Pencirian permukaan kakisan keluli karbon dengan kehadiran konsortium bakteria penurun sulfat dalam persekitaran bergas CO2

Tingkah laku kakisan keluli karbon API 5L X65 dengan kehadiran bakteria penurun sulfat (SRB) dalam persekitaran CO2 adalah dikaji. Uji kaji yang dijalankan bagi meneliti tingkah laku kakisan adalah ujian kehilangan berat dan analisis permukaan. Spesimen keluli karbon didedahkan kepada medium kawalan (tanpa konsortium bakteria) dan dengan kehadiran konsortium SRB selama 10 hari dalam aliran gas CO2 yang berterusan. Biofilem, produk kakisan dan kedalaman lubang yang terhasil dicirikan dengan mikroskopi elektron imbasan pancaran medan (FESEM), spektroskopi tenaga serakan (EDS), mikroskop fokus tak terhingga (IFM) dan belauan sinar-x (XRD). Keputusan daripada ujian kehilangan berat mengesahkan bahawa spesimen dalam keadaan kawalan membentuk kakisan seragam. Manakala analisis IFM membuktikan bahawa sampel dengan kehadiran konsortium SRB menggalakkan penghasilan kakisan setempat. Hal ini merujuk kepada nilai kadar penembusan liang yang lebih tinggi daripada kadar kakisan seragam dengan kehadiran konsortium SRB. Penelitian menerusi FESEM-EDS membuktikan kehadiran sulfur pada spesimen logam yang terdedah kepada SRB dalam persekitaran CO2 yang menyokong pembentukan lapisan FeS. Seterusnya, pencirian XRD mengesahkan pembentukan Fe3 C dan FeS dalam sampel yang terdedah kepada SRB

Significance of Oxirane Rings in Epoxidized Palm Oil and Effects on the Coating Performance: Comparison between Epoxidized Unripe Palm Oil and Epoxidized Used Cooking Oil towards Adhesion Performance

In this study, epoxy coatings made up from petroleum-based epoxy resin mixed with two different types of palm oils were prepared and compared. The commercial epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) were formulated with epoxidized unripe palm oil (EPO) and another one with epoxidized used cooking oil (ECO) at four different ratios (0:100, 10:90, 20:80 and 30:70). The EPO and ECO were prepared through generated in situ of performic acid (HCOOH) and hydrogen peroxide (H2O2) by a fixed molar ratio of 1:5:4 mol/mol (EPO/ECO: HCOOH:H2O2). The reaction took place at constant temperature (45 °C) with continuous stirring for 150 min to obtain 95.5% oxirane conversion with 90.0% yield. The EPO and ECO were characterized by using Fourier Transform Infrared (FTIR) spectroscopy analysis. X-Cut and Cross-Cut methods were used in the test performance of adhesion strength. The results obtained from adhesion test for EPO were good as the coatings only experienced small trace of peeling. On the other hand, only minimal performances were obtained from the ECO coated metal. This was due to the presence of oxirane in EPO as compared to that of in ECO. EPO has a potential to replace petroleum-based resin in epoxy coating formulation according to its remarkable performances

Microstructure studies of bio-water-based coated material for metal exposed in various corrosion environment / Najmiddin Yaakob …[et al.]

The basic formulation of paint consists of a pigment, binder, solvent and additives. Nowadays, all of the components in paint are made from hazardous chemicals which are harmful to the environment. One of the most important aspects in paint formulation is solvent. Solvent is used to carry the solid components of paint allowing consistency of application by brush, roller, and spray or dipping. The choice of solvent also affects the flow of the paint after it has been applied so that the film develops the correct surface appearance. The paint film wets the substrate to which it has been applied thus maximizing adhesion to the surface. These commonly used solvent are organic chemicals which are harmful to the environment and thus leading to the problem in the application of the paint due to the hazardous constituents. Organic solvent based paints are still a serious problem for painters in the construction sector and that there are no general indications, that the problems are going to be solved. On top of this, it showed that painters are at risks for heavily exposure to organic solvents, for instance floor treatment and painting steel constructions. The bio-water based coated material is based from palm oil methyl ester as the solvent. Palm oil methyl ester is environmental friendly and does not contain any volatile organic compounds which are harmful to the environment since it is made of 100% vegetable origin.. It is also an odorless solvent. The formulation of the bio-water-based consists of a pigment, binder, additives and palm oil methyl ester. The formulation of the bio-water-based coating material for metal will be optimized by testing on the adhesion and corrosion test in various corrosive environments. Due to this matter, micro structure studies of the bio-water-based coated material for metal exposed in various corrosive environments will be conducted