Influence of d-limonene absorption on the physical properties of refillable PET

The absorption of d-limonene into polyethyleneterephthalate (PET) at different initial limonene concentrations and storage temperatures and the effect of this addition on the physical properties of PET were investigated. Strips of PET were immersed in model solutions (160 and 320 ppm limonene) for 45 days at 5, 22 and 37°C. The level of sorbed d-limonene and PET physical properties (tensile strength, modules of elasticity, and % elongation) were monitored as a function of time. Results indicated that the degree of absorption of d-limonene was dependent upon storage temperature and initial limonene concentration. The majority of limonene was absorbed after 30 days at 22 and 37°C, but at 5°C, less absorption was observed. It was found that impact strength and modules of elasticity properties of PET were significantly affected with the level of absorption of d-limonene (at confidence level 0.05), while the elongation was not influenced.