Effect of phosphite loading on the mechanical and fire properties of palm-based polyurethane

Fire-retarding polyurethane (PU) composite was produced by adding 2,4-ditert-butylphenyl phosphite (FR) to palm-based monoester resin with loading percentage of 0, 2, 4, and 6 wt%. The Shore D hardness index increased marginally with increasing FR content. However, the impact and flexural strengths decreased with increasing FR loading attributed to the weak interfacial bonding between FR and PU matrix. The fire test indicated lowering of burning rate (from 5.30 mm s-1 to 2.80 mm s-1) as the loading percentage of FR increased. The combustion enthalpy of the composites also decreased with higher loading percentage of FR

Properties of Structural Lightweight Concrete Filled with Palm-Based Polyurethane

Four experiments were conducted to characterize the properties of palm-based polyurethane (PU) foam in lightweight concrete. The PU foam was synthesized from palm kernel oil-based polyol reacted with 2, 4-methylene diphenyl diisocyanate. Polyurethane as lightweight aggregate was mixed with ordinary cement, sand, and water to form lightweight concrete. The microstructure of PU aggregate can be accessed from optical micrographs. Density, compressive strength, distribution of fine aggregate, and the interfacial zone were also investigated. The result showed that palm-based lightweight concrete has excellent compressive strength (17.5 MPa), and fulfilled the minimum strength requirement for structural concrete. Palm-based lightweight concrete with 0.6 w/c ratio and 3% w/w PU system achieved 1770 kg/m3 presented uniform dispersion of aggregate and excellent mechanical bonding

Chemistry Outreach Program and its Impact on Secondary School Students

AbstractChemistry is one of the most difficult subjects and usually feared by the students in elementary schools. Some of the students in Malaysia, especially in the rural area, they memorized experiments and the theories without really understand the beauty of chemistry. They also believed that the chemistry experiment can only be done in the laboratory equipped with a huge fume hood since all of the experiments are dangerous, explosive and costly. Chemistry outreach program held by a team from Universiti Kebangsaan Malaysia was meant to change the perspective of the elementary students towards chemistry and to develop their interest in exploring the beauty of chemistry. The program took place in Perlis as part of the Science on Wheels Program organized by National Science Centre. Few experiments using chemicals which can be found in daily life were first demonstrated and explained. Then the students were given chances to try on their own. They were also asked to relate what they had learned from the experiments to the phenomenon that occurred in the world. Survey on knowing their interest in chemistry before and after the experiments was given and analyzed. The results showed that the level of liking chemistry and choosing chemistry as one of the career option depended mainly on the exposure towards chemistry. The result showed that 80% of the students were interested in chemistry after they performed the experiments compared to 72% who were interested in the chemistry subject taught in school prior to the experiment. The 8% increment was possibly a reflection of the effective learning through experiment. Overall, 58% of students were interested to choose chemistry as their future career and suprisingly it was not depended on the background of the family. The chemistry outreach program really gave the impact on the elementary students and reached their hearts and should be continued from time to time to attract students to science and technology

Physical and Mechanical Properties of Palm Kernel Oil-Based Polyester Polyurethane/Multi-Walled Carbon Nanotube Composites

In this study, polyurethane (PU) films from palm kernel oil-based polyester (PKO-p) incorporated multi-walled carbon nanotubes (MWNTs) are prepared via a evaporative casting method. Nanoparticle fluid dispersions containing 0.02%,0.03%, and 0.05% wt. of MWNTs are added into PKO-p based resin and mixed by digital probe sonicator for 30 min followed by mixing with isocyanate to produce PU-MWNTs composite films. The mechanical properties, swelling, water vapour transmission rate (WVTR) and conductivity of the PU-MWNTs composite films are examined. Resultsshow that the toughness (T) or flexibility, the tensile strength (TS), and Young’s modulus (YM) values of PU-MWNTs composite films increase with the increasing concentrations of MWNT. In contrast, the water vapour transmission rate (WVTR) and swelling test of PU-MWNTs composite films decrease with the increase of MWNT concentrations. For conductivity testing, the film with 0.05 wt.% MWNT (PU-5) has the highest conductivity value at 2.19 x 10-9 S cm-1. Insummary, incorporation of MWNTs has improved the mechanical properties of the polyurethane composites films

Bio-based polycationic polyurethane as an ion-selective membrane for nitrate tapered optical fiber sensors

A novel bio-based polycationic polyurethane as an ion-selective membrane for nitrate sensing was successfully developed. In this work, the intermolecular interactions at active polymeric sites play a primary role in selective nitrate-ion detection. From the experiment, FTIR shows a significant shift from 1543 cm−1 to 1548 cm−1 in N-H bending, indicating that intermolecular interactions occur between the polycationic polyurethane and nitrate. AFM shows that the surface roughness of the polycationic polyurethane decreases from 95.7 nm to 12.2 nm after immersion in nitrate solution. Meanwhile, FESEM images show that the bright area, which represents the hard segment of polycationic polyurethane, decreases after immersion, indicating that the nitrate is interacting with the hard segment of the polycationic polyurethane via intermolecular interaction. Furthermore, EIS shows that the conductivity increases from 2.84 × 10−11 to 5.34 × 10−11 S cm−1 after ion exchange occurs between the iodide and nitrate on the polycationic polyurethane. To assess the sensing performance, the sensor probe is fabricated by coating the polycationic polyurethane thin film on the tapered region of an optical fiber. Rapid detection, good repeatability, and a sensitivity of 5.94 × 10−2µW/ppm are obtained for nitrate detection using the above bio-based-sensing material. The selectivity study also shows that the sensing material possesses high affinity toward the nitrate ion

Physical leaching and toxicity characteristics of PG76 binder modified with rediset

Asphalt binder, as one of the pavement components, is exposed to heat and rainfall. Polymer modified asphalt binder is a good alternative to withstand the weather in tropical countries. By utilizing warm mix asphalt additive, the high compacting and mixing temperature can be reduced. However, the impact to the environment and its characteristic towards high temperature need to be evaluated before putting it to use. In this study, the physical properties, thermal characteristics, and leaching and toxicity of PG76 incorporated with Rediset LQ were investigated. The Tank Leaching Test was carried out to mimic the worst scenario of flood event effect on the asphalt binder. The results of physical tests denote that the new material has relative consistency, while the thermal analysis indicates that the materials are stable beyond their mixing and compaction temperature. The decomposition starts at temperature > 360°C and ends at temperature <500°C for all samples. The tank leaching test also found that the materials are safe to be used as pavement materials, because the heavy metal elements from the leachate are below the maximum allowable volume by the World Health Organization and the United States Environmental Protection Agency

Physical, leaching, and toxicity characteristics of PG76 binder modified with Rediset

Asphalt binder, as one of pavement component is exposed to heat and rainfall. Polymer modified asphalt binder is a good alternative to withstand the weather in tropical countries. By utilizing warm mix asphalt additive, the high compacting and mixing temperature can be reduced. However, the impact to the environment and its characteristic towards high temperature need to be evaluated before putting it to use. In the study, the physical properties, thermal characteristics, and leaching and toxicity of PG76 incorporated with Rediset LQ were investigated. The Tank Leaching Test was carried out to mimic the worst scenario of flood event effect on the asphalt binder. The results of physical tests denote that the new material has relative consistency while the thermal analysis indicates that the materials are stable beyond their mixing and compaction temperature. The decomposition starts at temperature > 360°C and ends at temperature <500°C for all samples. The tank leaching test also found that the materials are safe to be used as pavement material because the heavy metal elements from the leachate are below the maximum allowable volume by the World Health Organization and the United States Environmental Protection Agency

Thermal and fire resistant properties of palm kernel oil and soybean oil-based polyurethanes

Thermal and burning properties of palm kernel oil and soybean oil-based polyurethanes were compared. Monoester with hydroxyl end group was prepared by reacting the palm kernel oil (PKO) and the soybean oil (SBO) with polyhydric compound consisting of diethanolamine/ethylene glycol and potassium acetate as the catalyst. The esterification and condensation reactions were conducted with the ratio of the vegetable oils to the polyhydric compound of 80:20. The monoester was then reacted with 2, 4-diphenylmethane diisocyanate to produce the polyurethane via addition polymerization. The thermal properties were compared through differential scanning calorimetry (DSC) analysis, thermogravimetry (TGA) analysis, bomb calorimetry, dimensional stability test and fire retarding test. SBO-based polyurethane foam had lower entalphy then the PKO-based polyurethane foam with values of 7151 cal g-1 comapred to 7223 cal g-1. Similarly, the TGA analysis indicated that the percentage of weight loss of the former was also lower (91.0%) then the latter (92.3%) with stable temperatures, Tstable at 196 and 198 oC, respectively. The burning rate of the SBO-based polyurethane foam was 0.6-1.2 mm¥s-1, lower then the PKO-based polyurethane foam which was 1.1-1.6 mm s-1. However, the dimensional stability test showed that the shrinkage and expansion values were lesser for the SBO-based polyurethane foam compared to the PKO-based polyurethane

A mini scale batch reactor for the production of palm‑based polyol

An investigation on a batch production of palm kernel oil polyol (PKO-p) was conducted via esterification and condensation. The process design was thoroughly studied as a preliminary step for future upscaling. The process variables included necessity of vacuum pump, controlling of heating rate, recording the production time, nitrogen gas flow and agitator speed. About 250 mL PKO-p was successfully synthesized within 3 h. Vacuum pressure was applied to haul out moisture from the system. The control of heating rate and production time are vital to avoid sudden oxidation