MODIFICATION OF THE PROPERTIES OF NATURAL RUBBER BY COPOLYMERIZATION WITH A BIOPOLYMER FOR A CONTROLLED RELEASE OF UREA FERTILIZER - Fertilizers: Components, Uses in Agriculture and Environmental Impacts - page 243

Figure 21. Swelling ratio (%) of the 8:2:3 PVA/St/ENR blend in water.
Figure 21 shows the effect of the cellulose fiber on the swelling ratio of the PVA/St/ENR
blend. Before adding the cellulose fiber, the swelling ratio of the 8/2/3 PVA/St/ENR blend
was 360%. It was clear that the swelling ratio of the polymer blend decreased as a function of
the cellulose fiber content. This was due to the interaction between the hydroxyl groups from
St, PVA and ENR and the cellulose fiber.
3. E NCAPSULATION
Encapsulation is a technique in which the reactive agents, such as a herb, and fertilizer
were enclosed within some other materials such as a natural or synthetic material (Riyajan,
2011). Here, we used a modified NR for use as the polymer membrane (namely,
encapsulation model and matrix model) for an encapsulated fertilizer (Figure 22). The
product from this technique is a capsule consisting of two phases the active reagent and the
polymer matrix. The active agents were the fertilizer and herb while the polymer matrix was
the modified NR, as mentioned above.
Figure 22. Model of a fertiliserfertilizer capsules product using natural rubber latex measured by a
digital camera.