THE SYNTHESIS OF MAGNETIC MOLECULARLY IMPRINTED POLYMER FOR THE SEPARATION OF DI-(2-ETHYLHEXYL)PHTHALATE

• Main Author: Rizqi Utami, Asyifa
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/52162
• Institution: Institut Teknologi Bandung

Di-(2-ethylhexyl) phthalate (DEHP) is a phthalate derivative that widely used as plasticizer mostly for polyvinyl chloride (PVC). DEHP can be easily leached out from various plastic material into environments. This compound is classified as endocrin disrupting compound and revealed reproductive toxicity towards human. The purpose of this study is to synthesize the Magnetic Molecularly Imprinted Polymer (MMIP) for a selective separation of DEHP from plastic sample. The study was initiated by synthesizing magnetite coated oleic acid. Magnetite was synthesized using Fe (II) and Fe (III) in base condition by coprecipitation method. Polymerization was carried out on the surface of the magnetite using DEHP as template, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as the crosslinker, and benzoyl peroxide as the initiator. The mol comparison between template, functional monomer and cross linkers was 1:4:20. As a comparison, MNIP (Magnetic Nonimprinted Polymer) was synthesized. MMIP and MNIP were characterized using FTIR (fourrier transform infrared) and SEM (Scanning Electron Microscope). The FTIR spectrum showed that MMIP was successfully synthesized, shown by the presence of an Fe-O peak at 586 cm-1, a carbonyl peak of methacrylic acid at 1728 cm-1 and a C-H peak of oleic acid at 2954 cm-1. SEM measurement showed that MMIP was porous and has smaller particle size than MNIP. TEM measurement showed that MMIP had Fe3O4 core with polymer covering it. MMIP had spherical shape and 48% of MMIP had size particle about 50-79 nm. About 19% of MMIP had size particle above 100 nm. VSM measurement showed that the remanence magnetism and coercivity of MMIP was 0, thus MMIP was superparamagnetic with saturation magnetism value of 39.92 emu/g. Saturation magnetism value of MMIP was lower than magnetite because of polymer layer on magnetite could decrease the magnet characteristic. MMIP also had a better adsorption capacity than MNIP with an IF (imprinting factor) value of 3.37and maximum adsorption capacity value of 17.21 mg/g. Adsorption process follow Langmuir isoterm model, showed that the adsorption process occur on monolayer of MMIP and every affinity site was homogen. Kinetics study showed studies showed that the adsorption process followed the pseudo second order reaction. Thermodynamic study showed that the reaction was spontaneus and exothermic with the change in standard entalphy value was -82.17 kJ mol-1. MMIP is selective against DEHP compared to DBP (dibutyl phthalate) as its analogue compound with a selectivity coefficient value of 4.57. Desorption study using methanol and methanol : acetic acid (9:1, v/v) showed that methanol : acetic acid (9:1, v/v) had better desoption capacity with desorption percentage was 98.42 %. The regeneration study using methanol: acetic acid (9:1, v / v) as the desorption solvent showed that MMIP had good regeneration with a decrease in adsorption capacity of 11.2% after three times regenerations. After optimization, MMIP was used for analysis of DEHP in PVC sample. Analysis was performed using HPLC-UV with wavelength at 202 nm, using C-18 as stationary phase and methanol : water (95:5 , v/v) as mobile phase. Separation of DEHP from PVC sample using MMIP showed that polymer could decrease the matrixes effect with recovery percentage about 91.03-99.68%. Concentration of DEHP in plastic sample was 0.6484 mg/g.