Columbia International Publishing American Journal of Materials Science and Technology (2014) Vol. 3 No. 1 pp. 22-32 doi:10.7726/ajmst.2014.1003 Research Article ______________________________________________________________________________________________________________________________ *Corresponding e-mail: ait_yalam@yahoo.fr 1 Universite de Sidi Bel abbes. Fac des Sciences. Algeria. 2* Dept. Genie Mecanique. Université de Bouira. Algeria. 3 Fac des Sciences. Universite de Tiaret . Algeria. 22 Enhanced Mathematical Modeling of DOP Plasticizer Migration from PVC into Liquid (Methanol) Mostefa Miloudi 1 , Abdelmadjid Ait Yala 2* , Mokhtar Mokhtari 3 Received 24 August 2014; Published online 13 September 2014 © The author(s) 2014. Published with open access at www.uscip.us Abstract Polyvinyl chloride, commonly abbreviated PVC is a rather hard and rigid material. In order to extend its use it requires additives during the manufacturing process which are referred to as plasticizers, among them the Dioctyl Phthalate (DOP). This latter has a tendency to escape from the PVC matrix specially when in contact with liquids. In order to analyse this phenomenon we use the classical equations of mass diffusion (Fick’s second law). However this method leads to results which are not always in good agreement with experimental ones, especially when the concentration of plasticisers is high. This situation requires the elaboration of an enhanced mathematical model that can deal with this particular type of forced diffusion characterized by the contact with a liquid and particular boundary conditions. The validation of the proposed model was obtained by comparing the theoretical results obtained with the model and those obtained by experiments. Key words: DOP; Forced diffusion; Mathematical model 1. Introduction Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer with a linear structure. It is a rather hard and rigid material and this limits its applications. In order to extend its use it requires additives during the manufacturing process which are referred to as plasticizers. We then refer to it as plasticized PVC or flexible PVC. Hence plasticizers make plastics flexible and durable which broadens their use. Because of its properties and low cost, Dioctyl Phthalate (DOP), is by far the most commonly used plasticizer in flexible PVC applications(Papakonstantinou and Papaspyrides,1994; Persico et al ,2009; Lorz et al,2002 and Wilson ,1995). Depending on the final use of the polymer, the plasticiser content in PVC varies from 15 % to 60 %. Since they are not chemically bonded with the polymer matrix