Papers by Keyword: Polymeric Film

Abstract: The market of hair gel products in Thailand steadily grows with the changing trend of fashion every year. The main component of the hair gel products is the fixative polymer, which plays a role in hair styling properties including stiffness and curl retention. Properties of the hair styling product depending on hair types and climates must be suitably improved for Thai hair. In this study, 10 %w/w gel solutions of polyacrylic acid, polyquaternium-86, polyvinylpyrrolidone (PVP), acrylates copolymer, and vinylpyrrolidone (VP) copolymers were cast as polymeric thin films. The film properties such as mechanical properties, wettability, and crystallinity were characterized afterwards. As a result, the highest puncture strength of 2.2 N/mm² was found from PVP-K90 film (500-700 μm thick). Whereas, VP/vinyl acetate (VA) copolymer film was the most flexible with 42.5% elongation. For water contact angle analysis, it was noticed that VP copolymers had the angle of ~50^o indicating the moderate wettability. The x-ray patterns of raw materials, polymeric films, and humidified films were varied especially for PVP-K30. Morphologies of the Thai hair samples coated with the fixative polymers were visualized through SEM. After storing coated hair samples in the humidified atmosphere (95±2% Relative humidity), acrylates copolymer, VP/Methacrylamide/Vinyl Imidazole copolymer, and VP/VA copolymer appeared the humidity resistance suitable for Thai hair styling gel.

Abstract: The surface of steel coated with Cr³⁺-based passivation layer and polyethylene therephtalate (PET) polymeric film was investigated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). This coating was applied to the steel surface through a co-lamination industrial procedure. As well, the coated steel porosity was characterized by BET (Brunaer, Emmert, Teller) gas adsorption technique. Basic aspects of the polymer adhesion to the passivated steel were also studied by determining the force and energy adhesion between them. The AFM results showed that the PET coating presents roughness in the nanometer scale. XPS diagrams indicated the absence of surface contaminants and flaws on the applied coating and low contaminant levels on the Cr layer and absence of Cr⁶⁺ peaks after coating removal. This material can be a environmental compliant alternative to replace tinplate and Cr⁶⁺ conversion layer in the food industry, being compatible with the packed product.

Abstract: In this paper a mathematical model for prediction of moisture gain over storage time for binary mixtures of moisture sensitive products was developed, which considered both the moisture transfer through the polymeric film to the headspace and from the headspace to the product. Moisture content within the product was assumed to be uniform for a given time and to relate to the headspace humidity by the GAB sorption isotherm. The transient period of these experiments was used to estimate the mass transfer coefficients. The model was validated by monitoring the moisture take up by breakfast cereal and chocolate powder mixture in different materials, oriented polypropylene (OPP) and low density polythelene (LDPE), during storage at 25°C and 75% relative humidity (RH). The model showed that for mixes some bias was clear, particularly for the cereal, probably owing to interactions between the products. If the resistance of the product to moisture uptake were not taken into consideration, the model would over-predict the experimental results by up to 20%.

Abstract: Polymeric compounds are of great interest as corrosion inhibitors in acidic environment due to their inherent stability. Polymeric film is effectively used for the protection of metals partly owing to their capacity to act as a physical barrier between the metal surface and the corrosive environment. In this paper, a cation polyelectrolyte inhibitor (Quaternary Polyethyleneimine, QPEI) was prepared. The quality and inhibition efficiency of QPEI self-adsorbed films were studied by polarization curve and electrochemical impedance spectroscopy, respectively. The compositions and morphologies of the polymer film on the steel surface were examined with the aids of SEM and XPS, respectively. The results showed that QPEI could greatly retard the corrosion of iron in sulfuric acid, which was attributed mainly to the protective QPEI film formed on the surface. Meanwhile, the inhibition of QPEI could be supposed as a mixed process, in which both cathodic and anodic corrosions were simultaneously restrained. Based on the results of XPS and SEM, it could be evidenced that the QPEI can form a protective polymer layer on the metal surface by adsorption.

Abstract: This paper presents experimental results on the mechanical performance of advanced carbon/epoxy composites with embedded polymeric films. The composite laminates with polymeric films, which are potentially used as a sensor/actuator carrier for structural health monitoring applications, were investigated under various mechanical loadings including low velocity impact, single lap shear and short beam shear. The preliminary work showed that embedment of those polymeric films does not degrade, but could significantly improve, the mechanical properties of the composite laminates.

Abstract: An organic compound of dihexyl-contained triazine dithiol was specially synthesized for surface modification of magnesium alloy AZ91 in order to improve its corrosion resistance. The nano-scale polymer film on the surface of AZ91 was created with the synthesized compound by means of electrochemical measuring system called as polymer plating in the electrolytic solution. The modified surface of AZ91 had the peculiar functional characteristic of water repellency to inhibit corrosion. Corrosion tests were carried out with methods of polarization curve and electrochemical impedance. The corrosion resistance was evaluated from corrosive current density and reactive resistance. When concentration of the compound was set on 8 mol/m3, the good corrosion resistance was obtained for low corrosive current density and high reactive resistance in NaCl aqueous solution at 303K.