Biodiesel permeability in polyethylene

This paper reports solubility and diffusivity data for soy and rapeseed methyl esters in polyethylene together with comparisons with methyl oleate and linoleate. These data showed that there is no significant difference in diffusivity and solubility between all these penetrants. Data were used to discuss the reliability of predictive models for diffusion and solubility of additive type molecules into semi-crystalline thermoplastic polymers. Permeability data were monitored by a new device, the results from which are in reasonable agreement with theoretical considerations on solubility and diffusivity. They also showed that biodiesels are less aggressive towards polyethylene than diesel from a petrochemical source.