title: Permeability of dye through poly(urea-urethane) microcapsule membrane prepared from mixtures of di- and tri-isocyanate.
abstract: Poly(urea-urethane) microcapsules were prepared by the interfacial polymerization with using mixtures of tri- and di-isocyanate monomers as wall forming materials, and dioctyl phthalate containing an oil-soluble dye as a core material. The time course of the dye release in dispersing tetrahydrofuran was measured as a function of the weight fraction of tri-isocyanate monomer in the total monomer w and the core/wall material-weight ratio g. The dye release curves were well represented by an exponential function C=Ceq(1-e-t/tau), where C is the concentration of the dye in the dispersing medium, Ceq that at equilibrium state, t the elution time and tau is a time constant. tau increased linearly against w at high g, suggesting controllability of the release rate of microcapsules by varying tri-isocyanate/di-isocyanate ratio.
authors.affiliation: Department of Textile Engineering, Faculty of Engineering, Chinese Culture University, Taipei, Taiwan 11192, ROC. cpchang@staff.pccu.edu.tw
authors.forename: Chih Pong
authors.initials: CP
authors.lastname: Chang
authors.forename: Jer Chen
authors.initials: JC
authors.lastname: Chang
authors.forename: Kimio
authors.initials: K
authors.lastname: Ichikawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Dobashi
mesh_terms: D002152:Calorimetry, Differential Scanning; D002214:Capsules; D004396:Coloring Agents / Q000493:pharmacokinetics*; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods*; D005663:Furans / Q000737:chemistry; D017953:Isocyanates / Q000737:chemistry*; D008567:Membranes, Artificial; D010539:Permeability; D010795:Phthalic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000493:pharmacokinetics*; D012997:Solvents
chemical_list: D002214:Capsules; D004396:Coloring Agents; D003692:Delayed-Action Preparations; D005663:Furans; D017953:Isocyanates; D008567:Membranes, Artificial; D010795:Phthalic Acids; D011140:Polyurethanes; D012997:Solvents; C018674:tetrahydrofuran