Starch ̶ Urea Inclusion Complexes as Controlled Release Fertilizers (CRF)

• Main Author: SATRIA (NIM: 10512031), MAULIADY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28802
• Institution: Institut Teknologi Bandung

<p align="justify">In agricultural country, the development of the agricultural sector plays an important role in overcoming the problems of the nation's economy. The success and effectiveness of fertilization were a key to improve the agricultural sector. Urea is a fertilizer that is commonly used in agriculture due to its relatively high nitrogen content of 46%. The usage of urea fertilizers in Indonesia reached 6.9 million tons in 2015. However, urea efficiency is still low because most of the fertilizers nutrients are loss into the environment. This loss is due to the content of nitrogen released into the air and the environment is faster compared takes up the nutrients. In this case, the accumulation of urea fertilizer caused significant environmental pollution. For solving this problem, urea fertilizers can be modified by complexation using starch as a natural polymer which is one method of the known as Controlled Release Fertilizers (CRF). The starch component on CRF which complexes the urea molecule will be degraded first, so the release of the nitrogen content in urea becomes more controlled. This method is economy-friendly as starch is easily available biodegradable material, environmentally friendly and is water based. In this study, amylose in starch as a host molecule which is complexed with two different kinds of guest molecules which are urea and N-dodesilurea. N-dodesilurea was synthesized using the alkylation reaction between urea with 1-bromododecane. The CRF complexes were prepared by mixing starch (3,5 &#822; 6,0% w/v) and guest molecules (20,0 &#822; 55,0% w/w based on the weight of starch) using water as solvent. The resulting of the inclusion complexes were 37,0 to 45,0%. The degradation test showed a weight loss for the complexes with respect to time. The FTIR results showed there were shift in peaks for absorption carbonyl functional group (C=O) from 1670 to 1620 cm-1, the functional group (C-O-C) glycosidic from 1080 to 1010 cm-1, the functional groups alkanes (-CH2-) from 2940 to 2910 cm-1, the (C-N) functional group from 1393 to 1300 cm-1, and hydroxyl group (-OH) from 3490 cm-1 to 3390 cm-1. The XRD results showed crystalline peaks at 2&#952; of 13,36o and 30,00o which correspond to the presence of V6-amylose in the complex. The SEM pictures depicted that there are some cubics crystalline with the size of 2,032 x 1,920 &#956;m and 2,017 x 1,224 &#956;m which a dimention of CRF.<p align="justify">