CHEMICAL EPOXIDATION OF OLEIC ACID TO PRODUCE AB TYPE MONOMER FOR FATTY-ACID-BASED POLYESTER SYNTHESIS

Epoxides from vegetable oils are currently gaining more attention to replace petroleum-based monomers for polymer synthesis. As one of unsaturated fatty acids derived from vegetable oil, Oleic acid can be converted into epoxidized oleic acid by chemical epoxidation. Epoxidized oleic acid is a bifunctional monomer that has the potential to be used as raw material for fatty-acid-based polyester synthesis. This paper proposes the Taguchi-based optimization technique for in-situ epoxidation of oleic acid. The combining factors affecting the maximum yield were also determined to obtain a higher quality of epoxidized oleic acid in a relatively short time. Epoxidized oleic acid was characterized and tested for degradation. The characterization result showed the possibility of the polymerization reaction, and the kinetic study showed that the rate of epoxide degradation at room temperature follows second order with a reaction rate constant of2.7235 gr.mmol-1.day-1.

PREPARATION AND CHARACTERIZATION OF SPECIALTY NATURAL RUBBER LATEX CONCENTRATE

ABSTRACT Conventionally, specialty natural rubber (SpNR) latex, namely, deproteinized natural rubber (DPNR) latex and epoxidized natural rubber (ENR) latex, are prepared from low ammonia latex (LATZ) causing high material cost. To address this issue, the objective of this study is to prepare SpNR latex directly from freshly tapped NR latex. In this work, DPNR latex is prepared via a heat enzymatic hydrolysis process, while ENR latex is prepared via in situ epoxidation chemical modification process. In addition, both DPNR and ENR latex were concentrated to 60% total solid content via ultrafiltration process using membrane separation technology. Physiochemical properties of DPNR, ENR, and LATZ latex were compared. Results show that the total solid content, dry rubber content, and alkalinity level of the latexes achieved the targeted value. This study also found that nitrogen content of DPNR latex, LATZ latex, and ENR latex were at 0.11%, 0.29%, and 0.25%, respectively, indicating successful deproteinization of the DPNR latex. On the other hand, the epoxidation level of ENR latex produced in this study was at 46.3%, which is slightly lower than the targeted level of 50%. Rheological studies found that ENR latex exhibits the highest viscosity, followed by DPNR and LATZ, but all show characteristic shear-thinning behavior. This study also found that LATZ and DPNR latex are more liquid-like in nature, while ENR latex behaves more like an elastic solid. Non-ionic surfactants play a major role in influencing flow and deformation behavior of the ENR and DPNR latex.

In-Situ Epoxidation of Waste Cooking Oil and Its Methyl Esters for Lubricant Applications: Characterization and Rheology

In the present investigation, in-situ epoxidation of waste cooking oil and its methyl esters was prepared, and the rheological behavior was analyzed for biolubricant applications. Rheological properties of the prepared epoxides were measured at a temperature of 25–100 °C, at a shear rate ranging from 5 to 300 s−1. As viscosity is one of the critical parameters for potential biolubricant applications, in the present study, the power-law model was used to investigate the flow behavior of the epoxides. The viscosity of epoxidized waste cooking oil and its methyl ester epoxides showed Newtonian flow behavior in the studied temperature range. Different shear rates (5–100, 5–300, 100–300 s−1) were studied to determine the shear rate dependency of the epoxidized waste cooking oil and its methyl ester epoxides at different temperatures. From the average viscosity values, it was shown that the epoxides show identical results at all shear rates. The dynamic viscosities of the epoxidized waste cooking oil and its methyl ester epoxides were found to be dependent on fatty acid chain length, unsaturation, and temperature. Detailed physicochemical characterization for epoxide waste cooking oil (EWCO) and epoxide waste cooking oil methyl esters (EWCOME) were carried out to evaluate the properties for suitable biolubricant applications using standard American Society for Testing and Materials (ASTM) and American Oil Chemists’ Society (AOCS) methods. Based on the viscosity for EWCO (278.9 mm2/s) and EWCOME (12.15 mm2/s) and viscosity index for EWCO (164.94) and EWCOME (151.97) of the prepared epoxides, they could complement the standard ISO vegetable grade (VG) lubricants in the market.

Preparation and Properties of Poly(Lactic Acid)/Epoxidized Natural Rubber/Nano-Silica Composites

This study aimed to improve the toughness property of poly(lactic acid) (PLA) by incorporating epoxidized natural rubber (ENR), an elastomeric material and silica nanoparticle (nSiO2), a spherical inorganic nanofiller. ENR with 30mol% epoxidation (ENR 30) was first prepared via in situ epoxidation of natural rubber by performic acid generated from the reaction between formic acid and hydrogen peroxide in the latex stage. The PLA was melt blended with three weight percentages (10, 20 and 30wt%) of ENR in an internal mixer, followed by a compression molding. The effects of ENR loadings on the mechanical properties and thermal stability of the blends were first investigated. It was found that the addition of ENR 30 increased the toughness property of the blends. The blend at 20wt% ENR 30 exhibited the highest impact strength and elongation at break, and so was selected for preparing nanocomposites with three loadings (1, 2 and 3 parts per hundred of resins) of nano-silica (nSiO2). The results showed that all PLA/ENR 30/nSiO2 nanocomposites exhibited higher impact strength and thermal stability than the neat 80/20 PLA/ENR 30 blend.