scholarly journals Morphologic and Chemical Properties of PMMA/ATH Layers with Enhanced Abrasion Resistance Realised by Cold Plasma Spraying at Atmospheric Pressure

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
L. Wallenhorst ◽  
R. Rerich ◽  
M. Vovk ◽  
S. Dahle ◽  
H. Militz ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Abrasion Resistance ◽  
Cold Plasma ◽  
Phenol Formaldehyde ◽  
Chemical Properties ◽  
Formaldehyde Resin ◽  
Hydroxyl Groups ◽  
Properties Of Coatings ◽  
Process Gas ◽  
And Chemical Properties

This study investigated the morphologic and chemical properties of coatings based on PMMA/ATH powder and deposited by cold plasma spraying on wood and glass. Since the deposition of pure PMMA/ATH powder with air as process gas yielded coatings with insufficient abrasion resistance, two modifications of the basic process were investigated. Previous studies showed that replacing air as process gas with forming gas did not enhance the abrasion resistance, but the addition of a phenol-formaldehyde resin (PF) succeeded in stabilising the particle coatings. In this work, results from morphologic and chemical analysis suggested an encasement of the PMMA/ATH particles by plasma-modified PF and thus a fusion of individual particles, explaining the enhanced bonding. Moreover, adhesion tests confirmed an outstanding bonding between the coating and wood as well as glass, which is assumed to result from interactions between the PF’s hydroxyl groups and functional groups on the substrates’ surfaces. Studies on the wettability revealed a hydrophobic character of such coatings, therefore generally indicating a possible application, for example, to reduce water uptake by wooden materials.

scholarly journals Microwave Assisted Synthesis of Phenol-Formaldehyde Resole

2007 ◽  
Vol 4 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Subhash Chandra Bajia ◽  
Pawan Swarnkar ◽  
Sudesh Kumar ◽  
Birbal Bajia
Keyword(s):  
Phenol Formaldehyde ◽  
Chemical Properties ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Microwave Assisted Synthesis ◽  
Physical And Chemical Properties ◽  
Efficient Synthesis ◽  
Microwave Assisted ◽  
Physical And Chemical ◽  
And Chemical Properties

An efficient synthesis of phenol-formaldehyde resin has been achieved by using conventional as well as microwave irradiation. Resin samples were tested for their physical and chemical properties. The structures of the resins have been supported by their spectral analysis.

scholarly journals Potential of Biochar Derived from Agricultural Residues for Sustainable Management

2021 ◽  
Vol 13 (15) ◽  
pp. 8147
Author(s):  
Sasiwimol Khawkomol ◽  
Rattikan Neamchan ◽  
Thunchanok Thongsamer ◽  
Soydoa Vinitnantharat ◽  
Boonma Panpradit ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Agricultural Residues ◽  
Hydroxyl Groups ◽  
Asian Countries ◽  
Heating Value ◽  
Coconut Husk ◽  
High Heating Value ◽  
Horizontal Drum ◽  
Physical And Chemical ◽  
And Chemical Properties

A horizontal drum kiln is a traditional method widely used in Southeast Asian countries for producing biochar. An understanding of temperature conditions in the kiln and its influence on biochar properties is crucial for identifying suitable biochar applications. In this study, four agricultural residues (corncob, coconut husk, coconut shell, and rice straw) were used for drum kiln biochar production. The agricultural residues were turned into biochar within 100–200 min, depending on their structures. The suitability of biochar for briquette fuels was analyzed using proximate, ultimate, and elemental analysis. The biochar’s physical and chemical properties were characterized via bulk density, iodine number, pHpzc, SEM, and FTIR measurements. All biochars had low O/C and H/C ratios and negative charge from both carbonyl and hydroxyl groups. Coconut husk and shell biochar had desirable properties such as high heating value and a high amount of surface functional groups which can interact with nutrients in soil. These biochars are thus suitable for use for a variety of purposes including as biofuels, adsorbents, and as soil amendments.

The Chemistry of Phenol-Formaldehyde Resin Vulcanization of EPDM: Part I. Evidence for Methylene Crosslinks

1995 ◽  
Vol 68 (5) ◽  
pp. 717-727 ◽  
Author(s):  
Martin van Duin ◽  
Aniko Souphanthong
Keyword(s):  
Molecular Weight ◽  
Phenol Formaldehyde ◽  
Polymer System ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Reaction Products ◽  
Cure Reaction ◽  
Weight Model

Abstract The application of phenol-formaldehyde resins as crosslinking agents is increasing in importance due to the good high temperature properties of the corresponding vulcanizate and the use in thermoplastic vulcanizates. With respect to the chemistry of phenol-formaldehyde cure (reaction mechanism and structure of crosslink) there are still problems that have to be resolved. The reaction products of the phenol-formaldehyde resin curing of EPDM, contain 2-ethylidene norbornene (ENB) as the third monomer, have been studied. Since such an investigation is rather difficult to perform for the polymer system, a low molecular weight model for EPDM was used: 2-ethylidene norbornane (ENBH). Reaction of ENBH and a resole results in scission of the dimethylene ether bridges, i.e. in degradation of the resole into mono-, bis- and terisooctylphenol units. These are consequently converted into products, consisting of two ENBH molecules linked by mono-, bis- and terisooctylphenol units. The solid resole seems to be a technological solution for storing phenol in combination with formaldehyde. These results support the use of 2-hydroxymethylphenol (HMP) as a low molecular weight model for the resole. At low temperatures and/or short reaction times HMP oligomers (= resoles) and HMP oligomers linked to one ENBH molecule are formed, which are converted into ENBH/HMP (1:1) condensation products. The reaction products of ENBH with both the resole and HMP are shown to contain methylene linked structures, as demonstrated by the formation of monisooctylphenol crosslinks and the presence of residual unsaturation and hydroxyl groups, besides chroman linked structures. This is the first experimental evidence that during phenol-formaldehyde resin cure of rubber, formation of methylene bridges occurs.

scholarly journals Metabolomics of Pseudomonas aeruginosa Treated by Atmospheric-Pressure Cold Plasma

2021 ◽  
Vol 11 (22) ◽  
pp. 10527
Author(s):  
Dehui Xu ◽  
Xinying Zhang ◽  
Jin Zhang ◽  
Rui Feng ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Atmospheric Pressure ◽  
Cold Plasma ◽  
Chemical Properties ◽  
Flight Mass Spectrometry ◽  
Active Particles ◽  
Plasma Device ◽  
Physical And Chemical ◽  
Plasma Activated Water ◽  
And Chemical Properties

With increasing drug resistance of Pseudomonas aeruginosa, a new sterilization method is needed. Plasma has been shown to be an effective method of sterilization, but no researchers have studied the effect of plasma on bacterial metabolism. In this paper, we studied the emission spectrum, liquid phase active particles, and other physical and chemical properties of a portable plasma device. Pseudomonas aeruginosa were then treated with activated water generated by surface plasma discharge. Using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, we obtained the differential metabolite pathways. The results showed that, after plasma activated water treatment, the carbohydrate metabolism of the bacteria was inhibited and the metabolic processes of protein and amino acid decomposition were enhanced. Therefore, water activated by atmospheric-pressure cold plasma can significantly change bacterial metabolites, thus promoting bacterial death.

Mechanical and chemical properties of Baghdadite coatings manufactured by atmospheric plasma spraying

2019 ◽  
Vol 378 ◽  
pp. 124945 ◽  
Author(s):  
D.Q. Pham ◽  
C.C. Berndt ◽  
U. Gbureck ◽  
H. Zreiqat ◽  
V.K. Truong ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Chemical Properties ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
And Chemical Properties

scholarly journals Overcoming the Blood-Brain Barrier: Functionalised Chitosan Nanocarriers

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1013 ◽  
Author(s):  
Anna E. Caprifico ◽  
Peter J. S. Foot ◽  
Elena Polycarpou ◽  
Gianpiero Calabrese
Keyword(s):  
Blood Brain Barrier ◽  
Chemical Properties ◽  
Brain Barrier ◽  
Hydroxyl Groups ◽  
Blood Brain ◽  
The Brain ◽  
Major Impediment ◽  
And Chemical Properties

The major impediment to the delivery of therapeutics to the brain is the presence of the blood-brain barrier (BBB). The BBB allows for the entrance of essential nutrients while excluding harmful substances, including most therapeutic agents; hence, brain disorders, especially tumours, are very difficult to treat. Chitosan is a well-researched polymer that offers advantageous biological and chemical properties, such as mucoadhesion and the ease of functionalisation. Chitosan-based nanocarriers (CsNCs) establish ionic interactions with the endothelial cells, facilitating the crossing of drugs through the BBB by adsorptive mediated transcytosis. This process is further enhanced by modifications of the structure of chitosan, owing to the presence of reactive amino and hydroxyl groups. Finally, by permanently binding ligands or molecules, such as antibodies or lipids, CsNCs have showed a boosted passage through the BBB, in both in vivo and in vitro studies which will be discussed in this review.

scholarly journals Changes in microbial and chemical properties of rough rice treated with cold plasma by storage temperatures and periods

2017 ◽  
Vol 24 (7) ◽  
pp. 908-914
Author(s):  
Koan Sik Woo ◽  
Hae In Yong ◽  
Cheorun Jo ◽  
Seuk Ki Lee ◽  
Byong Won Lee ◽  
...  
Keyword(s):  
Cold Plasma ◽  
Chemical Properties ◽  
Rough Rice ◽  
Storage Temperatures ◽  
And Chemical Properties

scholarly journals Purity and structural composition of lignin isolated from Miscanthus x giganteus by sub-critical water extraction with associated modifiers

2020 ◽  
Vol 1 (1) ◽  
pp. 1-12 ◽  
Keyword(s):  
Paper Industry ◽  
Chemical Properties ◽  
Value Added ◽  
Hydroxyl Groups ◽  
Physical And Chemical Properties ◽  
Miscanthus X Giganteus ◽  
Lignin Recovery ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

Lignin is an industrial by-product produced from the pulping and paper industry, where the process generates lignin in the form of lignosulphonates. While there are many applications for lignin, there are all low value and attempts to add value to lignin are hindered by its complex physicochemical nature and the presence of sulphur. Adopting the biorefining concept, the study evaluates the impact of direct (DE) and sequential extraction (SE) of Miscanthus x giganteus using sub-critical water with associated modifiers; ethanol and carbon dioxide on the physical and chemical properties of the extracted lignin. Isolated lignins were characterised by a Fourier Transform Infrared Spectroscopy (FTIR). Although higher delignification was achieved by DE and SE about 81.5% and 58.0%, respectively, the lignin recovered from the SE process showed remarkably higher purity with 91.5%. Lignin recovery did not differ considerably for either processing method. FTIR revealed a qualitative reduction in the intensity of bonds corresponding to hydroxyl groups for the lignin derived from DE rather than SE processing routes. These indicated that the lignin derived from SE had potential for subsequent preparation in lignin value-added bio-based materials.

scholarly journals SYNTHESIS, CHARACTERISATION AND APPLICATION OF PHENOL-FORMALDEHYDE RESIN BLENDED WITH SULPHONATED PHYLLANTHUS EMBLICA, LINN., CARBON

2013 ◽  
Vol 9 (2) ◽  
pp. 1921-1932
Author(s):  
R. K. Seenivasan ◽  
D. Ragavan ◽  
A. Girija ◽  
R. Muthuramalingam
Keyword(s):  
Plant Material ◽  
Phenol Formaldehyde ◽  
Low Cost ◽  
Equilibrium Constants ◽  
Chemical Properties ◽  
Phenol Formaldehyde Resin ◽  
Composite Resins ◽  
Formaldehyde Resin ◽  
Phyllanthus Emblica ◽  
Weight Percentage

Phenol – Formaldehyde Resin (PFR) is blended with Sulphonated Phyllanthus emblica, Linn., Carbon (SPEC) in various proportions by weight percentage (0-50%w/w). A few composite cation-exchangers were prepared by varying the amount of SPEC (a source of cheap and renevable plant material) in the blends from 10 to 50% (w/w). Reaction conditions for the preparation of blends were optimised. IR spectra, TGA traces, and SEM photos were taken for the characterization of  resins. Physico-chemical, properties of the composite resins have been determined. The composites are insoluble in various solvents and reagents and stable towards heat.   Cation exchange capacity (CEC) of the composite resins, decreased with the increasing percentage of SPEC in the blend. Thermodynamic equilibrium constants (lnK) are calculated for H+ - Zn2+ exchanges on the resins having a different amount of SPEC. Thermodynamic parameters are also calculated and suitable explanations are given. The composites up to 20% (w/w) blending retains all the essential properties of the original PFR, since the Phyllanthus emblica, Linn., is the low cost, freely available plant material. Therefore, the composites could be used as low cost ion-exchangers, when SPEC partly replaces the original PFR up to 20% (w/w) blending without affecting the properties of PFR.

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