A way to enhance the mechanical performance and UV visible-light barrier of polyethylene terephthalate packaging material: Synthesis and application of takedaite (Ca3B2O6)

Abstract

The current study aimed to produce polyethylene terephthalate (PET)/takedaite (Ca3B2O6) composite bottles, an innovative packaging material with better performance. For this, Ca3B2O6 was firstly synthesized by sol-gel route and then it was incorporated to PET at five rates by extrusion. Finally, preform and PET bottles were produced by injection and stretch-blow-molding processes, respectively. The results showed that the use of Ca3B2O6 significantly improved the mechanical performance and UV transmittance of PET. Compared to pure PET, the load-carrying capacity and burst strength enhanced by 133.66% and 54.16%, respectively. Environmental stress cracking (ESC) time increased from 0.3 to 18 min at 0.8% Ca3B2O6 concentration. Moreover, UV transmittance (similar to 85%) of PET decreased to approximately similar to 18% in the visible region with the incorporation of 0.8 wt% Ca3B2O6. In terms of chemical degradation, Ca3B2O6 incorporation did not change the diethylene glycol (DEG) and isophthalic acid (IPA) rates, however it played an enhancing and reductive role in acetaldehyde (AA) and carboxylic acid (COOH) degradations, respectively. Accordingly, this novel product offers the opportunity to minimize the problems that may occur due to transportation/storage and photocatalytic degradation of food and beverages in PET packaging.