Abstract In this work, the mechanical and barrier properties were examined for Polypropylene (PP) film in which the surface of the film was modified by Oxygen plasma treatment. The PP film was treated in various intervals of time of 60 s, 120 s, 180 s, 240 s and 300 s with three various RF power settings of 7.2 W, 10.2 W, 29.6 W. The contact angle was measured to characterize the wettability. The oxygen functional groups were generated on the surface of oxygen modified PP which was observed by Fourier transform infrared spectroscope and it was resulted in the improvement of wettability. The surface morphology and roughness of the PP films before and after the oxygen plasma treatment was analyzed by Atomic Force Microscopy (AFM). It was found that the roughness of …show more content…
Testing was performed at 23 ºC under the condition of 0% RH at 1 atm with the standard of ASTM D3985. Measurements were taken at three times and the average value was calculated. All specimens were conditioned at ambient conditions. Water-vapour Transmission Rate (WVTR) The Water vapor Transmission Rate (WVTR) of the treated and untreated PP samples was calculated by Mocon Permatran, according to the standard of ASTM F 1249 – 90. The tests were carried out at 35 ºC under the condition of 100% RH. It was repeated for three times and the average mean values were reported. All specimens were conditioned at ambient conditions. Results and Discussions AFM analysis The surface morphology and the surface roughness of the untreated and treated PP samples were investigated by AFM. The Figure 1 represents the AFM images in a three dimensional view of untreated and treated samples in a time of 60s with various power rates. The scan size of all the images is 5×5 μm2. Evidently, the oxygen plasma treatment modified the surface morphology of the PP
ABSTRACT In this study, a halogen-free phosphorous–nitrogen synergistic flame retardant, poly-N-aniline-phenyl phosphamide (PDPPD), was synthesized. The Fourier transform Infrared spectroscopy, nuclear magnetic resonance spectroscopy, and elements analysis data confirmed the structure of PDPPD. The essential flame retardant of FR PA66 was polymerized with PA66 pre-polymer and PDPPD pre-polymer, prepared from PDPPD and adipic acid. The limit oxygen index and UL-94 test results of the flame retardant of FR PA66 reached 28% and V-0, respectively, when the contents of PDPPD pre-polymer were 4.5 wt%. The thermogravimetric and differential scanning calorimetry results demonstrated that the initial decomposition temperature of flame retardant of FR PA66 was 43 °C lower than that of pristine PA66 from 385 to 342 °C; however, the peak decomposition temperature was 36 °C higher than that of pure PA66 from 437 to 473 °C, when the contents of PDPPD pre-polymer reached 4.5 wt%. Flame retardant mechanism was studied by cone calorimeter and SEM-EDX, confirming that the HRR, THR, and TSP decreased slightly, and PDPPD functions according to the gas phase flame retardant mechanism.
To obtain a detailed knowledge on the effect of Sensitization on the hardness of the samples, two kinds of hardness determination tests were performed.
Thin film coatings of ceramic materials are widely used to safeguard materials against corrosion, wear resistance, and thermal conductivity [1, 2]. The objective of this work is to increase the thermal resistivity and thereby improve the mechanical properties of the materials. In this work thin film of Ceria stabilized Zirconia was formed and is applied on the area where the heat transfer occurs the most and is used to reduce its effect of temperature. These coatings are used to protect parts from big and prolonged heat loads by utilizing thermally insulated materials which can undergo a significant temperature difference between the initial material and the coating surface [3]. Many new materials have been developed, but steel remains the principal construction material for automobiles appliances, and industrial machinery. Since steels are vulnerable to aggressive chemical environments or atmospheric oxidation, metal coating is necessary to provide various degrees of protection through hot-dipped and electroplating process to tough polymers and flame-sprayed ceramics. In general corrosive atmospheres contain more than one active material, and the coating must resist dissemination by a combination of oxidizers, solvents, or both. Thus, the best hurdle is one that resists corrosion [4]. The obligatory thin films have been attained by using spray pyrolysis coating method. Spray pyrolysis technique involves spraying of a solution containing soluble salts of the desired compound on to preheated substrates, where the constituents react to form a chemical compound [8, 9]. Both, dense and porous structures can be deposited by spray pyrolysis which can also be achieved on large substrates by scaling up the equipment. It has capability to...
We investigated the effects of sunlight exposure on leaf stomata density. Our hypothesis stated that stomata density in the leaves with more sunlight exposure should be greater because in the leaves exposed to sunlight appeared to be healthier than the leaves in the shade. Our hypothesis was rejected, and the leaves with little to no sunlight exposure had a greater stomata density.
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
...ed, but when the annealing time to 20 s the films maintained a pure perovskite phase. The conventional oven annealing process produced a mixture of pyrochlore and perovskite crystals at 600 ° C at an annealing time of 2 h. When the PZT films were annealed at 650 °C for 2 h all films assumed pure perovskite crystal structures. The Pb content also had an effect on the crystallization of the PZT film. It was determined that excess PZT increased crystallization toward the perovskite phase. Although excess Pb increase crystallization it worsens the morphology. PZT films deposited with excess Pb tend to have a rougher surface.
Cellular prion proteins are normally occurring glycoproteins found on the outer surface of neuronal cells. They are also expressed by most other cells found in the body. Prion proteins are attached to the plasma membrane by a C-terminus glycosyl-phosphatidylinositol (GPI) anchor. The prion protein exists in two conformational states: a cellular α-helix-rich isoform (PrPc) and the prion disease-associated β-sheet isoform (PrPsc). In humans, PrPc is composed of 253 amino acids and is encoded by the PRNP gene, which is located on chromosome 20 (Adams et al, 2014). The N-terminal domain of the protein contains a highly conserved octapeptide repeat (OR) sequence made up of a PQGGGWGQ peptide sequence. The octarepeat contains histidine
Figure 1.4 – Schematic of cleaning of a substratum using plasma glow discharge. Note the removal of adsorbed molecules by bombardment on the surface and the presence of dangling bonds (Wikipedia – the Free Encyclopedia).
Engineered surfaces with tailored properties such as large surface area or specific reactivity are used routinely in a range of applications such as in fuel cells and catalysts. The large surface ar...
Different methods are employed to protect the material from degradation. The Centre for Engineered Coatings provides a complete overview of the concept of surface engineering and its application in diversified fields. The centre is well equipped with both the conventional and the current state of the art surface modification techniques and reviews both the advantages and limitations of each technology. The centre through its ongoing R&D efforts strides to help Indian industries to achieve their full potential and competence in area of surface engineering and coatings.
Živković, Snežana; Takić, Ljiljana; Živković, Nenad UNAPREĐENJE EKOLOŠKIH PERFORMANSI PRIMENOM STANDARDA ISO 14001 - STUDIJA SLUČAJ.. Chemical Industry & Chemical Engineering Quarterly. 2013, Vol. 19 Issue 4, p541-552. 12p. DOI: 10.2298/CICEQ120513088Z. ,
LAB REPORT 1st Experiment done in class Introduction: Agarose gel electrophoresis separates molecules by their size, shape, and charge. Biomolecules such as DNA, RNA and proteins, are some examples. Buffered samples such as glycerol and glucose are loaded into a gel. An electrical current is placed across the gel.
After the first specimen rod was done, the percent deviation of glass, copper, stainless steel and aluminum have increased noticeably. One of the reasons is that the metal tube was not able to return back to its original temperature or its normal state within a short period of time, even though it was cooled down by running under the water. Another factor was that the thermometer also could not return to the room temperature.
Morphological characterization was carried out via SEM analysis. The micrographs of fractured surfaces of samples P-0.1D-1PO are represented in Figure 2. Figures 2 (a) and 2 (c) are related to the SEM images while figures 2 (b) and 2 (d) are the element mapping images. Moreover, figures 2 (a) and (b) demonstrate the samples before the crosslinking process and figures 2 (c) and (d) are attributed to the samples after the
Then the ITS test is performed on the sample at 77°F (25°C) at a loading rate of 2in/min.