Controlled release from PVC matrices: Effect of four phthalate plasticizers on diffusion of THF

✍ Scribed by D. Shailaja; M. Yaseen

• Book ID: 103073781
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 285 KB
• Volume: 28
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(92)90270-c

✦ Synopsis

Polymer matrices are used as dispensers for the controlled release of bioactive materials at rates effective either to kill or to attract pests in the fields. The release characteristics of the bioactive materials are directly related to the diffusion property of the matrix; these properties could be modified by incorporation of plasticizers. In order to develop a versatile monolithic controlled release device, a large number of PVC matrices have been prepared containing a di-n-alkyl phthalate (methyl, ethyl, butyl or octyl) at concentrations ranging from 10 to 30%. To assess the plasticizer efficiency, the diffusion coefficient of the tetrahydrofuran molecule in PVC matrices was studied by gravimetric desorption measurements. Fickian diffusion kinetics were observed in all cases. It was found that diffusion coefficient increases with increase in the plasticizer content but decreases with increase in the alkyl chain length.