Preparation of urea- formaldehyde resins for the development of slow-release fertilizers

Date

4-1993

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Aloysius U. Baes

Abstract

ROSARIO, REX SALVADOR LANTIN. College of Arts and Sciences, University of the Philippines Los Banos, April 1993. PREPARATION OF UREA-FORMALDEHYDE RESINS FOR THE DEVELOPMENT OF CONTROLLED-RELEASE FERTILIZERS.

Adviser : Dr. Aloysius U. Bees

Urea-formaldehyde resins were prepared under alkaline conditions using the method described by Jada (1988). These materials were studied for their potential in the development of slow-release fertilizers (as coating and/or source of nitrogen). Five molar ratios of urea to formaldehyde were used as reactants namely 1:2, 1:2.25, 1:2.5, 1:2.75, and 1:3. The highest relative yield was obtained for the 1:2 ratio (91.3%)and lowest for the 1:3 ratio (52.1%). The total nitrogen content of the products was found to be almost the same for all ratios (16.7%). Infrared spectral analysis of the products indicate the presence of secondary amide, methylene and methylol functional groups which are not detected in the spectra of urea. This suggests the formation of resin condensation products.

The relative solubilities of the resins in water were determined by monitoring the nitrogen (N) content of the dissolving solution weekly for a three-week period. The amounts of nitrogen released from 100 mg samples of the 1:2 and 1:2.25 ratios were found to be almost constant during the test period (14.96 and 5.95 mg N, respectively). The 1:2.5, 1:2.75, and 1:3 ratios were observed to release nitrogen slowly and continuously, with the 1:3 ratio Ilireleasing the slowest (5.80, 7.36 and 13.60 mg N for the first, second and third week, respectively).

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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