scholarly journals Synthesis and Properties of Moisture-Cured Reactive Polyurethane Containing Castor Oil and Oxime Compounds

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1838
Author(s):  
Zheng-Ying Wu
Keyword(s):  
Mechanical Properties ◽  
Castor Oil ◽  
Random Distribution ◽  
Crosslinking Density ◽  
Ftir Analysis ◽  
Dynamic Mechanical Analyzer ◽  
Two Stage ◽  
Characteristic Absorption Peak ◽  
Stage Synthesis ◽  
Hot Melt

Reactive polyurethane hot-melt resin (moisture-cured reactive polyurethane, PUR) could successfully be prepared from poly(tetramethylene ether) glycol (PTMG), castor oil and dimethylglyoxime (DMG) by one or two-stage synthesis. Fourier-transform infrared spectroscopy (FTIR) analysis showed that the synthesis resins belonged to NCO-capped castor oil-based polyurethane. The thermal behaviors of the cured PUR were analyzed by differential scanning calorimeter (DSC) and dynamic mechanical analyzer (DMA) instruments. The results showed that the cured resin provided remeltable properties under the dosages of 3 wt% DMG. Furthermore, the phenomenon could be proved by FTIR analysis according to the characteristic absorption peak of NCO groups after the cured resin was heated. Comparing different syntheses, the resin prepared by one-stage synthesis showed random distribution of DMG with PUR structure and that prepared by two-stage synthesis had distribution of DMG with branching structure in the prepolymer. The former obtained lower remeltable temperatures from 90 to 130 °C than the latter temperatures, which had temperatures above 125 °C. The tensile test showed that all of the PUR films exhibited typical tough behavior. Thus, the cured resin with DMG dosages of 3 wt% provided remeltable and mechanical properties at the same time. Overall, the crosslinking density and numbers of dynamic bonds should be kept in balance for preparation of remeltable PUR.

scholarly journals Effects of Various Types of Expandable Graphite and Blackcurrant Pomace on the Properties of Viscoelastic Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Ftir Analysis ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Physical And Chemical ◽  
Scanning Electron

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.

Temperature-programmed nitridation of monodispersed VOx nanoparticles into nanocrystalline superconducting oxygen-doped vanadium nitride

2021 ◽  
Author(s):  
Khemchand Dewangan ◽  
Dadan Singh ◽  
Sandeep Kumar Singh Patel ◽  
Kamlesh Kumar Shrivas
Keyword(s):  
Thermal Decomposition ◽  
Synthesis Process ◽  
Vanadium Nitride ◽  
High Quality ◽  
Two Stage ◽  
Stage Synthesis ◽  
Temperature Programmed ◽  
Superconducting Applications

A two-stage synthesis process was employed to prepare high-quality nanocrystalline vanadium nitride (VN) for superconducting applications. Firstly, monodispersed amorphous VOx nanoparticles were obtained via thermal-decomposition of vanadium (III) acetylacetonate [V(acac)3]...

Effect of Castor Oil Impregnation on the Physical and Mechanical Properties of Bacterial Cellulose

2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Young’S Modulus ◽  
Castor Oil ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Scanning Electron Micrographs ◽  
Elongation At Break ◽  
Acetone Water

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.

Castor Oil Based Polyurethane Nanocomposites with Cellulose Nanocrystallites Fillers

2013 ◽  
Vol 856 ◽  
pp. 309-313 ◽  
Author(s):  
Anupama Kaushik ◽  
Alka Garg
Keyword(s):  
Mechanical Properties ◽  
Castor Oil ◽  
Barrier Properties ◽  
Filler Loading ◽  
Total Weight ◽  
High Shear ◽  
Homogeneous Dispersion ◽  
Cotton Linters ◽  
Polyurethane Nanocomposites ◽  
Polyurethane Matrix

In this study the castor oil based polyurethane (PU) nanocomposites were prepared by dispersing the cellulose nanocrystallites (CNC) isolated from cotton linters. CNC was dispersed in PU matrix using ultrasonicator coupled with high shear homogenizer. The filler loading was varied from 0-10% of the total weight of the mixture. The PU/CNC nanocomposites were characterized by SEM, XRD, FTIR, mechanical and barrier properties. SEM confirmed homogeneous dispersion of CNCs in polyurethane matrix with small agglomerates at certain places. Improvement in mechanical properties was observed as compared to neat PU. Diffusivity and permeability of the nanocomposites was reduced at higher loadings of CNC.

EFFECTS OF STOICHIOMETRY ON PROPERTIES OF DGEBF/DETDA EPOXY USING MOLECULAR DYNAMICS

2021 ◽  
Author(s):  
SAGAR PATIL ◽  
MICHAEL OLAYA ◽  
PRATHAMESH DESHPANDE ◽  
MARIANNA MAIARÙ ◽  
GREGORY ODEGARD
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Modeling ◽  
Bulk Modulus ◽  
Mass Density ◽  
Strong Dependence ◽  
Crosslinking Density ◽  
Mechanical Deformation ◽  
Epoxy System ◽  
Reactive Interface

This article details the molecular modeling of full and off-stoichiometry models of the DGEBF/DETDA epoxy system using Molecular Dynamics to predict the mechanical properties as a function of the crosslinking density. The Reactive Interface Force Field (IFF-R) is implemented in this work to simulate mechanical deformation. The “fix bond/react” command in LAMMPS is used to simulate crosslinking between epoxy monomers. The results show that the predicted mass density, volumetric shrinkage, and bulk modulus have a strong dependence on the stoichiometry of the epoxy.

Effect of CePO4 nanostructures in transparent PMMA/castor-oil based PU IPNs on thermal stability, optical and mechanical properties

2017 ◽  
Vol 24 (9) ◽  
Author(s):  
D. Palma-Ramírez ◽  
M. A. Domínguez-Crespo ◽  
A. M. Torres-Huerta ◽  
H. Dorantes-Rosales ◽  
J. A. Andraca-Adame ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Castor Oil ◽  
Optical And Mechanical Properties

Microstructure and mechanical properties of two-stage aged Al–Cu–Mg–Ag–Sm alloy

Rare Metals ◽  
2018 ◽  
Vol 38 (1) ◽  
pp. 42-51 ◽  
Author(s):  
Wen-Long Zhang ◽  
Dai-Hong Xiao ◽  
Ting Li ◽  
Jian-Di Du ◽  
Dong-Yan Ding
Keyword(s):  
Mechanical Properties ◽  
Two Stage ◽  
Microstructure And Mechanical Properties

scholarly journals Влияние содержания корунда и температуры спекания на механические свойства керамических композитов CaO-ZrO-=SUB=-2-=/SUB=--Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

2018 ◽  
Vol 44 (4) ◽  
pp. 25 ◽  
Author(s):  
А.А. Дмитриевский ◽  
А.И. Тюрин ◽  
А.О. Жигачев ◽  
Д.Г. Гусева ◽  
П.Н Овчинников
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Mechanical Characteristics ◽  
Vickers Microhardness ◽  
Ceramic Composites ◽  
Optimum Regime ◽  
Two Stage

AbstractWe have studied the mechanical properties (Vickers microhardness H _V and fracture toughness K _C) of nanostructured CaO–ZrO_2–Al_2O_3 ceramic composites as dependent on the content of corundum (0 ≤ $$C_{Al_{2}O_{3}}$$ C A l 2 O 3 ≤ 25%) and the temperature of sintering (1250°C ≤ T _1 ≤ 1500°C). Optimum value of the corundum content ( $$C_{Al_{2}O_{3}}$$ C A l 2 O 3 = 5%) and optimum regime ( T _1 = 1300°C, 5 min; T _2 = 1200°C, 4 h) of two-stage sintering are established, which favor attaining the best mechanical characteristics of ceramic composites ( H _V = 12.25 GPa, K _C = 8.47 MPa m^1/2).

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