut‐1‐en‐1‐yl)aniline] and Its Copolymers

AbstractThe progress in organic electronics is closely related to the development of new materials. This study reports the syntheses of hitherto unknown (co)polymers based on aniline and its ortho‐substituted derivative, 2‐(1‐methylbut‐1‐en‐1‐yl)aniline. Electric conductivity, morphology, solubility, electrochemical properties, spectral and thermal characteristics of all the specimens have been studied. A comparative analysis with polyaniline has been performed, and a possible practical usage in resistive‐type moisture sensors has been shown. It has been found that as the content of the substituted monomer units in the (co)polymers grows, the solubility, photoluminescence, and sensitivity of moisture sensors are enhanced. The employment of the (co)polymers obtained as an active material in moisture sensors has shown that the electric conductivity is highly sensitive to changes in ambient moisture. This study has shown that copolymerization of aniline with its ortho‐substituted derivatives is an efficient technique to modify PANI that allows one to enhance the process characteristics of the resulting materials.

Composites of Poly(vinyl chloride) with Residual Hops after Supercritical Extraction in CO2.

The common applications of poly(vinyl chloride) (PVC) in many industries mean that the topic of recycling and disposal of post-consumer waste is still very important. One of the methods of reducing the negative impact of PVC waste on the natural environment is to use technological or post-consumer waste of this polymer to produce new composite materials with favorable utility properties, with the addition of natural fillers, among which agro-waste, including hop residue, is deserving of special attention. In this study, the effect of the addition of residual hops (H) on the mechanical and physicochemical properties of poly(vinyl chloride) was investigated. PVC blends containing 10, 20 and 30 wt % of hop residue were mixed in an extruder, while the specimens were obtained by the injection molding method. It was observed that the addition of H increased their thermostability, as shown by a Congo red test. Furthermore, thermogravimetric analysis showed that the degradation rate of PVC/H composites in the first and second stages of decomposition was lower in comparison with unmodified PVC. In turn, composite density, impact strength and tensile strength decreased significantly with an increasing concentration of filler in the PVC matrix. At the same time, their Young’s modulus, flexural modulus and Rockwell hardness increased. Flame resistance tests showed that with an increasing residual hop content, the limiting oxygen index (LOI) decreased by 9.0; 11.8 and 13.6%, respectively, compared to unfilled PVC (LOI = 37.4%). In addition, the maximum heat release rate (pHRR) decreased with an increasing filler content by about 16, 24 and 31%, respectively. Overall, these composites were characterized by a good burning resistance and had a flammability rating of V0 according to the UL94 test.

Assessment of encrustation and physicochemical properties of poly(lactide-glycolide) - Papaverine hydrochloride coating on ureteral double-J stents after long-term flow of artificial urine.

Implantation of ureteral stents is associated with inconvenience for the patient, which is related to the natural ability of the ureter to contract. The most frequently used solution is the systemic administration of a diastolic drug, which has a relaxing effect on smooth muscle cells and decreases inconvenience. Current interdisciplinary research aimed at reducing the complications after the implantation of ureteral stents used in the treatment of upper urinary tracts with regard to infection, initiation of encrustation, and fragmentation of stents, and patient pain has not been resolved. This study presents the results of research regarding the impact of a biodegradable coating with the active substance on the physical and chemical properties of ureteral stents used in the treatment of the upper urinary tract. The surface of polyurethane double-J stents was coated with poly(lactide-glycolide) (PLGA) 85/15 loaded with papaverine hydrochloride (PAP) with diastolic properties. The coating for ureteral stents has been designed for short-term implantation. The effect of the coating on the process of encrustation and PAP release by the dynamic in vitro model with artificial urine (AU) up to 30 days was evaluated. The influence of AU on the physical and chemical properties of ureteral stents was determined. As part of the study, surface structure and topography researches; chemical composition analyses using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and wetting; and surface roughness studies of both PUR stents and coated stents were carried out. The proposed biodegradable PLGA+PAP coating is characterized by controlled drug release, while optimal physicochemical properties does not increase the encrustation process.

Dielectric Properties of Shrinkage-Free Poly(2-Oxazoline) Networks from Renewable Resources.

In the course of this study, the dielectric and physicochemical properties of poly(2-oxazoline) (POx) networks from renewable resources were compared with those of fossil-based polyamide 12 (PA 12) networks. POx was synthesized by the energy-efficient, microwave-assisted copolymerization of 2-oxazoline monomers, which were derived from fatty acids of coconut and castor oil. For the preparation of composites, aluminum nitride nanoparticles n-AlN and microparticles μ-AlN as well as hexagonal boron nitride BN submicroparticles were used. Additionally, 0, 15, or 30 wt.% of a spiroorthoester (SOE) were added as an expanding monomer aiming to reduce the formation of shrinkage-related defects. For the crosslinking of the polymers and the SOE as well as the double ring-opening reaction of the SOE, a thermally triggered dual-cure system was developed. The fully-cured blends and composites containing SOEs exhibited lower densities than their fully-cured SOE-free analogues, which was indicative of a lower extent of shrinkage (or even volumetric expansion) during the curing reaction, which is referred to as relative expansion RE. The RE amounted to values in the range of 0.46 to 2.48 for PA 12-based samples and 1.39 to 7.50 vol.% for POx-based samples. At 40 Hz, the “green” POx networks show low loss factors, which are competitive to those of the fossil-based PA 12.

ZnO NPs Doped PVA/Spathodea campanulata Thin Films for Food Packaging

The present study aims to investigate the influence of Zinc Oxide nanoparticles (ZnO NPs) on the physicochemical properties of poly(vinyl alcohol)/Spathodea campanulata bud fluid (PSC) matrix. The FITR study assured the physical interaction between ZnO NPs and the PSC matrix. Tensile strength was enhanced by 18% with the incorporation of ZnO NPs into the PSC matrix. The DSC measurements depicted an increased glass transition temperature than PSC matrix at lower content of ZnO NPs. The thermal stability of nanocomposite films was remarkably improved (about 50 °C). The XRD results depicted the homogeneous distribution of ZnO NPs in the PSC matrix. The morphology studies revealed the homogeneity due to good dispersion of ZnO NPs. The water contact angle findings shown the nanocomposite films were hydrophilic. The nanocomposites have shown only 2.8% solubility in water. The WVTR of nanocomposite films was improved by 56%. The bionanocomposite films exhibited good antibacterial activity and excellent preservation capacity and could be a potent alternative to the nonbiodegradable packaging material.

Synthesis and physicochemical properties of poly[2-(cyclohex-2-en-1-yl)aniline] as a new polyaniline derivative

A new polyaniline derivative, poly[2-(cyclohex-2-en-1-yl)aniline], was synthesized using different synthetic parameters.

Synthesis and Physicochemical Properties of Poly(2-ethyl-3-methylindole)

Intramolecular acid-catalyzed cyclization was suggested for the first time for a polyaniline derivative, namely, poly[2-(2-chloro-1-methylbut-2-en-1-yl)aniline] (PClPA), to give hitherto unknown po...