Cu12 and C16 monoglyceryl ethers : preparation and characterization as water evaporation supressants

Date

5-2008

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Milagros M. Peralta

Abstract

The monoglyceryl ethers were prepared via Williamson ether Synthesis using glycerol and the coconut fatty alkyl bromides, dodecyl bromide and hexadecyl bromide, as starting materials, and tetramethylammonium iodide as phase transfer catalyst. Dodecyl and Hexadecyl bromide were prepared by reacting dodecyl alcohol and hexadecyl alcohol, respectively, with concentrated 1413r, also in the presence of a phase transfer catalyst, tetramethylammonium iodide. The reaction mixtures and products were analyzed by TLC and GC to determine the extent of conversion as well as purity. The products were further characterized using routine chemical tests, infrared spectroscopy, nuclear magnetic resonance spectroscopy and gas chromatography. The highest yield for the synthesis of dodecyl bromide was 75.4 %; while that of hexadecyl bromide was 80.81 %. Synthesis of the products 1-0-dodecylglyeeryl ether and 1-0-hexadecylglyceryl ether from these bromides gave average yields of 59.26 % and 39.30 %. respectively; while synthesis of 2-O-dodeeylglyceryl ether and 2-0- hexadecylglyceryl ether gave average yields of 46.52 % and 29.42 %, respectively. C1, and Ci6 monoglyceryl ethers were also synthesized via direct Williamson ether synthesis, eliminating the sequential protection and deprotection steps. Gas Chromatography Analysis showed that 42.13 % 1-monoglyceryl ether is present in C1, mixture while 70.62 % 1-monoglyceryl ether is present in Ci6 mixture. Cytotoxicity of the synthesized monoglyceryl ethers was evaluated through brine shrimp lethality assay. Results showed that monoglyceryl ethers have low cytotoxicity with values of LD5e lesser than 30 ag/mI. The persistence of the monoglyceryl ethers was evaluated by performing soil residue analysis. For one week, a decline in the concentration of monoglyceryl ethers was observed. After seven days, only 3.00 % Cia monoglyceryl ether and 24.44% C16 monoglyceryl ether remain in the rice paddy.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2008 C4 O78

Document Type

Thesis

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