Browsing by Author "SALGADO, E"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    THERMAL STUDIES OF METAL POLY(BUTYL METHACRYLATES) .13.
    (GORDON BREACH SCI PUBL LTD, 1994) CARDENAS, G; SALGADO, E; TAGLE, LH
    Metal poly(butyl methacrylates) polymers were obtained by radical polymerization with benzoyl peroxide. The monomer was cocondensed with the metals: Cu, Ag, Au, Pd, Zn, Cd, Ga, In, Ge, Sn, Sb and Bi. The metals were evaporated to produce atoms and with the monomer they can generate a matrix at 77 K. After the warm up process, metal-monomer colloids can be obtained. The colloids were polymerized with benzoyl peroxide at 70 degrees C for 0.5 h at 70 degrees C. Four different initiator concentrations (0.5, 1.0, 1.25 and 5.0 mol%) were used. The yields are over 50% and the viscosimetric molecular weight range from 10(4)-10(5) g/mol. The higher My are Sb, In, Ag and Ge-poly(butyl methacrylates). The thermal stabilities of these metal polymers have been studied by thermogravimetry (TG) between 25 and 550 degrees C under nitrogen flow. The decomposition temperature was obtained from the maximum of the first derivative from TG curve. The kinetic parameters of the thermal decomposition were determined by the Arrhenius equation. All these polymers degrade in a single step around 300 degrees C. The kinetic data thus obtained show the thermostabilities decrease in the order: Pd-PBMA > Au-PBMA > In-PBMA > Sn-PBMA > Ag-PBMA > Sb-PBMA > Bi-PBMA > Ge-PBMA > Zn-PBMA > Ga-PBMA > Cu-PRMA > Cd-PBMA. The thermal stability apparently is depending upon the metal incorporated in the polymer matrix. The decomposition reaction order is -0.25 or -0.5 which means that we are in the presence of a complex single decomposition reaction, The pre-exponential factor, the activation energy, the reaction order and the decomposition temperature for all the polymers have been determined.
  • No Thumbnail Available
    Item
    THERMAL STUDIES OF METAL POLY(N-BUTYL METHACRYLATES) .10.
    (1993) CARDENAS, G; SALGADO, E; TAGLE, LH
    Metal poly(n-butylmethacrylates) polymers were obtained by radical polymerization with azodiisobutyronitrile (AIBN). The thermal stabilities of the metal polymers (M-PBMA) have been studied by thermogravimetry (TG) between 25 and 550-degrees-C under nitrogen flow. The decomposition temperature was obtained from the first derivative of the TG curve. The kinetic parameters of the thermal decomposition were determined by the Arrhenius equation. All these polymers degrade in a single step. The kinetic data thus obtained show that the thermostabilities decrease in the order Pd-PBMA > Ga-PBMA > Cu-PBMA > Ag-PBMA > Au-PBMA > Al-PBMA > Cd-PBMA > Ge-PBMA > Zn-PBMA > Sb-PBMA > In-PBMA > Sn-PBMA. In fact, the thermal stability is dependent upon the metal incorporated in the polymer, the highest being stable up to 389-degrees-C and the lowest up to 260-degrees-C. The order of reaction from the thermal decomposition of these metal polymers was found to be -0.25 for the homopolymers, Pd, Au, Ag, Cd, Zn, Ga, Ge and Sn but -0.5 for Bi, Sb and Al. The pre-exponential factor, the reaction order and the activation energy of the decomposition reaction for M-PBMA have been determined.