scholarly journals The Chemical Compatibility and Adhesion of Energetic Materials with Several Polymers and Binders: An Experimental Study

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1396 ◽  
Author(s):  
Trung Nguyen ◽  
Duc Phan ◽  
Duy Nguyen ◽  
Van Do ◽  
Long Bach
Keyword(s):  
Energetic Materials ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Work Of Adhesion ◽  
Chemical Compatibility ◽  
Scanning Calorimetry ◽  
And Performance ◽  
Stanag 4147 ◽  
Vacuum Stability Test ◽  
Interfacial Characteristics

The chemical compatibility and the adhesion of energetic materials and additive materials exert a strong influence on the sensitivity, safety and performance of a polymer-bonded explosive (PBX). In this study, the chemical compatibility of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), pentaerythritol tetranitrate (PETN) with several polymers were evaluated using the vacuum stability test (VST) and the differential scanning calorimetry (DSC); while the adhesion between RDX or PETN and each binder based on these polymers was determined through interfacial characteristics using contact angle measurement. The experimental results demonstrate that RDX and PETN are compatible with polystyrene (PS), nitrocellulose (NC) and fluoroelastomer (FKM) according to the STANAG 4147. Therefore the two polymers can be used as adhesives in PBX composition. Moreover, based on interfacial characteristics such as interfacial tension and work of adhesion, the adhesion between RDX and each binder was predicted to be better than that of PETN.

Polyamide grafting onto ethylene-vinyl alcohol copolymer

2013 ◽  
Vol 33 (9) ◽  
pp. 843-850 ◽  
Author(s):  
Hamid Salehi-Mobarakeh ◽  
Ali Yadegari ◽  
Javad Didehvar ◽  
Fahimeh Khakzad-Esfahlan
Keyword(s):  
Vinyl Alcohol ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Attenuated Total Reflection ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Melt Temperature ◽  
Ethylene Vinyl Alcohol ◽  
Chemically Modified ◽  
Bond Stretching

Abstract Ethylene-vinyl alcohol copolymers (EVOH), with appropriate barriers and processability, can be chemically modified through vinyl alcohol units. Amides and polyamides based on condensation reactions of adipoyl chloride and hexamethylenediamine were grafted onto EVOH. Grafting was characterized by contact angle measurement, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), nuclear magnetic resonance spectroscopy (NMR) and scanning electron microscopy (SEM). Amide peaks at 3302 cm-1 corresponding to –NH bond stretching and the absorption of HN-CH2 at 7.8 ppm, were observed from ATR-FTIR and NMR, respectively, as a result of grafting. SEM showed the formation of amide structures as bundles, agglomerates and needle-like particles. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) showed considerable changes in onset of melt temperature, crystallinity and various transitions in grafted EVOH, showing an effective alteration in the physical properties compared with the virgin resin. Nylon grafted EVOH can be considered as a potential compatibilizer in polyethylene (PE)/polyamide blends via increasing interactions at the interface.

Ionic conductive nanocomposite based on poly(l-lactic acid)/poly(amidoamine) dendrimerelectrospun nanofibrous for biomedical application

2021 ◽  
Author(s):  
Paniz Memarian ◽  
Atefeh Solouk ◽  
Zohre Bagher ◽  
Somaye Akbari ◽  
Masoumeh Haghbin Nazarpak
Keyword(s):  
Lactic Acid ◽  
Ionic Conductivity ◽  
Cell Viability ◽  
Biomedical Application ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Scanning Calorimetry ◽  
Cell Viability Assay ◽  
Viability Assay

Abstract The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal stem cell viability. It is worth mentioning that this is the first report investigating the conductivity of PLLA/PAMAM nanofiber. The results revealed that by increasing the amount of PAMAM, the ionic conductivity of scaffolds was enhanced by about nine times. Moreover, the outcomes indicated that the presence of PAMAM could improve the limitations of PLLA like hydrophobicity, lack of active group, and poor cell adhesion.

Study on Surface Modification of Polyethylene Terephthalate(PET) Film by RF-Ar/O2 Plasma Treatment

2012 ◽  
Vol 200 ◽  
pp. 194-198 ◽  
Author(s):  
Lin Kun Xie ◽  
Qin Ling Dai ◽  
Guan Ben Du ◽  
Qi Ping Deng ◽  
Gang Lian Liu
Keyword(s):  
Polyethylene Terephthalate ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Glow Discharge Plasma ◽  
Scanning Calorimetry ◽  
Static Contact ◽  
Before And After ◽  
Pet Film

The surface of polyethylene terephthalate film was modified using RF- Ar/ O2 glow discharge plasma under the condition of Ar and O2 flow amount of 1.9 and 1.2 (L/min) respectively and treatment power of 60 W. The changes of the properties of the film before and after modification were analyzed and characterized with static contact angle measurement, X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), differential scanning calorimetry(DSC). The results showed that the hydrophile of PET film was improved obviously after modification and formed some polar groups such as C-N, N-C=O, C=O, etc. on the film surface; The surface roughness was increased and appeared conical or globular protuberances; the thermal behaviors (mainly crystallinity) were changed after treatment by RF- Ar/O2 plasma.

scholarly journals Compatibility Study of 1,1-Diamino-2,2-Dinitroethene (FOX-7) with Some Energetic Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yuan-ping Zhang ◽  
Cong-hua Hou ◽  
Xin-lei Jia ◽  
Ying-xin Tan ◽  
Jing-yu Wang
Keyword(s):  
Energetic Materials ◽  
High Performance ◽  
Binary Systems ◽  
Compatibility Study ◽  
Scanning Calorimetry ◽  
Vacuum Stability ◽  
Dsc Measurements ◽  
Vacuum Stability Test ◽  
Low Sensitivity ◽  
Thermal Technique

1,1-diamino-2,2-dinitroethene (FOX-7) is a novel explosive with low sensitivity and high performance. The compatibility of FOX-7 with nine common energetic materials including hexanitrohexazaisowurtzitane (CL-20), cyclotetramethylenetetranitramine (HMX), cyclotrimethylenetrinitramine (RDX), 3,4-dinitrofurazanfuroxan (DNTF), 3-nitro-1,2,4-triazol-5-one (NTO), hexanitrostilbene (HNS-II), 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), 2,4,6-triamino-1,3,5-trinitrobenzene (TATB), and 2,4,6-trinitrotoluene (TNT) were tested by differential scanning calorimetry (DSC) and the vacuum stability test (VST) as the thermal technique and X-ray diffractometry (XRD) as a nonthermal technique. DSC measurements showed that the binary systems of FOX-7/CL-20, FOX-7/HMX, FOX-7/NTO, and FOX-7/TNT were compatible in grade of A, the systems of FOX-7 with heat-resistant explosives including HNS-II, LLM-105, and TATB were compatible as well in grade of A-B, and the binary systems of FOX-7/DNTF and FOX-7/RDX had poor compatibility. VST results indicated that FOX-7 was compatible with nine energetic materials. Besides, the compatibility results of the thermal analysis were confirmed by the XRD technique.

Structure and properties of polytetrafluoroethylene (PTFE) fibers

e-Polymers ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 215-220 ◽  
Author(s):  
Ruiliu Wang ◽  
Guangbiao Xu ◽  
Yuechao He
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Cross Sections ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Excellent Thermal Stability ◽  
Ft Ir

AbstractStructure and properties of polytetrafluoroethylene (PTFE) fibers were characterized thoroughly by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analyzing (TG) and water contact angle measurement. It was found that the longitudinal surface of the fiber was not smooth and was full of grooves. The cross sections of fibers were sheet-like and irregular. The infrared spectrum of PTFE fibers was the same as that of PTFE films except the 626 cm-l bands which were associated with the helix-reversal defect. The range of fineness distribution (2.09–11.50 dtex) was wide and the average strength was 1.37 cN/dtex. PTFE fibers began to be decomposed at 508.6°C and showed excellent thermal stability. The water contact angle of fibers layers was 120° indicating it to be a hydrophobic material. All these results provide a theoretical foundation for applications of PTFE fibers.

MODIFICATION OF SKIM RUBBER BLENDED WITH POLY (VINYL ALCOHOL) TO BE APPLIED AS A BIODEGRADABLE PRESSURE-SENSITIVE ADHESIVE: EFFECT OF 2,6-DI-T-BUTYL-4-METHYLPHENOL AND HYDROCARBON RESIN

2012 ◽  
Vol 85 (4) ◽  
pp. 547-558 ◽  
Author(s):  
Sa-Ad Riyajan ◽  
Nataphon Pheweaw
Keyword(s):  
Vinyl Alcohol ◽  
Chain Scission ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Poly Vinyl Alcohol ◽  
Pressure Sensitive Adhesive ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Pressure Sensitive ◽  
Adhesive Effect

ABSTRACT Pressure-sensitive adhesives (PSAs), or self-adhesives, are used in many applications, including safety labels for power equipment, automotive interior trim assembly, and sound/vibration–damping films. The objective of this study was to develop a biodegradable skim rubber–based bioadhesive blended with poly (vinyl alcohol) (PVA), which has the advantage of being biodegradable and biocompatible to humans. PSAs were produced from saponified low-protein skim rubber (S-LPSR) alone using a hydrocarbon resin as a tackifier and blends of S-LPSR/PVA containing tackifier, via solution and emulsion, respectively. The influence of 2,6-di-t-butyl-4-methylphenol (BHT) and the hydrocarbon resin content in the adhesive formulation was studied. Various methods were used to evaluate the properties of the adhesives produced including scanning electron microscopy, differential scanning calorimetry, contact angle measurement, dynamic mechanical thermal analysis, and Fourier transform infrared spectroscopy. The optimal concentration of PVA for a good PSA was found to be 20 phr because of its emulsion form. The adhesion properties of a PSA containing 50–60 phr of hydrocarbon resin and 1% BHT displayed excellent tack and peel compared with other samples because there was no chain scission of the skim rubber and good compatibility and interaction between the S-LPSR/PVA blend and the hydrocarbon resin, which maximized the adhesion properties of the adhesive.

Preparation and characterization of novel VAc/VeoVa10/DBM/VTES quadripolymer latex emulsified with green surfactants

2019 ◽  
Vol 35 (4) ◽  
pp. 188-197
Author(s):  
Lijun Chen ◽  
Tantan Shao ◽  
Yilu Gong ◽  
Xiuming Wang
Keyword(s):  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Chemical Compositions ◽  
The Novel ◽  
Mass Ratio ◽  
Seeded Emulsion Polymerization ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Vinyl Silane ◽  
Dibutyl Maleate

The novel vinyl acetate (VAc)/vinyl neo-decanoate (VeoVa10)/dibutyl maleate/triethoxy vinyl silane quadripolymer latex was prepared via the semi-continuous seeded emulsion polymerization emulsified with disodium laureth sulfosuccinate (AEMES) as anionic surfactant and beta-cyclodextrin (β-CD) mixture as emulsifier and initiated with potassium persulfate (KPS), respectively. The chemical compositions of copolymer was determined by Fourier transform infrared spectromer (FTIR). The glass transition temperature ( Tg) of the copolymer was measured by differential scanning calorimetry. The water resistance of the film was assessed by the water contact angle measurement. The conditions of preparing the novel latex were optimized and obtained as follows. The amount of AEMES and β-CD mixtures were 6 wt% and the mass ratio of AEMES to β-CD were 1:1. The dosage of KPS was 0.6 wt% and the mass ratio of VAc to VeoVa10 was 3:1. The amount of dibutyl maleate and triethoxy vinyl silane was 4% and 3%, respectively. In this case, the conversion percentage of the mixed monomers was 99.0% and the polymerization stability was good.

scholarly journals Selective Separation of 1-Butanol from Aqueous Solution through Pervaporation Using PTSMP-Silica Nano Hybrid Membrane

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 55 ◽  
Author(s):  
VSSL Prasad Talluri ◽  
Aiym Tleuova ◽  
Seyedmehdi Hosseini ◽  
Ondrej Vopicka
Keyword(s):  
Contact Angle ◽  
Surface Hydrophobicity ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Sem Analysis ◽  
Mixed Matrix Membrane ◽  
Hexadecyltrimethylammonium Bromide ◽  
Scanning Calorimetry ◽  
Angle Measurements ◽  
Surface Modified

In this work, a poly(1-trimethylsilyl-1-propyne) (PTMSP) mixed-matrix membrane was fabricated for the selective removal of 1-butanol from aqueous solutions through pervaporation. Silica nanoparticles (SNPs), which were surface-modified with surfactant hexadecyltrimethylammonium bromide (CTAB), were incorporated into the structure of the membrane. The modified membrane was characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), contact angle measurements, and scanning electron microscope (SEM) analysis. It was found that the surface hydrophobicity of the membrane was improved when compared to neat PTMSP by contact angle measurement. It was confirmed by SEM analysis that a uniform distribution of surface-modified SNPs throughout the PTMSP membrane was achieved. The thermogravimetric analysis detected the thermal degradation of the modified PTMSP at 370 °C, which is comparable to neat PTMSP. The pervaporation measurements showed a maximum separation factor of 126 at 63 °C for 1.5 w/w% 1-butanol in the feed. The maximum total flux of approximately 1.74 mg·cm−2·min−1 was observed with the highest inspected temperature of 63 °C and at the 1-butanol concentration in the feed 4.5 w/w%. The pervaporation transients showed that the addition of the surface-modified SNPs significantly enhanced the diffusivity of 1-butanol in the composite compared to the neat PTMSP membrane. This improvement was attributed to the influence of the well-dispersed SNPs in the PTMSP matrix, which introduced an additional path for diffusivity.

scholarly journals Characterization of fabrics coated with doped TiO 2 -graphene

2020 ◽  
Vol 71 (02) ◽  
pp. 156-162
Author(s):  
Iuliana Dumitrescu ◽  
OVIDIU-GEORGE IORDACHE ◽  
ELENA-CORNELIA MITRAN ◽  
ELENA PERDUM ◽  
IRINA-MARIANA SĂNDULACHE ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Cotton Fabric ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Woven Fabrics ◽  
Visible Range ◽  
Material Surface ◽  
Scanning Calorimetry ◽  
Fluorocarbon Polymer

This study presents the results of laboratory experiments to prepare cotton woven fabrics with photoactive properties. The fabric was treated with TiO 2 – Fe(1%) – N + 2% graphene by exhaustion followed by a fluorocarbon polymer treatment. The fabric was analyzed by Scanning Electron Microscope coupled with Energy Dispersive Spectroscopy (SEM/EDAX), Differential scanning calorimetry (DSC), Contact Angle measurement, physical properties (weight, thickness, breaking strength, elongation, air/water permeability, electrical resistance). The photocatalytic activity was determined initially and after 5 washings by measuring the trichromatic coordinates of the treated fabrics stained with methylene blue and exposed to UV and visible light on a Hunterlab UV-Vis spectrophotometer. The results demonstrate a uniform deposition of doped TiO 2 -graphene particles on material surface. The thermal stability of the coated cotton fabric is practically unmodified in comparison with blank cotton fabric. The decrease of the surface resistivity demonstrates the deposition of graphene layer, known for its good electrical conductivity. The wetting capacity of initial hydrophilic cotton fabric is dramatically modified, the fabric becoming hydrophobic after treatment. The photocatalytic efficiency is higher under visible light than under UV-radiation due to the TiO 2 doping and decoration with graphene, which extend the light absorption from UV to visible range. The good photocatalytic activity under visible light is maintained after 5 washing cycles.

Stimuli-Responsive Films Based on N-Substituted Polyurethane with Different Alkyl Length

2013 ◽  
Vol 66 (11) ◽  
pp. 1361 ◽  
Author(s):  
Yanyan Wang ◽  
Libin Liu ◽  
Congde Qiao ◽  
Tianduo Li
Keyword(s):  
Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Remarkable Change ◽  
Water Contact ◽  
Force Microscopy ◽  
Poly Propylene ◽  
Chain Lengths

N-Alkyl-substituted polyurethanes with different alkyl chain lengths were prepared from the corresponding bromoalkane (1-bromooctane, 1-bromotetradecane, and 1-bromooctadecane) and polyurethane consisting of poly(propylene glycol) (PPG), 4,4′-diphenylmethane diisocyanate, and 1,4-butanediol. The synthesised materials were characterised by 1H NMR and FTIR spectroscopy and the degrees of substitution were discussed by changing the reaction conditions. Differential scanning calorimetry and X-ray diffraction were used to characterise the thermal properties and crystalline state. Microphase-separated nanostructures, with hard segments (nanofibre-like) embedded into amorphous PPG soft segments, are observed by atomic force microscopy and scanning electron microscopy. A reversible behaviour of the films was revealed by contact angle measurement. Stimuli-responsive films were realised by solvent vapour annealing and heat treatment, and exhibited a reversible switching in surface wettability with a remarkable change in the water contact angle of 21°.

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