This study was conducted to test the effectiveness of citrus oil, d-limonene, extracted from calamansi (Citrus microcarpa) rind in dissolving expanded polystyrene foam.
Using water by distillation method at constant temperature, citrus oil was extraced from calamansi (Citrus microcarpa) rind. Analytical test on the presence of d-linolene through Spectral Elucidation confirmed that the main component of the extract is d-limonene, an aromatic and a non-polar solvent.
Different sizes of expanded polystyrene foam were treated using varying volumes of d-limonene. Six trials for each size of EPS were treated with a given volume of d-limonene. The dissolution time of each sample was measured. Variations among the sizes of the EPS and the volume of d-limonene were determined using two-way ANOVA. When the size of EPS is held constant and the volume of d-limonene is changed in increasing amounts, the dissolution time decreases. Conversely, when the volume of d-limonene is held constant and the volume of EPS is changed in increasing sizes, the dissolution time increases. Therefore, varying the volumes of the d-limonene has no significance, at 5% and 1% levels of significance, on the dissolution time if the size of EPS is changed. Furthermore, a liquid solution resulted when the volume of the EPS is less than the volume of d-limonene while a paste-like mixture was forced when the volume of EPS is greater than the volume of d-limonene.
Suffice to say that this naturally occuring solvent d-limonene is effective as a dissolution agent of EPS foam thus, promising to be a safe replacement of synthetic and toxic non-polar compounds used as solvents in disposing and recycling these non-biodegradable solid wastes.