Papers by Keyword: ENR 50

Abstract: Previously, the addition of silicon dioxide (SiO₂) improved the homogeneity of polymethyl methacrylate/50 % epoxidised natural rubber (PMMA/ENR 50) blend. However, the presence of SiO₂ agglomerates limits its overall performance. The formation of these agglomerates was due to the hydrogen bonding interaction that form between the oxygen atoms in silanol groups (Si-OH) and hydrogen atoms from the surrounding moisture. Therefore, in this study, SiO₂ were modified with dodecanoic acid (DOA) to reduce the number of Si-OH on the SiO₂ surface using esterification technique. Interestingly, it was found that the addition of DOA modified SiO₂ (D-SiO₂) improves the homogeneity of PMMA/ENR 50 blend. However, the amount of DOA used in the modification affect the capability of forming hydrogen bonding with the neighbouring of polymer chain. Different amounts of DOA were used upon the surface modification of SiO₂ filler and then were added into PMMA/ENR 50 blends doped with lithium tetrafluoroborate (LiBF₄)_. The films were prepared by solvent casting technique. CHNS analysis proven the increases of percentage of carbon atoms in D-SiO₂. The attachment of DOA on SiO₂ surface was confirmed using Fourier transform infrared spectroscopy (FTIR) and ionic conductivity of PMMA/ENR 50/LiBF₄ filled D-SiO₂ films was measured by electrochemical impedance spectroscopy (EIS). The result shows the blend properties and ionic conductivity of PMMA/ENR 50 filled D-SiO₂ films was improved due to surface modification of SiO₂ filler.

Abstract: Previously, it was found that the addition of SiO₂ filler can improve the homogeneity and enhance the ionic conductivity of lithium tetrafluoroborate (LiBF₄) doped polymethyl methacrylate/50 % epoxidized natural rubber (PMMA/ENR 50) blend from 6.21 x 10^-7 Scm^-1 to 5.26 x 10^-6 Scm^-1. Unfortunately, this SiO₂ filler tend to agglomerates thus obstructing the smoothness in the transportation of lithium ion in the polymer blend matrix. This unruly phenomenon was due to the formation of hydrogen bonding between the oxygen atom of SiO₂ and the hydrogen atom from the moisture. Therefore, in this study, this SiO₂ filler was modified using hydrochloric acid (HCl) to reduce the formation of hydrogen bonding between SiO₂ and moisture. It was found that the modification was able to reduce the hydrogen bond in SiO₂ filler. The CHNS analysis shows that the percentage of hydrogen reduces as concentration of acid increased. This was further confirmed from the FT-IR analysis in which the peak corresponding to Si-OH was reduces meanwhile the peaks corresponding to Si-O-Si increases as HCl concentration increased. As a result, the homogeneity of the blends was further improved. However, the ionic conductivity of the system was found slightly reduce by few magnitudes. Temperature dependence ionic conductivity of LiBF₄ doped PMMA/ENR 50 filled HCl-SiO₂ electrolytes shows nonlinear trend indicates that the system not obeys Arrhenius equation.

Abstract: The lattice energy of the doping salt for a polymer electrolyte is crucial because it affects the ionic conductivity of the polymer electrolyte system. It is also known that the lattice energy of a salt depends on the size of the anion. The larger the anion the lower the lattice energy of the salt. Therefore, in this study the effect of the anion size of various doping salts; LiNO₃ and LiN(CF₃SO₂)₂ with lattice energy of 848 kJ/mol and 489.4 kJ/mol, respectively were investigated and compared with LiCF₃SO₃ salt (735 kJ/mol) on the electrical properties of poly (methyl methacrylate) (PMMA) / epoxidised natural rubber (ENR 50) blend film. All the doped PMMA/ENR 50 films were prepared by solvent casting technique. Surprisingly, though LiN(CF₃SO₂)₂ exhibited the lowest lattice energy, it displayed the lowest ionic conductivity value of 10^-8 S/cm at room temperature as compared to LiNO₃ and LiBF₄ due to its poor coordinating power with the polymer. This was confirmed from the FTIR analyses. Further investigation on the dielectric behaviour of the doped PMMA/ENR 50 films were also reported.

Abstract: The effects on properties of recycle nitrile glove (NBRr) filled Epoxidised Natural Rubber (ENR 50) was studied. Compound was prepared by two roll mill at five different compositions of NBRr (5, 15, 25, 35 and 50 phr). Two different size ranges of NBRr particles i.e., 300μm-700μm (fine) and 3cm-5cm (coarse) were used. The properties of cure characteristics (cure time, scorch time, minimum torque, and maximum torque) and swelling test were determined. Results indicated that the incorporation of fine size NBRr loading on ENR 50 provides better improvement both on cure characteristics and swelling behaviour mainly at 15 phr of NBRr compared to the coarser size NBRr particles.

Abstract: The effect of recycled silicone catheter (rSC) on tensile properties (tensile strength, modulus at 100% elongation and elongation at break) and morphology of recycled silicone catheter filled epoxidised natural rubber (ENR 50/rSC) vulcanizates were studied in loading range of 0 to 50 phr with two different size; fine (300-600μm) and coarse (1-2 cm). For tensile properties, tensile strength, modulus at 100% elongation (M₁₀₀) and elongation at break (E_B) for both ENR 50/rSC fine and coarse vulcanizates show increment up to 15 phr but then decreased as the rSC content increased. Comparison between ENR 50/rSC fine and coarse vulcanizates indicates that ENR 50/rSC fine vulcanizates has better tensile properties than ENR 50/rSC coarse vulcanizates due to better dispersion and filler-rubber interaction as proven in morphological study. The results indicate that the morphology of ENR 50/rSC fine vulcanizate is better than that of ENR 50/rSC coarse vulcanizates in which fine rSC well bonded with ENR 50.

Abstract: This study investigates the properties of blends made from low density polyethylene (LDPE) with various levels of thermoplastic soya spent powder (SSP). The thermoplastic TPSSP content was varied from 5 to 20wt % whereas epoxidised natural rubber with 50 mol % (ENR 50) act as compatibilizer to improve the interfacial adhesion between low density polyethylene and thermoplastic TPSSP. The effect of the addition of ENR 50 on the LDPE/thermoplastic TPSSP was measured by using tensile test and thermal behaviour. The tensile strength and elongation at break (E_b) decreased with increasing TPSSP content. However, the addition of ENR 50 resulted in the increment of tensile strength and E_b LDPE/TPSSP blends.

Abstract: The present study focuses on preparation of ENR-50/PEMA-NH4CF3SO3 proton conducting polymer electrolytes by solution casting technique. Conductivity increases with NH4CF3SO3 concentration up to 40 wt.% but decreases with further increase in salt content. The temperature dependent conductivity study shows that the conductivity-temperature behaviour of ENR-50/PEMA-NH4CF3SO3 electrolytes follows the VTF rule. DSC studies show that the Tg increases with increase in salt content. This means that the increase in conductivity of ENR-50/PEMA-NH4CF3SO3 is incorrelated to the increase of the segmental motion of the host polymer chains but may be attributed to the increase in the concentration and migration rate of charge carriers.