Structural and Mechanical Properties of Paraffin Wax Composites

Biodegradable Polymer Coated Granular Urea Slows Down N Release Kinetics and Improves Spinach Productivity

“…At 3256 cm −1 , the G-1 treatment showed an OH vibration, which implied that water was absorbed. The alkyne (C≡C) stretching vibration at 2178 and 2009 cm −1 can be ascribed to the presence of PVA and starch as coating materials [65]. The carbonyl (CO) peak was observed at 1627 cm −1 .…”

“…The carbonyl (CO) peak was observed at 1627 cm −1 . The sharp peaks appeared at 1465 cm −1 was due to presence of amide functional group in urea [65]. The additional peaks of nitrile (C≡N) at 2100 cm −1 and aldehyde (=C-H) at 2803 cm −1 were due to the presence of gelatin and gum arabic used as coating materials [55,65].…”

“…The results of this test are presented in Figure 4. The G-0 treatment (uncoated urea) was crushed at a force of 30.55 N. The highest crushing strength of G-2 treatment (Figure 4) was due to the presence of active ingredient paraffin wax [65]. The PVA and starch formed a compact film around the urea granule, whereas paraffin wax tightly sealed the whole granule surface and therefore showed the highest strength [63].…”

“…The coating layer of starch and PVA bonded with molasses gradually disintegrated and reached a point where the burst release of urea occurred, as was the case for the G-0 Treatment. The highest efficiency of G-2 was ascribed to the low dissolution of paraffin wax as a coating material in water that helped to retard the urea release rate [56,65]. In the aforementioned treatment, starch and PVA formed more reliable coating with wax as compared to molasses.…”

“…Conversely, the adhesion property of molasses might create a more compact coating layer on the granule surface as molasses bound efficiently with gelatin and gum arabic to form coating with additional levels of compactness (Figure 1e). However, due to the hydrophilic properties of gelatin and molasses, the combination failed to retard the release rate more than 4.2%, at which point the gelatin started to swell and allowed water to penetrate the film, which might dissolve the core [56,65].…”