Browsing by Author "DIAZ, FR"
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- ItemA CHELATING POLYAMIDE - SYNTHESIS, CHARACTERIZATION AND REACTION WITH CU(II) ION(1983) DIAZ, FR; TAGLE, LH; OLIVARES, JP
- ItemPOLY(TETRAHALO-P-PHENYLENESELENIDE)S - NEW SEMICONDUCTING POLYMERS(1989) DIAZ, FR; TAGLE, LH; GARGALLO, L; RADIC, D; GODOY, A
- ItemPOLYAMIDE-IMIDES FROM 3',4'-DICARBOXY-4''-CHLOROFORMYL TEREPHTHALOYLPHENONE ANHYDRIDE(1975) TAGLE, LH; NEIRA, JF; DIAZ, FR; RAMIREZ, RS
- ItemPOLYAMIDES FROM PERCHLORO-4,4'-DICHLOROFORMYLBIPHENYL(1976) ESCOBAR, H; DIAZ, FR; RAMIREZ, RS
- ItemPOLYCHLORINATED POLYAMIDES .2. SYNTHESIS AND CHARACTERIZATION OF POLYAMIDES DERIVED FROM 2,5-DICHLOROTEREPHTHALOYL DICHLORIDE AND PERCHLOROTEREPHTHALOYL DICHLORIDE(1979) DIAZ, FR; GARGALLO, L; LIZANA, C; GILBERT, S
- ItemPOLYMERIZATION BY PHASE-TRANSFER CATALYSIS .1. POLYETHERS SYNTHESIS(1984) TAGLE, LH; DIAZ, FR; MUNOZ, AM
- ItemPOLYMERIZATIONS BY PHASE-TRANSFER CATALYSTS .19. SYNTHESIS AND CHARACTERIZATION OF POLY(ESTERTHIOCARBONATE)S AND POLY(ESTERTHIOCARBONATE)S(SOCIEDAD CHILENA DE QUIMICA, 1994) TAGLE, LH; DIAZ, FR; CISTERNAS, HIn this work we describe the synthesis of poly(estercarbonates) and poly(esterthiocarbonates) derived from the monomers 4-hydroxyphenyl-3-hydroxybenzoate (I) and 3-hydroxyphenyl-3-hydroxybenzoate (II) and phosgene and thiophosgene respectively. Polymers were synthesized under phase transfer catalysis conditions and using several ammonium salts as catalysts and dichloromethane as solvent. For polymers derived from 4-hydroxyphenyl-3-hydroxybenzoate (I) the more effective catalyst was TEBAC due to the hydrophilic character, being the other catalysts ineffective. For polymers derived from 3-hydroxyphenyl-3-hydroxybenzoate (II) catalysts showed no influence, and the phase transfer process is only due to an increase of the yields. All polymers were insoluble in the reaction media, which limited their growth.
- ItemQUANTITATIVE-EVALUATION OF SOLUBLE POLYMERIC PHOTOSENSITIZERS WITH 4-NITRO-1-NAPHTHYLCARBAMOYL PENDANT GROUPS(PERGAMON-ELSEVIER SCIENCE LTD, 1993) SASTRE, R; MATEO, JL; BOSCH, P; CATALINA, F; AMATGUERRI, F; DIAZ, FRSoluble polymeric photosensitizers, with various contents of the 4-nitro-1-naphthylcarbamoyl chromophore, and the corresponding low molecular weight model compound have been tested as triplet energy donors against trans-stilbene in dioxane solution. Stern-Volmer constants show that the higher the chromophore content in the polymer the lower is its sensitizing efficiency. This effect can be explained by efficient intramolecular self-quenching processes which take place in the functionalized polymers because of the large local concentrations of chromophore.
- ItemSOLUTION PROPERTIES OF POLY(2-SELENOLYMETHYL METHACRYLATE)(1988) GARGALLO, L; MUNOZ, MI; DIAZ, FR; RADIC, D
- ItemSYNTHESES, CHARACTERIZATION AND ELECTRICAL-PROPERTIES OF SEVERAL POLY(SELENO-P-ARYLENEDIAMINES)(1995) DIAZ, FR; TAGLE, LH; GODOY, A; CONTRERAS, SPolymers derived from aromatic diamines and containing selenium between the two nitrogen atoms were synthesized and characterized. The electrical conductivities were measured before and after doping with I-2, SbF5, AlCl3 and FeCl3, showing semiconducting properties when doped with I-2 and SbF5.
- ItemSYNTHESIS AND CHARACTERIZATION OF POLY(AMIDE-IMIDES) FROM 3,4-DICARBOXY-4'-CHLOROFORMYLBIPHENYL ANHYDRIDE WITH ALIPHATIC DIAMINES(1984) TAGLE, LH; DIAZ, FR; VEGA, RJ
- ItemSYNTHESIS AND CHARACTERIZATION OF POLYESTERS DERIVED FROM POLYCHLORINATED AROMATIC DIACIDS(1981) DIAZ, FR; LARRAIN, RR; FRESNO, A; RAMIREZ, RS
- ItemTHERMOGRAVIMETRIC ANALYSIS OF BISPHENOL A COPOLY(CARBONATE THIOCARBONATE)S(1989) TAGLE, LH; DIAZ, FR
- ItemTHERMOGRAVIMETRIC ANALYSIS OF COPOLY(CARBONATE THIOCARBONATE)S(ELSEVIER SCIENCE BV, 1991) TAGLE, LH; DIAZ, FRThe thermal stability and the kinetics parameters of copoly(carbonate-thiocarbonate)s from two diphenols and for three different compositions were studied. No clear relation between the thermal decomposition temperature and the carbonate content was found for the two series of copolymers. The kinetics parameters of the thermal decomposition were determined using the Arrhenius relationship and indicated a two-step degradation process, the first step being of zero kinetic order and the second of first order. The steps were associated with two different decomposition mechanisms.
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLY(ETHER-ESTER)S DERIVED FROM BISACID A-2 AND RELATED DIACIDS AND DIPHENOLS(ELSEVIER SCIENCE BV, 1991) TAGLE, LH; DIAZ, FR; VARGAS, MAThe thermogravimetric behaviour of nine poly(ether-ester)s derived from three acid dichlorides and three diphenols was studied by dynamic thermogravimetry. The thermal decomposition temperatures (TDT), the temperature at which the poly(ether-ester)s lost 10% of their weight, were also determined; they are within 30-degrees-C of each other. The kinetics parameters of the thermal decomposition were also determined. The poly(ether-ester)s in which the structures of the acid dichloride and the diphenol were the same, showed a 0 kinetic order, but when those structures were different the kinetic order was 0.5, which means that the degradation is a complex process.
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLYCARBONATES AND POLYTHIOCARBONATES FROM DIPHENOLS WITH METHYL-GROUPS(ELSEVIER SCIENCE BV, 1990) TAGLE, LH; DIAZ, FR
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLYCARBONATES AND POLYTHIOCARBONATES WITH CHLORINE ATOMS(GORDON BREACH SCI PUBL LTD, 1994) TAGLE, LH; DIAZ, FRThe thermal stability and kinetics parameters of polycarbonates and polythiocarbonates derived from diphenols with chlorine atoms in the aromatic rings were studied, showing that polycarbonates have a higher thermal stability than the polythiocarbonates. All polymers degraded in a single stage in the considered temperature range, and the kinetics parameters were determined by using the Arrhenius relationship and a computer program. Polycarbonates degraded by a zero order kinetics, while polythiocarbonates by a first order kinetic.
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLYCARBONATES WITH AROMATIC SIDE GROUPS(1989) TAGLE, LH; DIAZ, FR
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLYESTERS DERIVED FROM 2,2-BIS(4-CHLOROFORMYL-PHENYL)-PROPANE AND 4,4'-BIPHENYL-DICARBOXYL CHLORIDE(1993) TAGLE, LH; DIAZ, FRThe thermal stability and the kinetic parameters of a series of polyesters were studied by non-isothermal thermogravimetry. The thermal decomposition temperatures (TDT) depend principally on the nature of the diphenols, in the sense that when the bulk of the diphenol is increased, the TDT values decrease. The kinetic parameters, determined using the Arrhenius relationship, show that these polyesters degrade by a complex mechanism or possibly two or more superimposed processes, probably due to the complex structure of both diacids and diphenols.
- ItemTHERMOGRAVIMETRIC ANALYSIS OF POLYESTERS DERIVED FROM TEREPHTHALIC, TETRACHLOROTEREPHTHALIC AND RELATED DIACIDS WITH BISPHENOL-A(ELSEVIER SCIENCE BV, 1992) TAGLE, LH; DIAZ, FRThe thermogravimetric behaviour of polyesters derived from terephthalic, tetrachloroterephthalic and related diacids, with -CH2- and -OCH2- as spacer groups with bisphenol A as diphenol, was studied by dynamic thermogravimetry. Polyesters derived from a diacid with an entirely aromatic structure degrade at higher temperatures than those derived from aliphatic diacids owing to the flexibility of the polymeric chain. Polyesters derived from tetrachloroterephthalic acid showed a higher thermal stability than that derived from terephthalic acid, but for the aliphatic polyesters, the chlorinated form showed a lower stability than those without chlorine atoms, probably because the influence of the aliphatic character is greater. The kinetics parameters of the thermal decomposition were determined by the Arrhenius relationship; in the range considered, all thc studied polyesters degrade in a single stage, but probably via complex reactions.