Bisphenol A (BPA)-imprinted polymer for the binding and molecular recognition of bisphenol compounds

Date of Publication

2012

Document Type

Master's Thesis

Degree Name

Master of Science in Chemistry

College

College of Science

Department/Unit

Chemistry

Abstract/Summary

Bisphenol compounds such as BPA, BADGE and BFDGE are known carcinogenic and mutagenic contaminants that can leach to food from the can packaging. Tolerable limits set by regulatory institutions suggest a stringent analytical technique to analyze and remove these toxic substances. Molecular imprinting is a technique of introducing active recognition sites in the polymer matrix, hence the prepared polymeric materials could selectively bind target compound. This study aims to synthesize and characterize BPA-imprinted polymer (MIP) as potential sorbent for bisphenol compounds. In the rational design of MIP, MMFF94 theoretical technique was used to assess the favorable binding energies of interacting template-monomer systems, template-monomer ratios and rebinding solvents that could possibly impart good imprinting characteristics. The ideal MAA-BPA (4:1) molar ratio of the synthesized polymers and the rebinding solvent (50% ACN/50% toluene) was established via computational technique using MMFF94. The new BPA-imprinted polymer was synthesized by precipitation polymerization using mecthacrylic acid (MAA), bisphenol A (BPA), trimethylolpropane trimethacrylate (TRIM), and 2,2azobis(isobutyronitrile) (AIBN) as functional monomer, template, cross-linker, and initiator, respectively. Results of infrared spectroscopy, fluorescence microscopy and elemental analysis revealed that molecularly imprinted polymer (MIP) was successfully synthesized. Scanning electron micrograph showed that the MIP’s are relatively uniform microparticles with high degree of porosity. This suggests that these imprinted polymers are suitable as sorbent for column separation. xvi Scatchard plot characterized MIP as having two binding recognition types. The stronger affinity binding type exhibits dissociation constant (Kd) 20 times smaller that that of the weaker type with binding capacity of 68.597 mg BPA/g MIP. Subsequent Freundlich isotherm further demonstrated the heterogeneity of the binding sites of the MIP with heterogeneity index, a (0.4758)<1, and average affinity, m=3.5867. Competitive selectivity study showed that BPA-imprinted polymer rebinds other related compounds but considerably higher for BPA as manifested by relatively high imprinting factor. This implies that the MIP can be considered relatively selective for binding BPA. With this, it is recommended to further strengthen the study by applying this imprinted polymer in the real food extracts.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTG005261

Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall

Physical Description

1 computer optical disc ; 4 3/4 in.

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