Journal of Applied Polymer Science Research Papers (original) (raw)

2025, Journal of Engineered Fibers and Fabrics

In this work, ZnO microparticles were in situ in the chitosan – attached cotton fabric following ‘equilibration – cum - hydrothermal’ approach to yield zinc oxide microparticles loaded cotton (ZOMLC) fabrics. The ZnO microparticles were characterized by surface plasmon resonance (SPR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The ZOMLC fabric showed fair antibacterial action against model bacteria E.coli.

2025, Journal of Applied Polymer Science

ABSTRACTSuspensions of polyetheretherketone (PEEK) using mixture of ethanol and isopropanol as solvent were prepared to carry out PEEK electrophoretic deposition (EPD). The rheological behavior and suspension structure of PEEK particles dispersed in co‐solvents were investigated over a range of pH values (1–10) and shear rates (γ = 101−3 × 102 s−1). These PEEK suspensions generally exhibited a pseudoplastic flow behavior, indicating the occurrence of particle aggregation in the liquid medium. The maximum solids fraction (ϕm) showed an estimated value of ϕm = 2.9 wt %. Using a suspension with 3 wt % PEEK concentration, PEEK coatings on stainless steel substrates were obtained by EPD at constant voltage condition. The influence of the electrolyte conductivity on PEEK EPD from ethanol–isopropanol suspensions was studied. Experimental results showed that high‐conductivity ethanol‐based suspensions yield non‐uniform deposits, while low‐conductivity suspensions resulted in uniform coatin...

2025, Journal of Applied Polymer Science

Polysaccharides have been widely used for the development of drug delivery systems. These systems can be physicochemically modified to enhance their stabilities and control their drug release profiles. However, such modifications cannot alter their biocompatibility or toxicity. Herein, four structurally modified sodium alginate/carboxymethylcellulose blends are synthesized and loaded with prednisone, and the effects of the modifications on their hydrolytic degradation rates, biocompatibilities, toxicities, and drug release profiles are investigated. All the blends are ionically cross‐linked with Ca2+ and Fe3+. Blend 1 is not modified further, blend 2 is additionally reinforced with 8% w/w of cellulose nanocrystals, blend 3 is treated with epoxidized linseed oil to develop a hydrophobic layer, and blend 4 is chemically cross‐linked with epichlorohydrin. Blends 2 and 4 exhibit similar physicochemical characteristics, appropriate hydrolytic degradation rates and drug release patterns, ...

2025, Journal of Applied Polymer Science

The influence of the presence of CaCO3 on the cure reaction of the epoxy network diglycidyl ether of bisphenol A with isophorone diamine has been studied. The total enthalpy of reaction, the glass transition temperature and the partial enthalpies at different isothermal temperatures have been determined using differential scanning calorimetry (DSC) in dynamic and isothermal mode. A kinetic model accounting the influence of the diffusion of the reactive groups at high conversions was used. All the kinetic parameters have been compared with those of the system without filler (CaCO3). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

2025, Journal of Applied Polymer Science

The physical aging of the epoxy network consisting of a diglycidyl ether of bisphenol A (BADGE n ¼ 0), m-xylylenediamine (m-XDA), and calcium carbonate was studied by differential scanning calorimetry. The glass transition temperature and the variation of the specific heat capacities were calculated using the method based on the intersection of both enthalpy-temperature lines for glassy and liquid states. The apparent activation energy was calculated using a single method that involved separate temperature and excess enthalpy dependency. All calorimetric data were compared with those obtained for the epoxy network without filled calcium carbonate. V

2025, Journal of Applied Polymer Science

The aim of this work was to enhance poly(lactic acid)'s (PLA) flexibility and ductility by blending it with another bioplastic. Poly(trimethylene malonate) (PTM), developed as part of this study, was synthesized from 1,3-propane diol and malonic acid via melt polycondensation. Blend films of PLA and PTM were prepared by solvent casting from chloroform. Differential scanning calorimetry and thermogravimetric analysis were used to show shifted phase transitions and a single glass-transition temperature, indicating miscibility of PTM in the blend films. Morphology and mechanical characterizations of the PLA/PTM blend films were performed by atomic force microscopy using a quantitative nanomechanical property mapping mode, tensile testing, and scanning electron microscopy. Miscible blends exhibited Young's modulus and elongation at break values that can significantly extend the usefulness of PLA in commercial applications. The blending of PTM with PLA resulted in films with a 27-fold increase in toughness compared with neat PLA film. V

2025, Journal of Applied Polymer Science

Carboxymethyl cellulose (CMC) was synthesized from knitted rags, a cellulosic wastes of textile and garment industries, in aqueous ethanolic sodium hydroxide and subsequently mono‐chloroacetic acid reaction medium. A low substituted to high substituted products was obtained from single step up to seven steps carboxymethylation of cellulose. In this way, it was possible to produce low cost and different grades or substituted carboxymethylation derivatives of cellulose. Solubility, degree of substitution (DS), CMC content, and molecular weight of CMC were increased gradually with the increase of the number of reaction steps, although fourth step attained optimal. The DS of CMC from one to seven reaction steps was 0.91–2.84, respectively. Similarly, CMC content and molecular weight of CMC were 72.60%–85.00% and 153,886–252,231, respectively. Grafting of CMC film with methyl methacrylate (MMA) improved strength properties, but it decreased moisture content due to the incorporation of hy...

2025, South African Journal of Chemical Engineering

In the present work, a series of polymeric hydrogels composed of 2-hydroxyethyl methacrylate (HEMA) and three types of cross-linking agents, namely 1,6-hexanediol diacrylate (HDODA), ethylene glycol dimethacrylate (EGDMA), and triethylene glycol dimethacrylate (TEGDA), were synthesized by free radical photopolymerization. The cross-linking agents were used to obtain hydrophilic polymers. The cross-linked polymers have improved resistance to chemical and thermal degradation. The structures of polymeric hydrogels have been investigated intensively using FTIR to verify the obtained structures. Mechanical properties, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were performed. The mechanical properties indicate that the introduction of TEGDA into hydrogel has the highest stress and strain, and the cross-linking using TEGDA achieves the best Young's modulus of elasticity at low water content compared to EGDMA and HDODA cross-linking. The results of TGA show that the incorporation of TEGDA and HDODA into the hydrogel structures increases the onset temperatures to 280 • C and 275 • C, respectively, compared to EGDMA, which has an onset temperature of around 190 • C. The equilibrium water content (EWC%) was measured at different experimental conditions, and results showed that HDODA gives the highest water content of 37 %, while TEGDA gave the lowest water content of 31 %.

2025, InTech eBooks

The aim of this work was to develop the novel glass fiber-reinforced polyester hybrid composites (PHCs) filled with micro-sized titania (TiO 2 ) particles and investigate their functional, mechanical and thermal behaviors. To equip PHCs of unsaturated polyester resin (UPR) with multifunctional characteristics, TiO 2 particles (1-5 wt.%) were dispersed with high disperser homogenizer using hand lay-up process (HLUP), combined with compression molding technique (CMT). The interactions (cross linking and hydrogen bonding) between polymeric chains, styrene, silica contents of glass fiber and TiO 2 particles in PHCs were confirmed by Fourier transform infrared spectroscopy (FTIR). The mechanical and thermal properties increased brilliantly by potential utilization of TiO 2 particles. The 3 wt.% of TiO 2 -imbedded PHCs showed remarkable progress in tensile strength (46 MPa) as well as tensile modules (2.9 GPa) relative to unloaded PHCs. The 5 wt.% of TiO 2 -imbedded PHCs showed 61 and 64% increase in impact energy and hardness, respectively. Thermo-gravimetric analysis (TGA) showed that controlled PHC-0 had the mass loss up to 50%, which was restricted to 17% by using TiO 2 particles for PHC-5. Hence, it was inferred that micro-sized TiO 2 was encouraging filler for incremental valuation in functional, mechanical and thermal characteristics of PHCs. After finding the marvelous mechanical and thermal properties of PHCs, it is endorsed that these polyester composites can be tested for high strength and high temperature applications.

2025, Journal of Vinyl and Additive Technology

Waste poly(ethylene terephthalate) (W‐PET)/acrylonitrile‐butadiene‐styrene (ABS) blends were prepared with a variety of compositions at several rotor speeds in an internal mixer, replacing ABS with different maleated ABS (ABS‐g‐MA) samples in compatibilized blends. A Box–Behnken model for three variables, with three levels, was chosen for the experimental design. ABS‐g‐MA‐based samples exhibited finer particles with a more uniform particle size distribution than ABS‐based ones, as a consequence of the compatibilizing process. Rheological results implied a greater elastic nature for compatibilized blends which increased in the presence of more ABS content; the same trend was observed for complex viscosity. With increasing ABS‐g‐MA or MA concentration, more shear thinning behavior was observed similar to that of ABS; whereas the uncompatibilized blends showed Newtonian behavior like that of W‐PET. The observed shifting in TgW‐PET and TgABS obtained from dynamic mechanical thermal anal...

2025, Journal of Applied Polymer Science

In this work, vapor‐grown carbon nanofibers (CNFs) were functionalized using an optimized route and dispersed in the matrix of carbon fabric‐reinforced epoxy composites to develop multiscale carbon/epoxy composites. Functionalization was carried out through an oxidative treatment with a mixture of HNO3/H2SO4 (1 : 3) using a combination of ultrasonication and magnetic stirring. Functionalized CNFs (F‐CNFs) were characterized for their morphology, length, functional groups, and degradation due to oxidative treatment. The results showed that it was possible to efficiently functionalize CNFs without any degradation through proper selection of treatment duration. F‐CNFs were dispersed homogeneously into the epoxy matrix using ultrasonication in combination with high‐speed mechanical stirring. The incorporation of 0.1 wt % F‐CNFs led to a 65% increase in Young's modulus and a 36% in tensile strength of neat carbon/epoxy composites. The fracture surfaces were studied using scanning ele...

2025, Polymer Engineering & Science

Polarized Raman microspectroscopy has been used to study oriented‐skin layers induced in injection‐molded isotactic polypropylene (iPP) parts. A method based on the intensity sensitivity of several Raman bands to laser light polarization was employed to estimate the degree of molecular orientation in iPP. The skin‐core molecular orientation heterogeneity in injection‐molded iPP is then evaluated via two different experimental methods. Results show that an in‐depth profile using micro‐Raman confocal technique is as valuable as an edge profile performed on a sample cross‐section because both are correlated with optical microscopy measurements. Both Raman measurements are in good agreement with optical microscopy measurements. The skin development was found to be narrowly related to the shear strain rate at the mold walls. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

2025, Bulletin of the American Physical Society

Submitted for the MAR15 Meeting of The American Physical Society Differential Scanning Calorimetry Investigations on Polyvinylidene Fluoride -Fe 3 O 4 Nanocomposites SAMANTHA SALINAS, ROBERT JONES, DORINA M. CHIPARA, MIRCEA CHIPARA, The University of Texas Pan American -Nanocomposites of polyvinylidene fluoride (PVDF)-magnetite (Fe 3 O 4 ) with various weight fractions of nanofiller (0%, 0.2 %, 0.6 %, 1.2%, 2.4 %, 5.8 %, 12 %, 23 %, and 30 % ) have been obtained via melt mixing by loading PVDF with Fe 3 O 4 particles (average size 75 nm from Nanostructured & Amorphous Materials, Inc). Thermal stability of PVDF-Fe 3 O 4 has been investigated by TGA in nitrogen. The increase of the thermal stability of PVDF due to the loading with Fe 3 O 4 was quantified by the shift of the temperature at which the (mass) degradation rate is maximum as a function of Fe 3 O 4 content. The effect of the nanofiller on the crystallization of PVDF was investigated by isothermal DSC (TA Instruments, Q500). Non isothermal DSC tests, (at various heating rates ranging from 1 to 25 • C/min) have been used to locate the glass, crystallization, and melting temperatures. The dependence of the glass, crystallization, and melting temperatures on the concentration of nanoparticles is reported and analyzed in detail. The data are critically analyzed within the classical Avrami theory.

2025, Journal of Applied Polymer Science

Thermogravimetric analysis of polyethylene oxide (powder and nanofibers obtained by force spinning water or chloroform solutions of polyethylene oxide) was studied using different theoretical models such as Friedman and Flynn‐Wall‐Ozawa. A semiempirical approach for estimating the “sigmoid activation energy” from the thermal degradation was suggested and confirmed by the experimental data on PEO powder and nanofibers' mats. The equation allowed for calculating a “sigmoid activation energy” from a single thermogram using a single heating rate without requiring any model for the actual complex set of chemical reactions involved in the thermal degradation process. For PEO (powder and nanofibers obtained from water solutions), the “sigmoid activation energy” increased as the heating rate was increased. The sigmoid activation energy for PEO mats obtained from chloroform solutions exhibited a small decrease as the heating rate was increased. Thermograms' derivatives were fitted to...

2025, Bulletin of the American Physical Society

2025

Tercopolymer (8-HQBF) prepared by condensation of 8hydroxyquinoline (8-HQ) and biuret (B) with formaldehyde (F) in the presence of 2M HCI as catalyst was proved to be a selective chelating ion-exchange tercopolymer for certain metals. Chelating ion-exchange properties of this tercopolymers are studied for Fe•, Cu•, Ni •, Co•, Zn •, Cd+ and Pb+ ions. A batch equilibrium method has been employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion . The study has been carrie<:~ out over a wide pH range and in media of various ionic strengths. The polymer shows a higher selectivity for Fe• , Cu • and Ni+ ions than for Co• , Zn • , Cd+ and Pb+ ions.

2025, Progress in Crystal Growth and Characterization of Materials

Copolymers (2-HAOF) synthesized by the condensation of 2-hydroxy-acetophenone and oxamide with formaldehyde in the presence of acid catalyst and using varied molar ratios of reacting monomers. Copolymer resin compositions have been determined on the basis of their elemental analysis. The number average molecular weights of these copolymers were determined by conductometric titration in non-aqueous media. The viscosity measurements in dimethylformamide (DMF) carried out in order to ascertain the characteristics functions and constants of copolymers. The copolymer resins have been further characterized by absorption spectra in non-aqueous medium, infrared (IR) spectra and nuclear magnetic resonance (NMR) spectral studies.

2025, Progress in Crystal Growth and Characterization of Materials

Tercopolymer (8-HQBF) prepared by condensation of 8hydroxyquinoline (8-HQ) and biuret (B) with formaldehyde (F) in the presence of 2M HCI as catalyst was proved to be a selective chelating ion-exchange tercopolymer for certain metals. Chelating ion-exchange properties of this tercopolymers are studied for Fe 3 •, Cu 2 •, Ni 2 •, Co 2 •, Zn 2 •, Cd 2 + and Pb 2 + ions. A batch equilibrium method has been employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion . The study has been carrie<:~ out over a wide pH range and in media of various ionic strengths. The polymer shows a higher selectivity for Fe 3 • , Cu 2 • and Ni 2 + ions than for Co 2 • , Zn 2 • , Cd 2 + and Pb 2 + ions.

2025, Journal of Applied Polymer Science

A copolymer (4‐HAOF) prepared by condensation of 4‐hydroxyacetophenone and oxamide with formaldehyde in the presence of an acid catalyst proved to be a selective chelating ion‐exchange copolymer for certain metals. Chelating ion‐exchange properties of this copolymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Pb2+, and Hg2+ ions. A batch equilibrium method was employed in the study of the selectivity of metal‐ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe3+ ions than for Co2+, Zn2+, Cd2+, Pb2+, Cu2+, Ni2+, and Hg2+ ions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 787–790, 2003

2025, Journal of Applied Polymer Science

opolymer resins (p-COF) synthesized by the condensation of p-cresol and oxamide with formaldehyde in the presence of acid catalyst, were proved to be selective chelation ion-exchange copolymers for certain metals. The chelating ion-exchange properties of these copolymers were studied for Fe(III), Cu(II), Ni(II), Co(II), Zn(II), Cd(II) and Pb(II) ions in the form of their metal nitrate solutions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range, shaking time and in media of various ionic strengths of different electrolytes. The copolymer showed a higher selectivity for Fe(III), Cu(II) and Ni(II) ions than for Co(II), Zn(II), Cd(II) and Pb(II) ions. Distribution ratios (D) of metal ions were found to be increased by increasing pH of the solutions; hence the resin can be used to recover certain metal ions from waste solutions and used for the purpose of purification of waste water and removal of iron from boiler water. The ion-exchange capacity of metal ions has also been determined experimentally and compared with other commercial resins. Besides ion-exchange properties, the copolymer resins were also characterized by viscometric measurements in dimethyl sulphoxide (DMSO), UVvisible absorption spectra in non-aqueous medium, infra-red spectra and nuclear magnetic resonance spectra. The physico-chemical and spectral methods were used to elucidate the structures of p-COF resins. The morphology of the copolymers was studied by scanning electron microscopy, showing amorphous nature of the resins therefore can be used as a selective ion-exchanger for certain metal ions.

2025, Journal of Applied Polymer Science

A copolymer resin (p-APDF) has been synthesized using the monomers p-aminophenol, dithiooxamide, formaldehyde in 1 : 1 : 2M proportions in the presence of 2M HCl as catalyst. The structure of p-APDF copolymer has been elucidated on the basis of elemental analysis and various physicochemical techniques, i.e., UV-visible, FTIR, and 1 H-NMR spectroscopy. The number average molecular weight of copolymer resin was determined by nonaqueous conductometric titration in DMF. Viscosity measurement were carried out in DMF indicate normal behavior. The prepared resin proved to be a selective ion exchange resin for some metal ions. The chelating ion exchange properties of this resin was studied for Fe(III) and Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Pb(II) ions. A batch equilibrium method was used to study selectivity of metal ion uptake over a wide pH range and in media of various ionic strength. The resin showed a higher selectivity for Fe(III), Ni(II), Cu(II) ions than for Co(II), Pb(II), Zn(II), and Cd(II) ions. V

2025, Journal of Applied Polymer Science

Terpolymer resins (2-HAMF) were prepared by the condensation of 2-hydroxyacetophenone and melamine with formaldehyde in the presence of acid catalyst and using varied molar ratios of reacting monomers. Compositions of terpolymers have been determined by elemental analysis. The number average molecular weights (Mn) have been determined by conductometric titration in nonaqueous medium. Viscometric measurements in dimethyl sulfoxide have been carried out with a view to ascertain the characteristic functions and constants. Electronic spectra, infrared and nuclear magnetic resonance spectra were studied to elucidate the structure.

2025, Journal of Applied Polymer Science

Terpolymer resins (8‐HQDF) were synthesized by the condensation of 8‐hydroxyquinoline (8‐HQ) and dithiooxamide (D) with formaldehyde (F) in the presence of acid catalyst and using varied molar ratios of reacting monomers. Terpolymer resins compositions have been determined on the basis of their elemental analysis and the number average molecular weights of these resins were determined by conductometric titration in non‐aqueous medium. Viscometric measurements in dimethyl formamide (DMF) have been carried out with a view to ascertain the characteristic functions and constants. The UV‐visible, FTIR, and proton nuclear magnetic resonance (H+ NMR) spectra were studied to elucidate the structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

2025, Journal of Applied Polymer Science

Terpolymer resins (2,4‐DHBPOF) were synthesized by the condensation of 2,4‐dihydroxybenzophenone and oxamide with formaldehyde in the presence of acid catalyst and using varied molar ratios of reacting monomers. Terpolymer resins composition has been determined on the basis of elemental analysis and the number average molecular weight of these resins was determined by conductometric titration in nonaqueous medium. Viscometric measurements in N,N‐dimethyl formamide have been carried out with view to ascertain the characteristic functions and constants. UV–visible, IR and NMR spectra were studied to elucidate the structure. The ion‐exchange study of the prepared resin was checked by batch equilibrium method with selected metal ions, Cu2+, Hg2+, Cd2+, Co2+, Zn2+, Ni2+, Pb2+, and Fe3+ at varying electrolyte concentration, pH and time. It is found that, resin can be used as ion exchanger. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

2025, Desalination and Water Treatment

Terpolymer resin 2,4-DHPOF-II was synthesized by the condensation of 2,4-dihydroxypropiophenone (2,4-DHP) and oxamide (O) with formaldehyde (F) in the presence of 2 M HCl as catalyst at 126±1°C. Terpolymer was characterized by UV-visible, IR, 1 H NMR spectral and thermal analysis. It is proved to be a selective chelating ion exchange terpolymer for Fe 3+ , Cu 2+ , Hg 2+ , Ni 2+ , Co 2+ , Zn 2+ , Cd 2+ and Pb 2+ metal ions. Chelating ion-exchange properties of synthesized terpolymer were studied for above mentioned metal ions. A batch equilibrium method was employed to study the selectivity of metal ion's uptake involving the measurements of distribution of given metal ion between sample and solution. Study was carried out using different parameters like pH range, shaking time and media of various ionic strengths.

2025, Journal of Applied Polymer Science

Diamine amic acids were synthesized by reacting aromatic diamines with pyromellitic dianhydride in dimethylacetamide/dioxane. High molecular weight polyamide-amic acids were prepared by low-temperature solution polymerization of diamine amic acids with isophthaloyl chloride in dimethylacetamide. The cyclodehydration of polyamide-amic acids to the corresponding polyamide-imides was accomplished by heating the cast films at 175°C for 3 h. The polyamide-imides were soluble in polar aprotic solvents like dimethylformamide, dimet.hylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone and could be cast into tough and Aexible films. They were characterized by elemental analyses, inherent viscosities, IR, and 'H-NMR spectra. The glass transition temperatures of polyamide-imides were determined by differential scanning calorimetry. The thermal stabilities of the polymers were measured by thermogravimetric analyses in air.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

Several new polyurethane networks based on hyperbranched polyesters (trade name Boltorn ® ) were synthesized to investigate the influence of the hyperbranched crosslinking agent on molecular dynamics of the linear segments containing urethane groups. For comparison, linear polyurethanes as well as polyurethanes crosslinked with the classical crosslinker trimethylolpropane were prepared. Broadband dielectric spectroscopy, dynamic mechanical analysis, and differential scanning calorimetry yielded consistent results concerning molecular relaxation processes; however dielectric spectroscopy appears to be more sensitive concerning the secondary relaxation processes. In the temperature range up to 150 o C, the molecular relaxations were very similar in all the investigated samples, despite considerable structural differences. The weak influence of the crosslinking on the molecular properties could be explained by the existence of hydrogen bonds forming a physical network, which was very dense in this temperature range in comparison with the chemical crosslinks and therefore dominated the molecular mobility in all the investigated systems. This hypothesis was confirmed by rheological measurements performed at temperatures above 150 o C, when the hydrogen bonds should be thermally destroyed. At these temperatures, the effect of crosslinking was manifested by a strong shift of the flowing point: in the linear polyurethanes, this point occurred at much higher frequencies (and lower temperatures) than in the crosslinked analogues.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2025, Analytical and bioanalytical chemistry

The reactivity of melamine-urea-formaldehyde resins is of key importance in the manufacture of engineered wood products such as medium density fibreboard (MDF) and other wood composite products. Often the MDF manufacturing plant has little available information on the resin reactivity other than details of the resin specification at the time of batch manufacture, which often occurs off-site at a third-party resin plant. Often too, fresh resin on delivery at the MDF plant is mixed with variable volume of aged resin in storage tanks, thereby rendering any specification of the fresh resin batch obsolete. It is therefore highly desirable to develop a real-time, at-line or on-line, process analytical technology to monitor the quality of the resin prior to MDF panel manufacture. Near infrared (NIR) spectroscopy has been calibrated against standard quality methods and against (13)C nuclear magnetic resonance (NMR) measures of molecular composition in order to provide at-line process analyt...

2025, Crystals

To assess the application potential of novel biomaterials, their behaviour in model media and upon sterilization should be investigated, as well as the stability related to their storage conditions. Such data are lacking for Mg-substituted HAP (Mg-HAP). Therefore, the changes in the local structure of non-substituted and Mg-HAP after irradiation and immersion in corrected simulated fluid and saline solution for 28 days were followed by electron paramagnetic resonance (EPR) spectroscopy for the first time. To better understand the stability of radical species induced by sterilization, EPR spectra of samples kept for 2 h at temperatures up to 373 K were recorded to provide an insight into the stability of the sample storage conditions by the accelerated aging method. Samples were characterized by PXRD, FTIR, SEM, EDS, AAS and TGA. Results confirmed that irradiation does not induce changes in the composition or the structure of any of the investigated materials. Fading or the complete disappearance of radical signals in the EPR spectra after immersion in both media was accompanied by the disappearance of other phases formed as a minor byproduct in the synthesis of substituted HAP, as confirmed by PXRD and FTIR analysis. Obtained results confirm the great potential of Mg-HAPs for biomedical applications, although closer attention should be given to the processes related to sample storage stability at different temperatures.

2025, Crystals

2025, Environmental Engineering and Management Journal

The dilute solution behavior of a polyelectrolyte with quaternary ammonium salt groups (N,N-dimethyl-2-hydroxypropylenammonium chloride) located along the main chain, (PCA 5 ), has been studied in order to obtain information about the effect of polymer concentration and polarity strength of the solvent onto its chain conformation in various mixtures of water/methanol. The conformational changes of polyelectrolyte chain were followed by viscometric and conductometric methods. The viscometric experimental data were plotted in the terms of Rao's equation. Straight lines were obtained in all cases, allowing the calculation of intrinsic viscosity, [η]. The intrinsic viscosity values decreased with increasing organic solvent content in the mixed solvents. Data from the conductometric studies emphasized the equivalent conductivity values, Λ, increase with decreasing concentration over the whole concentration range. At a given concentration the equivalent conductivity decreases with decreasing dielectric constant. The flocculating efficiency of this polycation on an aqueous suspension of bentonitic clay was also studied.

2025, Journal of Applied Polymer Science

ABSTRACTPolyelectrolyte multilayer films deposited onto various substrates have been used extensively as drug delivery systems. However, little attention has been paid to the release of drugs from free‐standing polymeric films. Herein, we report the construction of thermal crosslinked free‐standing poly(acrylic acid) (PAA)/branched poly(ethyleneimine) (PEI) multilayer films composed of 25 double layers [(PAA/PEI)25] and their use in sorption/release of diclofenac sodium (DS). The (PAA/PEI)25 multilayer films were characterized by scanning electron microscopy, potentiometric titrations and Fourier transform infrared spectroscopy, while the sorption/release of DS was monitored by UV–Vis spectroscopy. The DS sorption equilibrium data were fitted with five isotherm models (Langmuir, Freundlich, Sips, Dubinin–Radushkevich, and Temkin). The maximum equilibrium sorption capacity, qm, given by the Langmuir model was 32.42 mg DS/g. The Korsmeyer–Peppas semiempirical equation showed that the ...

2025, Journal of Applied Polymer Science

Anionic polymerization of various cyclosiloxanes [octamethylcyclotetrasiloxane (D4), 1,3,5,7tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (V4), and hexamethylcyclotrisiloxane (DJ] was performed. As catalysts, IRA-900 and PB-100 type anionites with benzyltrimethylammonium and 3-acrylamidopropylbenzyldimethylammonium groups, respectively, were used. The anionite with higher strongly basic exchange capacity (IRA-900) is more efficient in dimethylcyclosiloxane polymerization. PB-100 anionite with less strongly basic capacity is more active for polymerization of the V4 monomer with bulky and electronegative substituent.

2025, Journal of Applied Polymer Science

The flocculating efficiency of some hydrophilic/hydrophobic cationic polyelectrolytes on montmorillonite suspension in water was investigated as a function of both the polycation structure and the flocculation parameters: polycation/montmorillonite contact time, suspension pH, polycation dose, and temperature. Cationic polyelectrolytes with quaternary ammonium salt groups in the backbone and hydrophobic side chains (hexyloxypropyl, PCA5H1 and PCA5H2; and decyloxypropyl, PCA5D1, respectively) were used as flocculants. The flocculation was time dependent. A negative influence of the stirring time and of the abrupt variation of pH from basic to acidic on the separation efficiency was evidenced. The increase of the polycation dose from 0.58 mg polycation/g montmorillonite up to 1.74 mg/g montmorillonite showed a positive influence on the sedimentation of montmorillonite particles for all the polycations taken into account. The influence of the polycation structure was reflected in the l...

2025, Colloid & Polymer Science

2025, Journal of Applied Polymer Science

ABSTRACTThe specific dependencies of the initial reduced polymerization rate on the initial monomer concentration were introduced for the radical homopolymerization of N‐[3‐(dimethylamino)propyl]acrylamide (DMAPA) and N‐[3‐(dimethylamino)propyl]methacrylamide (DMAPMA) in toluene, DMF, and water at 60 °С. The degree of the monomer self‐association and the ratio of the amides constituting various types of associates were evaluated using FT‐IR spectroscopy and computer simulation for the solutions of DMAPA and DMAPMA in toluene with different monomer concentrations. The hypothesis linking the type of predominant pre‐reaction monomer assemblies and the revealed concentration effects was proposed for the homopolymerization of aminoamide monomers and explaining unconventional experimental data. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44412.

2025, Polymer Science Series B

The parameters of hydrogen bonds formed during acetalization of poly(vinyl alcohol) with buta nal are determined via computer simulation methods. It is shown that alcohol groups involved in the forma tion of intermolecular hydrogen bonds are the least active in acetalization reactions. The kinetics of the ace talization reactions in 2,4 pentanediol-water-butanal and (vinyl alcohol)-water-butanal systems are stud ied at various concentrations of alcohols that model a change in the ratio of hydrogen bonds of various types and are realized in the aqueous solutions of poly(vinyl alcohol) and poly(vinyl butyral). The calculated rate constants are in agreement with the computer simulation based order of reactivity of alcohol groups involved in hydrogen bonds of various types. It is proposed that the reactivity of residual alcohol groups in a poly(vinyl butyral) macromolecule should increase when a certain conversion of the polymer is attained.

2025, Gels

Any thermoset resin’s processing properties and end-use performance are heavily influenced by the gel time. The complicated viscosity of resin as a function of temperature is investigated in this work, with a particular emphasis on identifying the gel point and comprehending polymerization. Rheology studies carried out using a plate-plate controlled stress rheometer under isothermal conditions were used to compare three experimental techniques for figuring out an epoxy resin’s gel point. We also look at the basic modifications that take place during polymerization. We verify the reliability of the three strategies by including Principal Component Analysis (PCA), an unsupervised machine learning methodology. PCA assists in uncovering hidden connections between these methods and various affecting factors. PCA serves a dual role in our study, confirming method validity and identifying patterns. It sheds light on the intricate relationships between experimental techniques and material p...

2025, Journal of polymer science

Degradation products of lignin, a widely available biopolymer, represent the most abundant feedstock for aromatics in nature. In this work, we focused on syringic acid, derived from lignin S-type monolignol, to synthesize different monomers for radical polymerization. The resulting polymers have molecular weight spanning over a wide range, which depends on the monomer, with up to M n = 1,100,000 g.mol -1 and Đ = 3.0. The novel polymers exhibit a thermal stability higher than 350 C and differentiated glass transition temperatures, ranging from 105 to 120 C. One of the monomers synthesized with a free carboxyl group was able to polymerize in water-instead of organic solvent-and resulted in a water soluble polymer. Monomers from syringic acid offer a unique bio-based alternative to oil-based polystyrene in industry for a wider range of application.

2025, Journal of Applied Polymer Science

This article reports on the removal of colloidal suspensions of kaolinite, bentonite, and alumina using chitosan sulfate (ChS). ChS was synthesized by partial introduction of sulfate groups in the chitosan (Ch) structure. The polyampholyte (chitosan sulfate) shows variable charge depending on the pH of the solution. ChS was characterized by FTIR, 13 C-NMR, elemental analysis, and potentiometric titrations. The ChS coagulation-flocculation capacity for kaolinite, bentonite, and alumina aqueous suspensions was systematically studied. The coagulation-flocculation process was carried out at various pH values and ChS concentrations. The pH range in which the largest ChS removal capacity was observed depended on particle type (4.5-5.5 for kaolinite, 4.5-7.0 for bentonite, and 7.0-8.0 for alumina). The removal of colloidal particles is explained by charge neutralization due to electrostatic interactions between ChS and particles and particle entrapping when the polyelectrolyte precipitates. V C 2011

2025, Microscopy and Microanalysis

2025, Journal of Applied Polymer Science

Production of polyester filament involves melt spinning into partially oriented yarn (POY), followed by drawing to enhance the bulk and mechanical properties. The industrial demand of increasing productivity is generally met by increasing POY melt spinning speeds, which is limited by increasing polymer chain orientation (and reducing residual drawability) in the POY produced at higher spinning speeds. Modification of the quench geometry during melt spinning is claimed to allow reduction of air drag and polymer chain orientation, permitting an increase in productivity during melt spinning into POY. We present a simple way for modeling the quenching of molten filaments under the modified (axial) air flow. Numerical simulations of the melt spinning are developed to demonstrate the influence of the quench geometry modification as we compare the process with the conventional cross-flow quench and the modified axial quench. We find that increasing quench air flow reduces the polymer chain orientation, in contrast to the well known effect in cross-flow quench.

2025, Journal of Applied Polymer Science

Experimental data are obtained for the extent of swelling and progress of the step-growth swollen-state polymerization (SwSP ) of polyethylene terephthalate (PET). The SwSP is carried out in biphenyl and diphenyl ether mixture (26 : 74 w/ w) solvent under appropriate conditions designed to understand the factors responsible for enhanced reaction rates. The kinetics rate constants, evaluated in terms of simple model, are found to be 2.5-5 times higher for SwSP as compared to the solid-state polymerization (SSP). As the diffusional/mass transfer effects are eliminated in our experiments, this increase in rate constants can be attributed to increased mobility of reactive chain ends. Polymerization rate is found to be further enhanced by addition of a polycondensation catalyst (Sb 2 O 3 ) to the solvent during SwSP.

2025, Journal of Applied Polymer Science

We report a facile approach for the spontaneous formation of silver nanoparticles in the presence of gum acacia polymer (a natural polymer) without the addition of any typical reducing agent under mild conditions. Silver nanoparticles (∼ 5 nm) have been obtained by the mixing of equal amounts of 0.5 wt % aqueous solutions of acacia and silver nitrate. The formation of silver nanoparticles has been confirmed with ultraviolet–visible, Fourier transform infrared, X‐ray diffraction, and X‐ray photoelectron spectroscopy analyses. Gum acacia polymeric chains promote the reduction process and act as good stabilizers over 5 months. To confirm the formation and stabilization of the nanoparticles, a transmission electron microscope has been employed. The advantage of this methodology is that it is possible to prepare silver nanoparticles without any organic solvents or reducing agents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

2025, Journal of Applied Polymer Science

Nanocomposites of modified chitosan, carboxymethyl chitosan (CMCh) with hydroxyapatite (HAP) have been prepared by coprecipitation technique. Totally three nanocomposites containing 80/20, 50/50, and 20/80 of HAP/CMCh have been prepared and were characterized by using transmission electron microscopy (TEM), X‐ray diffraction (XRD), fourier transformed infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), thermogravimetry (TG), and scanning electron microscopy (SEM). Modified chitosan, CMCh, which is water soluble can be used for drug delivery application. TEM micrographs of the nanocomposites revealed the formation of small HAP crystallites of about 230 nm in length and 30 nm in width that are aggregated to form elliptical shapes or morphology. TGA thermograms showed that the thermal stability of the CMCh increased with incorporation of HAP. FTIR, XRD, and XPS analysis of CMCh/HAP nanocomposites showed the peaks corresponding to CMCh as well as HAP and confirm the fo...

2025, Journal of Applied Polymer Science

We report the preparation and characterization of pure polyaniline nanoparticles (PANI_NPs), zinc oxide nanoparticles (ZnO_NPs), and ZnO_NPs/PANI hybrid inorganic/organic nanocomposites (HION) dispersed in aqueous sodium dodecyl sulfate solutions. We have characterized the HION, which were prepared by the polymerization of aniline in presence of sodium dodecyl sulfate and ZnO_NPs, by dynamic light scattering, zeta potential, Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and scanning electron microscope (SEM). We have obtained ZnO_NPs, PANI_NPs, and ZnO_NPs/PANI with negative values of zeta potential and average diameters of 4.6 nm, 3.6 nm and 8.1 nm, respectively. XRD results reveal that the polymer exhibits a well‐defined crystalline phase, as well as the presence of ZnO in a hexagonal phase. The observed changes in the FTIR spectra of the HION are associated to the formation of hydrogen bonding between the ZnO_NPs and the NH groups present in the PANI chains. Hetero...

2025, Journal of Applied Polymer Science

Fiber‐reinforced composites based on natural fibers are promising alternatives for materials made of metal or synthetic polymers. However, the inherent inhomogeneity of natural fibers limits the quality of the respective composites. Man‐made cellulose fibers (MMCFs) prepared from cellulose solutions via wet or dry‐jet wet spinning processes can overcome these limitations. Herein, MMCFs are used to prepare single fiber epoxy composites and UD composites with 20, 30, 40, and 60 wt% fiber loads. The mechanical properties increase gradually with fiber loading. Young's modulus is improved three times while tensile strength doubles at a loading of 60 wt%. Raman spectroscopy is employed to follow conformational changes of the cellulose chains within the fibers upon mechanical deformation of the composites. The shift of the characteristic Raman band under strain indicates the deformation mechanisms in the fiber. Provided stress transfer occurs through the interface, it is a direct measu...

2025, Journal of Applied Polymer Science

This paper presents data on the preparation and characterization of pure or silanized Al2O3 nanoparticles in poly(ethylene-co-butyl acrylate) (EBA). Two types of Al2O3 nanoparticles, differing in specific surface area, were functionalized using either amino-or octyl-terminated silane. A higher surface coverage was obtained with the amino-terminated silane, compared to the octyl-terminated silane. Functionalized, as well as untreated, nanoparticles were then processed into EBA, containing either 13 or 28 wt. % butyl acrylate (BA), by extrusion compounding. The melting temperature and degree of crystallization of the nanocomposites were similar to those of the unfilled EBA matrixes. The dispersion of all materials was characterized by scanning electron microscopy. The best dispersion was obtained for the octyl-terminated aluminium oxide nanoparticles in EBA containing 13 wt. % BA.