• Title/Summary/Keyword: viscosity increase

Search Result 31, Processing Time 0.031 seconds

Studies on the Graft Polymerization of Polyethyleneglycol Monomethacrylate onto Chitosan and Drug(Vitamin B12) Permeation Behavior (키토산과 폴리에틸렌글리콜 모노메타크릴레이트의 그라프트중합과 약물(Vitamin B12)방출에 관한 연구)

  • Chung, Joo-Eun;Chung, Byung-Ok;Chang, Byung-Kwon;Choi, Kyu-Suk
    • Applied Chemistry for Engineering
    • /
    • v.5 no.3
    • /
    • pp.524-536
    • /
    • 1994
  • Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

  • PDF