Utilization of ramon seeds (Brosimum alicastrum swarts) as a new source material for thermoplastic starch production

The development and characterization of biodegradable polymers deriving from renewable natural sources has attracted much attention. The aim of this work was to partially characterize a thermoplastic starch obtained from the starch of seeds from the ramon tree (TPS‐RS) as an option to substitute thermoplastic starch from corn (TPS‐CS), in some of its applications. At 55% of relative humidity (RH), TPS‐RS had higher tensile strength and deformation than TPS‐CS. X‐ray diffraction analysis showed similar values in residual crystallinity (percentage of crystallinity that remains after plasticization process) in both TPS. The SEM micrographs showed a few remnant granular structures in the TPS‐RS. The FTIR showed a greater intensity in band at 1016 cm^?1 in the TPS‐CS and TPS‐RS in comparison with their corresponding native starch, indicating an increase in the amorphous region after plasticization. The TGA analysis showed greater thermal stability in TPS‐CS (340 °C) compared with TPS‐RS (327 °C). In addition, the glass transition temperature in both TPS was 24 °C. The results obtained represent a starting point to potentialize the use of TPS‐RS instead of TPS‐CS for the development of new biodegradable materials for practical applications in different areas. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44235.     

Morphology,polymorphism, and metal ion adsorption studies of electrospun nanofibers based on PVDF and organically modified layered double hydroxide

Nonwoven nanofiber mats of polyvinylidene fluoride (PVDF) with modified layered double hydroxide (MLDH) were prepared by electrospinning. The fiber morphology was studied using scanning electron microscopy. X‐ray diffraction and FTIR spectroscopy was used to characterize the polymorphism in electrospun mats. Fibers of diameter in the range 80–800 nm with beads of about 2–3 µm size were observed for pure PVDF, while in case of PVDF/MLDH nanocomposites the number and size of beads were found to be significantly reduced. Uniform and fine nanofibers were obtained at lower content of MLDH, but slightly rough surface was seen for higher content. FTIR and X‐ray diffraction patterns signify various crystalline forms of electrospun PVDF. The content of polar β‐crystalline phase of PVDF, which exhibit piezo and ferroelectric properties was found to be enhanced significantly due to reinforcement of MLDH. Use of these nanofiber mats for heavy metal Cu (II) removal was explored. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4508–4515, 2013     

Photoinitiated grafting of glycidyl methacrylate and methacrylic acid on ground tire rubber

Ground tire rubber (GTR) films and GTR particles were surface‐functionalized by glycidyl methacrylate and methacrylic acid through photoinitiated grafting. The grafting yield of GTR films was determined by Fourier transform infrared spectroscopy with attenuated total reflection (FTIR‐ATR). For the calibration of the FTIR‐ATR data, X‐ray photoelectron spectroscopy was used. The presence of epoxy and carboxyl groups on the GTR surface was demonstrated by contact‐angle measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1622–1630, 2003     

A facile route for the synthesis of nanotubular composite of polyaniline with cobalt and its superparamagnetism below blocking temperature

We have prepared nanotubular composite of polyaniline with cobalt from the reverse micelle of sodium dioctyl sulfosuccinate and n‐hexane. Samples are characterized with characterized by X‐ray diffractometer (XRD), transmission electron microscopy, field emission scanning electron microscope, energy dispersive spectroscopy (EDS), Fourier transformed‐infrared spectrums (FTIR), thermo gravimetric analysis, differential scanning calorimeter, and vibrating sample magnetometer. XRD patterns shows metastable ε‐cobalt phase in the composite. Tube like morphology with average diameter of 25–35 nm and length up to 1 µm is obtained. Peak assignment of FTIR spectrum reveals that green solid material is polyaniline and incorporation of cobalt in polyaniline matrix leads structural change. EDS also indicates the presence of cobalt in the nanocomposite. Enhancement in thermal stability is obtained for nanocomposite. Superparamagnetism is obtained in the nanocomposite from dc magnetic measurement and ac susceptibility measurement. POLYM. COMPOS. 36:489–496, 2015. © 2014 Society of Plastics Engineers     

Preparation of antimicrobial sutures by preirradiation grafting of acrylonitrile onto polypropylene monofilament. III. Hydrolysis of the grafted suture

Polypropylene‐grafted‐polyacrylonitrile (PP‐g‐PAN) sutures were prepared by graft polymerization of acrylonitrile onto polypropylene (PP) monofilament using a preirradiation method. The grafted PP monofilaments were subsequently hydrolyzed to introduce carboxyl groups for antimicrobial drug immobilization. The maximum conversion of nitrile groups into carboxyl groups was limited to about 62% and produced sutures with carboxyl content ranging from 0.042 to 0.25 mmol/g. The physical characteristics of sutures were evaluated by FTIR, X‐ray diffraction, differential scanning calorimetry, and X‐ray photoelectron spectroscopy. In general, the hydrolysis did not cause any significant variation in crystalline structure. The mechanical strength was affected in all the grafted sutures. The tensile strength of sutures was investigated as a function of the degree of grafting. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2509–2516, 2004     

Synthesis of exfoliated PP/LDH nanocomposites via melt‐intercalation: Structure,thermal properties,and photo‐oxidative behavior in comparison with PP/MMT nanocomposites

Exfoliated polypropylene (PP)/layered double hydroxide (LDH) nanocomposites have been successfully synthesized via melt‐intercalation. Their structure, thermal properties, and photo‐oxidative behavior have been characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA), X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectrum. TGA and DMA data show that the PP/LDH nanocomposites have enhanced thermal stability compared with virgin PP and corresponding PP/montmorillonites (MMT) nanocomposites, especially in high temperature range during the thermal decomposition of the samples. XPS and FTIR results give positive evidence that the photo‐oxidation mechanism of PP in the PP/LDH materials is not modified compared with that of virgin PP. However, photo‐oxidation rate of PP/LDH materials is much lower than that of PP and PP/MMT samples, indicating that the PP/LDH nanocomposites have better UV‐stability. POLYM. ENG. SCI. 46:1153–1159, 2006. © 2006 Society of Plastics Engineers     

Synthesis and characterization of a propargyl‐substituted polycarbosilane with high ceramic yield

A propargyl‐substituted polycarbosilane (PCS), namely, propargyl‐substituted hyperbranched hydrodipolycarbosilane (PHPCS), was prepared by a modified synthesis route, which involved Grignard coupling of partially methoxylated Cl₃SiCH₂Cl and CHCCH₂Cl, followed by reduction with lithium aluminum hydride. The resultant PHPCSs were characterized by gel permeation chromatography, Fourier transform infrared (FTIR) spectroscopy, and NMR. Moreover, the thermal properties of the PHPCSs were investigated by thermogravimetric analysis. The ceramic yield of PHPCS at 1400°C was about 82.5%, which was about 10 wt % higher than that of hyperbranched hydrodipolycarbosilane without the substitution of propargyl groups. The PHPCS‐derived ceramics were characterized by X‐ray diffraction (XRD), FTIR spectroscopy, and elemental analysis. The XRD and FTIR results indicate that the heat treatment significantly influenced the evolution of crystalline β‐SiC. It can be convenient to get near‐stoichiometric ceramics from PHPCS through the control of feed ratios of the starting materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121:3400–3406, 2011     

Nanocomposite alkyd coatings

Organophilic montmorillonite intercalants were prepared by a cation‐exchange process between Na⁺ ions of montmorillonite and ammonium salt of octadecylamine. Fourier transform infrared (FTIR) spectrometry and X‐ray diffraction analyses of the compounds were carried out. The layer spacings of both modified and unmodified montmorillonites were calculated with Bragg's law. FTIR and X‐ray profiles showed organophilic characteristics for the modified montmorillonite, the layer spacing of which increased by two orders of magnitude with respect to that of the unmodified montmorillonite. The prepared organoclay was incorporated into an alkyd‐based clear coating, and X‐ray profiles showed an exfoliated structure for the organoclay alkyd coating. The application of the prepared organoclay to alkyd‐based clear coatings showed a significant enhancement of the hardness and impact strength of the coating film compared with those of unmodified montmorillonite equally incorporated into the coating formulations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2639–2642, 2006     

Montmorillonite clay nanocomposites based on vinyl pyridine‐styrene‐butadiene terpolymer (VPR)/acrylonitrile‐butadiene rubber (NBR) blend

This study describes a novel route to synthesize vinyl pyridine‐styrene‐butadiene terpolymer rubber (VP rubber) montmorillonite clay nanocomposites by latex blending technique. The pyridine moiety of the VP rubber was modified with methyl iodide to form the pyridinium ion during latex blending. Cation exchange reaction of the pyridinium ion of the VP rubber latex with sodium montmorillonite occurred during latex stage mixing which helped to form VP rubber‐montmorillonite clay nanocomposites. Coagulation of the latex‐clay slurry produced nanocomposites master batch. The master batch was compounded with acrylonitrile butadiene rubber (NBR). Fourier Transform Infrared Spectroscopy (FTIR) confirmed the modification of the pyridine moiety of VP rubber. Wide angle X‐ray diffraction (WAXD), scanning electron microscopy‐energy dispersive X‐ray spectrophotometry (SEM‐EDS) and transmission electron microscopy (TEM) provided the evidences of formation of nanocomposite. Remarkable improvements in the mechanical properties were found by addition of small amount of modified clay. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Chelating polymer granules prepared by radiation‐induced homopolymerization. II. Characterizations

Characterizations of chelating polymer adsorbent granules, incorporating amidoxime groups based on polyacrylonitrile (PAN), prepared for selective adsorption of uranium and likely other transition metals were studied. PAN was prepared by radiation‐induced polymerization technique and followed by amidoximation reaction. Conversion of PAN into polyacrylamidoxime (PAO) was studied by fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Morphology and thermal properties were also investigated. PAO was investigated in the separation of uranium from iron‐rich silicate rock samples and subjected to x‐ray fluorescence analysis (XRF). Selective adsorption for uranium and low affinity for alkali and alkaline earth metals were observed. The order of selectivity was found to be U ? Cu > Fe > Ni > Cr > V ? Ca > K. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1180–1187, 2006     

Effect of silane‐coupling agents on interfacial properties of CF/PI composites

In this article, to form a structure‐controlled interface, carbon fiber (CF) surfaces were first activated by plasma technique and then hydroxylated by LiAlH₄ treatment, and then were reacted with a suit of silane‐coupling agents terminated with desired functional groups to form thin films, which further reacted with polyimide (PI) resin to generate a strong adhesion interface. The morphology, structure, and composition of CF surfaces before and after treatment were investigated by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS), respectively. The results of FTIR and XPS analysis showed that silane‐coupling agents were successfully chemisorbed onto the CF surfaces by the hydrolysis and condensation reactions. The interfacial shear strength of the CF/PI microcomposites was evaluated by the microbond technique. The results showed that the types of the interfacial functional groups, especially the vinyl end groups in vinyltriethoxysilane (VS), which can react with PI resin, had very significant influence on the improvement of the interfacial adhesion properties of composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Investigation on Brill transition of nylons 6/16, 4/16 and 2/16 by variable‐temperature WAXD and FTIR

Brill transition behaviour of nylons 6/16, 4/16 and 2/16 has been studied systematically by variable‐temperature wide‐angle X‐ray diffraction (WAXD) and real‐time FTIR. It is shown that all nylons investigated undergo Brill transitions before melting on heating. Brill temperatures detected by real‐time FTIR are consistent with the results of variable‐temperature WAXD measurements. In addition, Brill bands were identified based on real‐time IR spectra and further consideration of —NH— groups provided additional information for discussing the mechanism of the crystalline transition. Copyright © 2003 Society of Chemical Industry     

Infrared spectra and ferro‐electricity of ultra‐thin films of vinylidene fluoride and trifluoroethylene copolymer

The structures of ultra‐thin films of vinylidene fluoride and trifluoroethylene copolymer were characterized using Fourier transform infrared reflection absorption spectroscopy (FTIR‐RAS), FTIR transmission spectroscopy (FTIR‐TRS), atomic force microscopy, and wide‐angle X‐ray diffraction. The ferro‐electricity was determined from polarization charge (a displacement (D)–electric field (E) hysteresis). FTIR‐RAS and FTIR‐TRS measurements showed that the molecular chains of polymers (crystal c‐axis) near the substrate tended to align parallel to the substrate. However, thermal annealing of the sample films at temperatures above 145 °C caused a marked change in molecular alignment of the polymer chains (crystal c‐axis) from parallel to normal to the substrate, and, further, caused a conformation change from trans to partially gauche forms. Copyright © 2007 Society of Chemical Industry     

Preparation and properties of magnetic polystyrene microspheres

Magnetic polystyrene nanospheres were efficiently prepared by using a new indirect process based on miniemulsion polymerization of styrene. The samples were characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), and vibrating‐sample magnetometry (VSM), respectively. The experimental results clearly show that the 3‐methacryloxypropyltrimethoxy silane was anchored onto the surface of the magnetic particles to form the vinyl end. The size of the magnetic particle is about 6–30 nm. The size of the magnetic particle capped with polystyrene is about 1–2 μm. The magnetic polystyrene spheres exhibit multidomain character, whereas the pure magnetic particles show single domain character. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3660–3666, 2007     

Controlling the surface wettability of poly(sulfone) films by UV‐assisted treatment: benefits in relation to plasma treatment

Hydrophilic and superhydrophilic surfaces of poly(sulfone) (PSU) thin films were prepared by UV irradiation in the presence of O₂ or acrylic acid (AA) vapor. Treated surfaces were then investigated by water contact angle measurements, Fourier transformed IR spectroscopy in attenuated total reflectance mode (FTIR‐ATR), X‐ray photoelectron spectroscopy (XPS), near‐edge X‐ray absorption fine structure (NEXAFS) and AFM. Water contact angle values of treated PSU films using either O₂ or AA vapor as the reactive atmosphere reached about 6° after more than 120 min of irradiation. FTIR‐ATR, XPS and NEXAFS analysis showed incorporation of oxygenated groups onto the surface that led to its hydrophilic characteristics. In addition, when AA vapor was used as the reactive atmosphere, a photopolymerization process of poly(acrylic acid) onto the surface of the PSU was observed. AFM analysis showed a very low level of roughness after the treatments. A comparison of UV‐assisted surface modifications of PSU films with traditional plasma treatments showed excellent qualitative agreement between the two techniques. Our results show that UV‐assisted treatments in the presence of AA vapor or O₂ are efficient ways of controlling the surface wettability and functionalities grafted on the surface of PSU films. This treatment can be considered as a permanent dry grafting method that resists aging and uses a simple experimental setup. © 2012 Society of Chemical Industry     

Synthesis,characterization, and fluorescence properties of lanthanide complexes with poly(styrene‐co‐methacrylic acid)

A series of new complexes of poly(styrene‐co‐methacrylic acid) with Ln(III) (Ln = La, Eu, Tb) were synthesized and well characterized by means of elemental analysis, FTIR, differential scanning calorimetric (DSC) analysis, TG‐DTA analysis, X‐ray diffraction (XRD), and fluorescence determination. The elemental analysis and FTIR studies showed that a large part of carboxylic groups on the side chain of the copolymer are coordinated with Ln(III) ions. The TG‐DTA and DSC analysis results indicated that the complexes have good thermal stability. XRD experiments showed that copolymers and the complexes are amorphous. Among these complexes, Eu(III) complexes and Tb(III) complexes exhibit characteristic fluorescence with comparatively high brightness and good monochromaticity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of polyaniline–polypyrrole composite from polyaniline dispersions

Polyaniline–polypyrrole (PANI‐PPy) composite was prepared by in situ polymerization of pyrrole in PANI dispersion using FeCl₃·6H₂O as oxidant and sodium dodecyl benzene sulfonate (SDBS) as surfactant. Different synthesis conditions of PANI dispersion including the relative concentration of aniline and SDBS and the amount of acid (HCl) on the morphology and conductivity of the resulting composites were investigated. Fourier transformation infrared (FTIR) spectra, X‐ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), X‐ray diffraction (XRD) patterns, and contact angles of the composites showed there existed certain interaction between PANI (or PANI‐SDBS) and PPy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3523–3529, 2007     

Characterization and adsorption performance of Zr‐doped akaganéite for efficient arsenic removal

BACKGROUND: A new adsorbent, Zr‐doped akaganéite, having a tunnel structure and efficient arsenic adsorption capacity, was prepared by homogeneous co‐precipitation with urea. Formation of the synthesized adsorbent was studied in detail. RESULTS: The adsorbent was characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and the determination of Cl^? leakage showed that an appropriate amount of Zr⁴⁺ was doped into akaganéite (β‐FeOOH) by substitution of Fe³⁺ and possessed a similar tunnel structure to Fe³⁺. The morphology, surface area and tunnel structure changed greatly compared with β‐FeOOH with more ? OH groups and Cl^? introduced into the tunnel structure after doping with Zr⁴⁺. The Zr‐doped β‐FeOOH exhibited highly effective adsorption of arsenic with a capacity for As(III) and As(V) of 120 and 60 mg g^?1 at neutral pH. On the basis of Cl^? release during adsorption and analyses of zeta potential along with XPS and FTIR spectra, the adsorption of arsenic on Zr‐doped β‐FeOOH was verified as inner‐sphere adsorption with the ? OH groups in the tunnel structure of the adsorbent the main adsorption sites at arsenic high concentrations. CONCLUSION: The Zr⁴⁺ was doped into β‐FeOOH by substitution of Fe³⁺. The ? OH groups in the tunnel structure of the adsorbent were the main adsorption sites at high arsenic concentrations, and the adsorption occurred by an inner‐sphere adsorption process. © 2012 Society of Chemical Industry     

The effect of layered double hydroxides dispersion on thermal and mechanical properties of poly(vinyl chloride)/poly(methyl methacrylate) blends

Poly(vinyl chloride) (PVC)/layered double hydroxide (LDH) composites and PVC/poly(methyl methacrylate) (PMMA)/LDH composites were prepared via solution intercalation into PVC using both unmodified and organo‐modified LDHs and variable‐molecular‐weight PMMA as additional components. The LDH dispersion was investigated using X‐ray diffraction analysis and electron microscopy in scanning and transmission modes. Spotlight fourier transform infrared (FTIR) chemical imaging analysis was also used to obtain a deeper insight into the dispersion of polymer phases and LDH segregation. Thermal properties were determined using thermogravimetric analysis and differential scanning calorimetry; moreover, a preliminary investigation of mechanical properties in tensile mode and evaluation of the Vicat softening temperature were carried out. The morphological analysis of PVC/LDH and PVC/PMMA/LDH composites evidenced in both cases the presence of disordered micro‐aggregates with loss of the LDH crystallographic symmetry depending on the amount and molecular weight of PMMA. In particular, in the case of PVC/PMMA/LDH composites, the FTIR imaging analysis showed that PMMA mostly segregated in the LDH phase. However, even if the degree of LDH dispersion was not elevated (micro‐aggregates with disordered structures and size ranging from 0.5 up to 11 µm were evidenced), thermal stability and mechanical properties of the composites were improved with a synergic effect of PMMA and LDH. © 2013 Society of Chemical Industry     

Microstructure,crystallization and dynamic mechanical properties of polyamide/clay nanocomposites after melt‐state annealing

Polyamide 6/clay (PA/clay) nanocomposites produced by melt‐compounding were treated under various melt‐state annealing processes. The effect of melt‐state annealing on the microstructure, crystallization, and dynamic mechanical properties was characterized by transmission electron microscope (TEM), modulated differential scanning calorimetry (MDSC), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and dynamic mechanical analysis (DMA). Clay layers were exfoliated in PA matrix. The crystalline transformation between α and γ‐crystalline phase was virtually dependent on the annealing process and clay loading. After melt‐state annealing between 230 and 250°C, clay induced the appearance of a new endothermic peak in PA/clay. PA/clay after melt‐state annealing exhibited a higher elastic modulus above T_g and a lower β relaxation below T_g as compared with the non‐annealed sample. FTIR analysis demonstrated that the melt‐state annealing caused strong hydrogen bonding interaction of amide groups with clay layers. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers