Maleic Anhydride (maleic + anhydride)

Distribution by Scientific Domains
Distribution within Polymers and Materials Science

Terms modified by Maleic Anhydride

  • maleic anhydride copolymer

  • Selected Abstracts

    Chemoselective and Regiospecific Synthesis of Iminospiro- , -lactones from Maleic Anhydride or Citraconic Anhydride and Alkyl Isocyanides with Dialkyl Acetylenedicarboxylates

    Mohammad Bayat
    Abstract Isocyanides, dialkyl acetylenedicarboxylates (=dialkyl but-2-ynedioates), and anhydrides such as maleic anhydride (=furan-2,3-dione) or citraconic anhydride (=3-methylfuran-2,3-dione) react in one pot to afford novel iminospiro- , -lactones in fairly good yields at room temperature (Schemes,1 and 3). [source]

    A Solvent Free Graft Copolymerization of Maleic Anhydride onto Cellulose Acetate Butyrate Bioplastic by Reactive Extrusion

    Arief C. Wibowo
    Abstract Summary: Interfacial adhesion between fibers and matrix is a crucial factor for effective stress transfer from matrix to fiber; especially in short fiber reinforced composite systems. The use of a chemical compatibilizer is an efficient means to achieve such adhesion. Maleic anhydride-grafted-cellulose acetate butyrate (CAB-g-MA) is one such compatibilizer which can be used in biocomposite fabrication, and this has been synthesized in our laboratory by utilizing a twin-screw reactive extrusion process in the presence of a free radical initiator (2,5-dimethyl-2,5-di(tert -butylperoxy)hexane). The unique feature of this process is its solvent-free approach for grafting of maleic anhydride onto CAB, without hydroxyl group protection. CAB-g-MA was characterized using FTIR as well as by a non-aqueous titration method. The effects of initiator and monomer concentrations and various processing conditions on the graft content were also investigated. The preliminary results show that by adding approximately 10 wt.-% of CAB-g-MA into a plasticized cellulose acetate butyrate (TEB)-industrial hemp fiber biocomposites system, an improvement in tensile strength (20%) and in tensile modulus (45%) were obtained. These results are promising in that they pave the way for future studies involving the use of CAB-g-MA as a suitable compatibilizer for cellulose ester-natural fiber biocomposites. [source]

    Ultrasonically Initiated Grafting of Maleic Anhydride onto Poly(propylene)

    Xiumin Tan
    Abstract This paper presents the studies on the grafting of MAH onto PP performed in solution by means of ultrasonic initiation. The effect of sonic intensity and monomer concentration on the amount of grafted MAH was investigated. It was found that grafting reaction could be initiated by ultrasound at ambient temperatures in the absence of an initiator. The quantity of product grafted was found to be 1.35%. It has been shown that optimum conditions for grafting are reached at an ultrasonic intensity of 300 W and a MAH concentration of 30%. PP- g -MAH is characterized by FTIR and XRD. DSC shows that the crystallinity of PP- g -MAH is lower than that of pure PP. [source]

    Oxidation of Benzene to Maleic Anhydride in a Fluidized Bed Reactor

    C. Uraz
    Abstract In this project, the selective oxidation of benzene to maleic anhydride (MAN) was studied. Gas phase catalytic oxidation of benzene was carried out in a laboratory scale fluidized bed reactor on six different types of catalysts, which have different compositions. Effects of temperature, flow rates of benzene and air and catalyst type on the reaction selectivity were investigated at atmospheric pressure. The experiments were performed over a temperature range of 325 to 400,°C, a space-time (W/FA0) range from 11.28,×,105 to 31.9,×,105 g,s,mol,1, and benzene/air mole ratio changes between 0.0109 and 0.0477. It was seen that conversion of benzene to MAN increased with increasing temperature for the catalysts supported by silica gel, aluminum oxide and titanium oxide. From the results it was found that conversion increased with increasing flow rate of air. When the comparison of the catalysts were made, it could be said that catalysts supported by silica gel showed higher MAN conversions. So it can be concluded that catalysts supported by silica gel were more suitable catalysts for benzene oxidation to MAN in a fluidized bed reactor. [source]

    ChemInform Abstract: Synthesis of Novel 1,4-Benzoxazine-2,3-dicarboximides from Maleic Anhydride and Substituted Aromatic Amines.

    CHEMINFORM, Issue 25 2009
    Peng Wu
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: New Synthetic Approach to Epoxyisoindolo[2,1-a]quinolines Based on Cycloaddition Reactions of 2-Furyl-Substituted Tetrahydroquinolines with Maleic Anhydride and Acryloyl Chloride.

    CHEMINFORM, Issue 10 2008
    F. I. Zubkov
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Steric Effects in the Nucleophilic Addition of Pyrazoles Unsubstituted at a Nitrogen Atom to the Double Bond of Maleic Anhydride.

    CHEMINFORM, Issue 33 2004
    N. L. Nam
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    ChemInform Abstract: One-Step Synthesis of Complex Nitrogen Heterocycles from Imines and Alkyl-Substituted Maleic Anhydrides.

    CHEMINFORM, Issue 4 2010
    Yuchen Tang
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Preparation and characteristic of electric stimuli responsive hydrogel composed of polyvinyl alcohol/poly (sodium maleate- co -sodium acrylate)

    Yi Gao
    Abstract Maleic anhydride was used to preparare polyvinyl alcohol/poly (sodium maleate- co -sodium acrylate) hydrogels (PVA/poly(SMA-SAA)) by a repeated frost-defrost process because of its higher charge density and potential electric stimuli sensitivity. The bending angle was measured in a noncontact electric field using carbon as plate electrodes. It was found that the bending angle was dependent on various factors, including composition of hydrogel, concentration of NaCl solution, types of electrolyte solution, and electric voltage. It exhibited that the bending angle increased when the concentration of NaCl solutions and the electric voltages increased. An abnormal bending direction was observed, and it was affected not only by the kinds of hydrogels, but also by the exterior variations. The hydrogel showed good reversibility in on-off electric field and could be a candidate for practical application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

    Self-initiating performance of maleic anhydride on surface photografting polymerization

    Jian-Ping Deng
    Abstract Maleic anhydride (MAH) was photografted onto low-density polyethylene (LDPE) films with a grafting efficiency of about 70% in the absence of a photoinitiator. The self-initiating performance was attributed to a mechanism of abstracting hydrogen atoms from LDPE chains by excited MAH dimers. The supporting experimental results were as follows: (1) the far-UV radiation (200,300 nm) was indispensable for the graft polymerization and 2) the crosslinking reaction of LDPE inevitably accompanied the grafting of MAH. In addition, the initiation performance of MAH was further confirmed by surface photografting of acrylic acid in the presence of MAH, where MAH was used as the photoinitiator. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3246,3249, 2001 [source]

    Preparation and linear rheological behavior of polypropylene/MMT nanocomposites

    POLYMER COMPOSITES, Issue 3 2003
    Li Jian
    Maleic anhydride grafted low isotactic homopolypropylene elastomer (LiPP-g-MAH) is used as a compatibilizer in the melting mixing of polypropylene (PP) and clay. The microstructures of the composites of PP/clay (PPCN) are investigated using a wide-angle X-ray diffractometer (WAXD) and transmission electron microscope (TEM) as well as parallel rheometer, which show that PPCN with different phase morphologies have been obtained. It is found that the weight ratio of LiPP-g-MAH to clay and the weight content of LiPP-g-MAH in PPCN have a strong effect on the final dispersibility of the clay. The rheological response to small amplitude oscillatory shear (SAOS) shows that the storage modulus (G,) at the low frequencies is greatly sensitive to the microstructures in comparison with WAXD measurements. The investigation further indicates that the virgin clay particles, intercalated silicate crystallites, and exfoliated layers may coexist in the matrix at the same time, resulting in the great enhancement of G, plateau at low frequency region. [source]

    Effect of sawdust surface treatment and compatibilizer addition on mechanical behavior, morphology, and moisture uptake of polypropylene/sawdust composites

    Silvia H.P. Bettini
    Polypropylene/sawdust composites were investigated to assess the effect of sawdust surface treatment and compatibilizer addition on polymer/fiber adhesion. Two silane coupling agents were used for sawdust surface treatment: vinyl-tris (2-methoxyethoxy) silane and (3-aminopropyl)triethoxysilane. Maleic anhydride grafted polypropylene was used as compatibilizer. Composites were prepared in a corotating twin-screw extruder coupled to a Haake torque rheometer and submitted to tensile and bending tests as well as scanning electron microscopy (SEM). Moisture uptake tests were also performed. Results showed that incorporation of untreated sawdust to polypropylene (PP) caused reduction in composite tensile strength and increase in stiffness. When the only treatment used was surface modification with silane coupling agents, no significant changes were observed in mechanical properties. However, when compatibilizer was added to the composites, tensile strength was increased, and % elongation at break reduced, indicating improved system compatibility. The composite presenting the highest increase in tensile strength was that containing sawdust treated with amino silane in addition to the compatibilizer. SEM analyses corroborated the mechanical property results. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers [source]

    Mechanical and oxygen barrier properties of organoclay-polyethylene nanocomposite films

    Yang Zhong
    An organically modified montmorillonite was compounded with ethylene vinyl acetate copolymer (EVA), low density polyethylene (LDPE), and high density polyethylene (HDPE) in a twin-screw extruder. The resulting organoclay-polyethylene nanocomposites were then blown into films. Tensile properties and oxygen permeability of these nanocomposite films were investigated to understand the effects of organoclay on different types of polyethylene. It was found that the clay enhancing effects are function of the matrix. The mechanical and oxygen barrier properties of clay/EVA systems increased with clay loading. Both the tensile modulus and oxygen barrier of EVA doubled at 5 wt% clay. Maleic anhydride grafted polyethylene (MAPE) usually is used as a compatibilizer for LDPE and HDPE-based nanocomposites. However, the MAPEs were found to weaken the oxygen barrier of the PEs, especially for HDPE. This is believed to be a result of less compactness caused by the large side groups and the increase in polarity of the MAPEs. Incorporating 5 wt% clay improves the oxygen barrier by 30% and the tensile modulus by 37% for the LDPE/MAPE system. Incorporation of clay does not enhance the properties of the HDPE-based systems, likely due to large domain structure and poor bonding. Halpin,Tsai equation and the tortuous path equation were used to model the tensile modulus and oxygen permeability of the clay/EVA nanocomposite films. POLYM. ENG. SCI., 47:1101,1107, 2007. © 2007 Society of Plastics Engineers [source]

    Compatibilization of starch,polyester blends using reactive extrusion

    R.B. Maliger
    Maleic anhydride (MA) and dicumyl peroxide (DCP) were used as crosslinking agent and initiator respectively for blending starch and a biodegradable synthetic aliphatic polyester using reactive extrusion. Blends were characterized using dynamic mechanical and thermal analysis (DMTA). Optical micrographs of the blends revealed that in the optimized blend, starch was evenly dispersed in the polymer matrix. Optimized blends exhibited better tensile properties than the uncompatibilized blends. X-ray photoelectron spectroscopy supported the proposed structure for the starch,polyester complex. Variation in the compositions of crosslinking agent and initiator had an impact on the properties and color of the blends. POLYM. ENG. SCI. 46:248,263, 2006. © 2006 Society of Plastics Engineers [source]

    Kinetics and mechanism of the reaction between maleic anhydride and fatty acid esters and the structure of the products

    Florina Stefanoiu
    Abstract Alkenyl succinic anhydrides (ASA) were obtained by reaction between maleic anhydride and high-oleic sunflower oil (HOSO) esters. A kinetics study of the maleinization of alkyl esters indicated that the maleinization reaction was second order overall and first order with respect to the individual reactants, and the activation energy was 77.2,±,3.3,kJ/mol in the investigated temperature range (185,225,°C). These results showed that the cis configuration and the central position of the double bond in HOSO esters facilitate the maleinization of the latter. On the contrary, the length of the linear ester moiety had no influence on the course of the maleinization reaction. Moreover, new evidence demonstrates that there are two different reaction mechanisms: ene-reaction and addition in allylic position with a 2,:,1 ratio, respectively. This ratio was constant throughout the reaction, thus indicating that these mechanisms are independent. [source]

    The effect of polymers and surfactants on the pour point of palm oil methyl esters

    Cheah Han Sern
    Abstract The objective of this research was to find some additives suitable to reduce the pour point (PP) of palm oil methyl esters. The PP properties of palm oil methyl esters (biodiesel) were evaluated with commercially available polymeric and surfactant compounds with various polarities, molecular sizes and structures. The compounds under study were poly(ethylene glycol), poly(methyl methacrylate), poly(ethylene-co-vinyl acetate), poly(styrene-co-maleic anhydride), poly(ethylene glycol) distearate, poly-(octadecyl methacrylate), poly(1-decene), poly(maleic anhydride- alt -1-octadecene), caprylic acid sodium salt, N -lauroylsarcosine sodium salt, polyoxyethylene(2) cetyl ether and polyoxyethylene(10) cetyl ether. Seven out of the twelve polymeric compounds tested were miscible in palm oil methyl esters due to similar polarities of the solute and biodiesel. The blends of the resultant seven polymeric compounds in palm oil methyl esters were evaluated respectively for their effect on the PP property. Poly-(maleic anhydride- alt -1-octadecene) was able to improve the PP of palm oil methyl esters from 12 to 6,°C when 2,wt-% was added. The cloud point was reduced from 12.9 to 8.1,°C, and the cold filter plugging point was reduced from 12 to 7,°C, whilst the flash point value remained unchanged at 156,°C when 2,wt-% of poly(maleic anhydride- alt -1-octadecene) was added to the palm oil methyl esters. [source]

    Squaraine-Doped Functional Nanoprobes: Lipophilically Protected Near-Infrared Fluorescence for Bioimaging

    Yong-Deok Lee
    Abstract Hydrophobically stabilized near-IR fluorescence from self-assembled nanoprobes composed of amphiphilic poly(maleic anhydride- alt -octadec-1-ene) (PMAO) and lipophilized squaraine dopants is reported. From comparative studies with varying lipophilicity of squaraine dyes as well as of nanoparticulate polymer matrices, it is found that dual protection by simultaneous lipophilization of the dye-polymer pair greatly improves the chemical stability of labile squaraine dyes, to produce efficient NIR fluorescence in physiological aqueous milieux. The surface properties of negatively charged PMAO nanoparticles are readily modified by coating with an amine-rich cationic glycol chitosan with biofunctionality. Efficient cellular imaging and in vivo sentinel lymph node mapping with size and surface-controlled nanoprobes demonstrate that lipophilic dual protection of NIR fluorescence and the underlying functional nanoprobe approach hold great potential for bioimaging applications. [source]

    Chemoselective and Regiospecific Synthesis of Iminospiro- , -lactones from Maleic Anhydride or Citraconic Anhydride and Alkyl Isocyanides with Dialkyl Acetylenedicarboxylates

    Mohammad Bayat
    Abstract Isocyanides, dialkyl acetylenedicarboxylates (=dialkyl but-2-ynedioates), and anhydrides such as maleic anhydride (=furan-2,3-dione) or citraconic anhydride (=3-methylfuran-2,3-dione) react in one pot to afford novel iminospiro- , -lactones in fairly good yields at room temperature (Schemes,1 and 3). [source]

    Thiofenchone s -methylide and its spiro-1,3,4-thiadiazoline precursor

    Rolf Huisgen
    Spiro[fenchane-2,2,-(1,3,4)-thiadiazoline] (6), prepared from thiofenchone and diazomethane, extrudes N2 (t1/2 22 min, 46°C, toluene) and furnishes the S-methylide 7 which, in turn, closes the thiirane ring or else is intercepted by 1,3-cycloadditions to dipolarophiles (tetracyanoethylene, maleic anhydride, N-methyl-1,2,4-triazoline-3,5-dione, aromatic thioketones). When thiocarbonyl S-methylide 7 is set free in methanol, fenchone S,O-dimethylacetal is formed as an HX adduct. Catalysis by acetic acid converts 7 to 1-(methylthio)-,-fenchene (25) by way of a Wagner-Meerwein rearrangement. The addition of diazomethane to thiocampher leads, via thiadiazoline 12, to thiocamphor S-methylide; the latter undergoes a 1,4-H shift, thus affording 2-methylthio-2-bornene (11). © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:136,145, 2001 [source]

    Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversal

    N. K. Lohiya
    Summary The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F1 progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F1 progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO. [source]

    Comparison of polyamide 66,organoclay binary and ternary nanocomposites

    Miray Mert
    Abstract Polyamide 66,Lotader® 2210 blends (95/5 w/w), polyamide 66,Cloisite® 15A binary nanocomposites (98/2 w/w), and polyamide 66,Lotader® 2210,Cloisite® 15A ternary nanocomposites (93/5/2 w/w) were prepared by twin-screw extrusion, and the changes in mechanical properties, morphology, and flow properties of the materials prepared by different mixing sequences were investigated in this study. Lotader® 2210, which is a random terpolymer of ethylene, butyl acrylate, and maleic anhydride, was used as the impact modifier for polyamide 66 blends as well as polyamide 66 based nanocomposites. The best dispersion level, highest mechanical properties, highest viscosity values, and smallest elastomeric domain sizes were obtained for the mixing sequence in which all the components forming the ternary nanocomposites were compounded simultaneously. Incorporation sequence of either the organoclay or the impact modifier into the polymeric matrix was varied in the other mixing sequences, and this resulted in poorer distribution of the organoclay platelets and elastomeric domains in the matrix owing to insufficient shear intensity applied on the components in a single extrusion step. Toughness values of the ternary nanocomposites were improved compared with the binary nanocomposites upon addition of the impact modifier into polymer,organoclay combination. It was concluded that the compounding sequence of the components plays a significant role in the dispersion of organoclay and the properties of the nanocomposites, because it directly affects the interaction between the different phases. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:155,164, 2009; Published online in Wiley InterScience ( DOI 10.1002/adv.20158 [source]

    PP/EVA blends: Mechanical properties and morphology.

    Effect of compatibilizers on the impact behavior
    Abstract The mechanical properties of blends of isotactic polypropylene (PP) and poly[ethylene- co -(vinyl acetate)] (EVA) are studied under tension at several temperatures (from ,30°C to room temperature). The morphology and thermal properties are given attention at every stage of the stretching process. To improve the impact resistance of the blends, poly[propylene- graft -(maleic anhydride)] (PPMA) and hydroxylated EVA (EVAOH) are used as compatibilizers. The domain size of the dispersed phase decreases with compatibilizer content, improving the impact resistance of the blends. This is accompanied with changes in the morphology of such systems. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24: 241,252, 2005; Published online in Wiley InterScience ( DOI 10.1002/adv.20050 [source]

    Rubber toughening of glass fiber reinforced nylon-6,6 with functionalized block copolymer SEBS-g-MA

    George P. Karayannidis
    Abstract The toughening of glass fiber reinforced nylon-6,6 (PA-6,6) by using the functionalized triblock copolymer styrene-(ethylene-co-butylene)-styrene, grafted with maleic anhydride (SEBS-g-MA) was examined. Blends containing 2.5, 5, 7.5, 10, and 12.5 wt% copolymer were prepared by melt blending in a single-screw extruder. Emphasis was given to the study of mechanical properties in comparison with morphology and thermal properties of the aforementioned samples. Although the amount of SEBS-g-MA that was added in PA-6,6 was not enough to produce a super-tough material, a significant increase in the resistance to crack propagation and impact strength was observed in all blends. This behavior was proportional to the amount of SEBS-g-MA that was added for samples having up to 10%, rubber, while additional amounts seem to have no further effect. A small decrease in tensile strength was also observed. From FTIR spectroscopy and DSC analysis it was shown that the grafting extent of SEBS-g-MA to PA-6,6 was very low. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 153,163, 2002; Published online in Wiley Interscience ( DOI 10.1002/adv.10023 [source]

    Rheological, morphological, mechanical, and barrier properties of PP/EVOH blends

    Jong Ho Yeo
    Using the biaxially oriented film process, polypropylene (PP)/ethylene-vinyl alcohol copolymer (EVOH) blends with an improved barrier property could be obtained by generating a laminar structure of the dispersed phase in the matrix phase. This laminar morphology, induced by biaxial orientation, was found to result in a significant increase in the oxygen barrier property of PP/EVOH (85/15) blends by about 10 times relative to the pure PP. In this study, compatibility in the PP/EVOH blend system was evaluated by investigating the influence of compatibilizer on the rheological, morphological, and mechanical properties of the blends. In addition, the effects of compatibilizer content, draw ratio, and draw temperature on the oxygen permeability and morphology of biaxially drawn blend films were also studied. It was revealed that an optimum amount of compatibilizer, maleic anhydride grafted PP, should be used to improve the barrier property of the PP/EVOH blends with a well-developed laminar structure. The draw ratio and draw temperature had a significant influence on the permeability of the blends. The blend films exhibited a more pronounced laminar structure when the blends were stretched biaxially under processing conditions of higher draw ratio and draw temperature, resulting in higher barrier properties. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 191,201, 2001 [source]

    Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium-ion battery

    Xiaoyuan Yu
    Abstract The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium-ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the Tg and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10,3 S cm,1 at room temperature and 1.42 × 10,2 S cm,1 at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3O2 cell were evaluated at a current rate of 0.1C and in voltage range of 2.8,4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3 O2 cell is 115.3 mAh g,1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Crystallization and melting behavior of HDPE in HDPE/teak wood flour composites and their correlation with mechanical properties

    Kamini Sewda
    Abstract The nonisothermal crystallization behavior and melting characteristics of high-density polyethylene (HDPE) in HDPE/teak wood flour (TWF) composites have been studied by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) methods. Composite formulations of HDPE/TWF were prepared by varying the volume fraction (,f) of TWF (filler) from 0 to 0.32. Various crystallization parameters evaluated from the DSC exotherms were used to study the nonisothermal crystallization behavior. The melting temperature (Tm) and crystallization temperature (Tp) of the composites were slightly higher than those of the neat HDPE. The enthalpy of melting and crystallization (%) decrease with increase in the filler content. Because the nonpolar polymer HDPE and polar TWF are incompatible, to enhance the phase interaction maleic anhydride grafted HDPE (HDPE-g-MAH) was used as a coupling agent. A shift in the crystallization and melting peak temperatures toward the higher temperature side and broadening of the crystallization peak (increased crystallite size distribution) were observed whereas crystallinity of HDPE declines with increase in ,f in both DSC and WAXD. Linear correlations were obtained between crystallization parameters and tensile and impact strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Flocculated decolorization of vinylsulfone reactive dye solutions with a ,-cyclodextrin-based copolymer

    Xiuzhi Tian
    Abstract A ,-cyclodextrin (,-CD)-based copolymer (,-CD,maleic anhydride,N -trimethylaminoethylmethacrylate chloride) with good thermal stability was designed and synthesized for flocculated decolorization of Reactive Brilliant Blue KN-R solutions. Jar tests indicated that with the optimal stirring mode as 120 rpm for 5 min and then 40 rpm for 5 min with a flocculant-to-dye ratio of 2 : 5 (w/w), a pH of 8,10, and a temperature of 20°C, the maximum color removal reached. It is reported first in this article that, in addition to the polymer bridge and charge neutralization, the covalent bond of the reactive dye to the target flocculant molecules, which had a similar chemical structure to that of cellulose, contributed to the mechanism of flocculated decolorization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Flammability and mechanical properties of wood flour-filled polypropylene composites

    M. B. Abu Bakar
    Abstract Polypropylene (PP) composites filled with wood flour (WF) were prepared with a twin-screw extruder and an injection-molding machine. Three types of ecologically friendly flame retardants (FRs) based on ammonium polyphosphate were used to improve the FR properties of the composites. The flame retardancy of the PP/WF composites was characterized with thermogravimetric analysis (TGA), vertical burn testing (UL94-V), and limiting oxygen index (LOI) measurements. The TGA data showed that all three types of FRs could enhance the thermal stability of the PP/WF/FR systems at high temperatures and effectively increase the char residue formation. The FRs could effectively reduce the flammability of the PP/WF/FR composites by achieving V-0 UL94-V classification. The increased LOI also showed that the flammability of the PP/WF/FR composites was reduced with the addition of FRs. The mechanical property study revealed that, with the incorporation of FRs, the tensile strength and flexural strength were decreased, but the tensile and flexural moduli were increased in all cases. The presence of maleic anhydride grafted polypropylene (MAPP) resulted in an improvement of the filler,matrix bonding between the WF/intumescent FR and PP, and this consequently enhanced the overall mechanical properties of the composites. Morphological studies carried out with scanning electron microscopy revealed clear evidence that the adhesion at the interfacial region was enhanced with the addition of MAPP to the PP/WF/FR composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Polypropylene nanocomposite film: A critical evaluation on the effect of nanoclay on the mechanical, thermal, and morphological behavior

    S. K. Sharma
    Abstract Polypropylene (PP)/clay nanocomposites prepared by melt blending technique using different percentages of clay with and without maleic anhydride grafted PP (MA-PP) were studied. The intercalated and exfoliated structure of nanocomposites was characterized by X-Ray Diffraction (XRD) and transmission electron microscopy (TEM). Because of the typical intercalated and exfoliated structure, the tensile modulus of the nanocomposites were improved significantly as compared to virgin PP. The viscoelastic behavior of the nanocomposites was studied by dynamical mechanical analysis (DMA) and the results showed that with the addition of treated clay to PP there was substantial improvement in storage modulus increases. The thermal stability and crystallization of the PP nanocomposites as studied by differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) were also improved significantly compared to PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Study of PET/PP/TiO2 microfibrillar-structured composites, part 1: Preparation, morphology, and dynamic mechanical analysis of fibrillized blends

    Wenjing Li
    Abstract The objective of this study was to manufacture and investigate a novel microfibrillar-reinforced material based on fibrillized blends of polyethyleneterephthalate (PET), polypropylene (PP), and TiO2 nanoparticles (300 nm and 15 nm in size). The uncompatibilized and compatibilized blends (polypropylene grafted maleic anhydride as compatibilizer) were extruded and subsequently cold-drawn into strands with a draw ratio of 10. The effects of compatibilizer and TiO2 particles on the structure and properties of drawn strands were investigated. Upon addition of compatibilizer, the preferential location of TiO2 particles shifted from the PET-dispersed phase to the PP matrix, which brought about different structures of the drawn strands. Differential scanning calorimetry study provided indications for a heterogeneous nucleation effect of the PET fibrils on the PP matrix and of the TiO2 particles on the PET fibrils. Dynamic mechanical analysis demonstrated that the mechanical properties of the drawn strands are strongly dependent on the strand structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]