Polyethylene terephthalate bottles with excellent oxygen, water vapor barrier and mechanical performances prepared by injection and blow molding

In this work, the oxygen barrier property of polyethylene terephthalate (PET) films was enhanced by optimizing the “active” and “passive” synergistic barrier approaches, that is, integration of high barrier material polyethylene naphthalate (PEN) and oxygen scavengers along with catalyst with PET before biaxially stretching the PET blended films. When the PEN content in the PET blended films reached 50 wt%, the oxygen permeability coefficient was significantly reduced to 0.9687 cc·mil·m⁻²·day⁻¹·0.1 MPa⁻¹, showing an enhancement of 117.4 times compared to the pure PET film. Furthermore, the water vapor permeability coefficient was reduced to 8.0208 g·mil·m⁻²·day⁻¹, representing a 45.5% reduction in comparison to the pristine PET film. It also maintained a higher transverse and longitudinal tensile strength (110.5 and 127.2 MPa) than PET film only with oxygen scavengers and catalyst (53.5 and 78.0 MPa). This work presents a viable and practical approach to endow PET materials with simultaneously enhanced oxygen, water barrier performance, and mechanical property. Highlights: The OPC of PET film was as low as 0.9687 cc·mil·m⁻²·day⁻¹·0.1 MPa⁻¹. The “active” and “passive” barrier techniques together reduced the OPC of PET film.