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  • Open Access

    ARTICLE

    A Study on the Effect of Reaction Parameters on Viscosity and Molecular Weight of Hexafluoropropylene (HFP) based Perfluoropolyethers (PFPEs)

    SAURABH SAXENAa, PRATEEK MALIKa, GEETHA SESHADRIa,*, AJAY K. TYAGIa, UTTAM KUMAR MANDALb

    Journal of Polymer Materials, Vol.36, No.1, pp. 39-51, 2019, DOI:10.32381/JPM.2019.36.01.4

    Abstract Medium molecular weight liquid perfluoropolyethers (840 u to 1372 u) were synthesized by photopolymerization of hexafluoropropylene (HFP) in the presence of oxygen. Effects of various reaction parameters such as temperature, pressure, UV wattage and reaction time on yield, viscosity and molecular weight of PFPEs were studied. Out of all the parameters, the effect of reaction temperature was found the most significant on molecular weight of PFPEs. By increasing reaction temperature, viscosity and molecular weight of PFPEs where decreased. By increasing the wattage of the lamp, viscosity and molecular weight of PFPEs where also decreased. PFPEs obtained from reactions were subjected… More >

  • Open Access

    ARTICLE

    Taguchi Design of the Experimental approach to Increase the Biomass and Cell Wall Chitosan Contents of Zygomycetous Dimorphic Fungus Benjaminiella Poitrasii

    S.R. MANE1,2, E. K. PATHAN3, G. PATIL4, S. G. TUPE5, V. GHORMADE4, B. P. CHAUDHARI1,2, M.V. DESHPANDE5,*

    Journal of Polymer Materials, Vol.38, No.3-4, pp. 219-230, 2021, DOI:10.32381/JPM.2021.38.3-4.4

    Abstract A dimorphic fungus Benjaminiella poitrasii contains high chitin/chitosan (35% of the cell wall) in the mycelial (M) form than its yeast (Y) form (20% of the cell wall). However, the relative proportion of chitosan is more in yeast form cells (chitosan: chitin ratio, 6:1) than mycelial cells (chitosan: chitin ratio, 3:1). Using the Taguchi design of experimental (DOE) approach, interactions among eight different parameters showed that carbon source (starch, 10 g/L), incubation time (48 h), inoculum (M and Y mixed 10%), yeast extract (6 g/L) and peptone (10 g/L), were optimum for maximum biomass production. Under these conditions, the chitosan… More >

  • Open Access

    ARTICLE

    Utilization of Bitter Orange Seed as a Novel Pectin Source: Compositional and Rheological Characterization

    Diako Khodaei1, Mohammad Nejatian2,*, Hassan Ahmadi Gavlighi2, Farhad Garavand3,*, Ilaria Cacciotti4

    Journal of Renewable Materials, Vol.10, No.11, pp. 2805-2817, 2022, DOI:10.32604/jrm.2022.021752

    Abstract The seeds from bitter orange, the by-product of juice making units, hold the potential to facilitate novel, easy yet high-quality pectin extraction. To test this hypothesis, orange seed pectin (OSP) was extracted by distilled water and its compositional parameters and rheological behavior were then evaluated. Results showed that galacturonic acid was the major component of OSP (∼425 mg/g) confirming the purity of the extracted pectin, followed by glucose and some minor neutral sugars. The Mw (weight-average molar mass), Rn (number average molar mass), and Rz (z-average molar mass) values for the OSP were 4511.8 kDa, 61 nm, and 61.1 nm,… More > Graphic Abstract

    Utilization of Bitter Orange Seed as a Novel Pectin Source: Compositional and Rheological Characterization

  • Open Access

    ARTICLE

    Improving Polylactide Toughness by Plasticizing with Low Molecular Weight Polylactide-Poly(Butylene Succinate) Copolymer

    Yottha Srithep1,*, Onpreeya Veang-in1, Dutchanee Pholharn2, Lih-Sheng Turng3, John Morris4

    Journal of Renewable Materials, Vol.9, No.7, pp. 1267-1281, 2021, DOI:10.32604/jrm.2021.015604

    Abstract A low-molecular-weight polylactide-poly(butylene succinate) (PLA-PBS) copolymer was synthesized and incorporated into polylactide (PLA) as a novel toughening agent by solvent casting. The copolymer had the same chemical structure and function as PLA and it was used as a plasticizer to PLA. The copolymer was blended with PLA at a weight ratio from 2 to 10 wt%. Phase separation between PLA and PLA-PBS was not observed from their scanning electron microscopy (SEM) images and the crystal structure of PLA almost remained unchanged based on the X-ray diffraction (XRD) measurement. The melt flow index (MFI) of the blends was higher as the… More >

  • Open Access

    ARTICLE

    Influence of the Molecular Weight on PVA/GO Composite Membranes for Fuel Cell Applications

    C. González-Guisasola1, O. Gil-Castell1,2, R. Teruel-Juanes1, A. Ribes-Greus1,*

    Journal of Renewable Materials, Vol.8, No.9, pp. 1171-1180, 2020, DOI:10.32604/jrm.2020.04399

    Abstract Composite polymer electrolyte membranes were prepared with poly (vinyl alcohol) (PVA). Two different molecular weight (Mw), 67·103 and 130·103 g·mol−1 were selected, cross-linked with sulfosuccinic acid (SSA) and doped graphene oxide (GO). The effects on the membranes obtained from these polymers were characterized in order to evaluate the fuel cell performance. Electron microscopy showed a proper nanoparticle distribution in the polymer matrix. The chemical structure was evaluated by Fourier transform infrared spectroscopy. The absence of a crystalline structure and the enhancement on the thermal stability with the addition of 1% of GO was demonstrated by thermal characterization. Total transference number… More >

  • Open Access

    ARTICLE

    Effect of Phenolation, Lignin-Type and Degree of Substitution on the Properties of Lignin-Modified Phenol-Formaldehyde Impregnation Resins: Molecular Weight Distribution, Wetting Behavior, Rheological Properties and Thermal Curing Profiles

    Marion Thébault1, Larysa Kutuzova2, Sandra Jury1, Iris Eicher1, Edith-Martha Zikulnig-Rusch1, Andreas Kandelbauer2,*

    Journal of Renewable Materials, Vol.8, No.6, pp. 603-630, 2020, DOI:10.32604/jrm.2020.09616

    Abstract Here, the effects of substituting portions of fossil-based phenol in phenol formaldehyde resin by renewable lignin from two different sources are investigated using a factorial screening experimental design. Among the resins consumed by the wood-based industry, phenolics are one of the most important types used for impregnation, coating or gluing purposes. They are prepared by condensing phenol with formaldehyde (PF). One major use of PF is as matrix polymer for decorative laminates in exterior cladding and wet-room applications. Important requirements for such PFs are favorable flow properties (low viscosity), rapid curing behavior (high reactivity) and sufficient self-adhesion capacity (high residual… More >

  • Open Access

    ARTICLE

    Low molecular weight heparin as an anticoagulation strategy for left-sided ablation procedures

    Karen Hinsley, Margaret Evans-Langhorst, Courtney Porter, Stephanie Chandler, Christina VanderPluym, John Triedman, Vassilios J. Bezzerides

    Congenital Heart Disease, Vol.13, No.2, pp. 222-225, 2018, DOI:10.1111/chd.12551

    Abstract Objective: This quality improvement study was implemented to demonstrate consistent and reliable post procedure anticoagulation for patients undergoing left-sided ablations. We evaluated the safety and efficacy of anticoagulation practice during a transition from anticoagulation with overnight infusion of unfractionated heparin to a single subcutaneous injection of low molecular weight heparin.
    Methods: Outcomes for patients who received unfractionated heparin from January 2014 to October 2014, were compared with outcomes of patients who received low molecular weight heparin from October 2014 to October 2015. Complications prepractice and postpractice change were documented and compared to establish confidence in the practice change and confirm… More >

  • Open Access

    ARTICLE

    Structural Characterization and Antioxidant Activity of Lignin Extracted from Ficus Carica L.

    Ibtissem Moussa1,2, Ramzi Khiari1,3,4,*, Ali Moussa2, Gérard Mortha4, Mohamed Farouk Mhenni1

    Journal of Renewable Materials, Vol.7, No.4, pp. 345-354, 2019, DOI:10.32604/jrm.2019.04011

    Abstract The most abundant phenolic biopolymer in the biosphere is the lignin. This phenolic biopolymer commonly exists in combination with polysaccharides and other cell wall components. In this study, the solvent system dioxane-water is used to extract lignin, which is considered as unaltered native lignin. The dioxane lignin extracted from fig stems was characterized regarding to its structural feature, quantification of its functional groups, molecular weight, and evaluation of its thermal properties. Purity and molecular weight distribution of the studied lignin indicated that isolated lignin contained a low amount of sugar (c.a. 19%) and had a high weight-average molecular weight (10… More >

  • Open Access

    ARTICLE

    The Effects of Gamma Irradiation on Molecular Weight, Morphology and Physical Properties of PHBV/Cloisite 30B Bionanocomposites

    Kahina Iggui1,2,*, Mustapha Kaci1, Mohamed Mahlous3, Nicolas Le Moigne4, Anne Bergeret4

    Journal of Renewable Materials, Vol.7, No.9, pp. 807-820, 2019, DOI:10.32604/jrm.2019.06778

    Abstract In this paper, the effects of gamma irradiation on Cast poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV/Cloisite 30B (C30B) (3 wt%) bionanocomposite prepared by melt compounding, were evaluated at various doses, i.e., 5, 15, 20, 50 and 100 kGy at room temperature in air. Changes in molecular weight, morphology and physical properties were investigated. The study showed that the main degradation mechanism occurring in gamma irradiation in both Cast PHBV and C-PHBV/3C30B bionanocomposite is chain scission, responsible for the decrease of molecular weight. Differential scanning calorimetry (DSC) data indicated a regular decrease in crystallization temperature, melting temperature and crystallinity index for all irradiated… More >

  • Open Access

    ARTICLE

    The Effects of Accelerated Photooxidation on Molecular Weight and Thermal and Mechanical Properties of PHBV/Cloisite 30B Bionanocomposites

    Kahina Iggui1,2,*,†, Mustapha Kaci2, Nicolas Le Moigne1, Anne Bergeret1

    Journal of Renewable Materials, Vol.6, No.3, pp. 288-298, 2018, DOI:10.7569/JRM.2017.634184

    Abstract The effects of accelerated photooxidation on the molecular weight and thermal and mechanical properties of Cast PHBV and PHBV/Cloisite 30B (3 wt%) bionanocomposites are investigated herein. Through size exclusion chromatography (SEC) analysis, a significant decrease in both weight and number average molecular weights was observed for all irradiated samples over time, resulting from the chain scission mechanism. Differential scanning calorimetry (DSC) data indicated a decrease in degree of crystallinity and melting temperature after UV exposure, with the appearance of double melting peaks related to the changes in the crystal structure of PHBV. Thermal stability, tensile and thermo-mechanical properties were also… More >

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