02001nas a2200253   4500008004100000022001400041245008300055210006900138260006800207300001200275490000700287520113000294653002201424653001601446653002201462653002101484653001501505100002501520700002001545700002201565700001801587700002501605856011701630       2005                        eng d  a0021-899500aThermal degradation kinetics of polyesters containing mesogenic aromatic diols0 aThermal degradation kinetics of polyesters containing mesogenic   a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcAUG  a784-7920 v973 a<p>A series of polyesters were synthesized by reacting structurally differing aromatic diols with either saturated (flexible) or unsaturated (rigid) dicarboxylic acid halide by a stirred interfacial polycondensation technique. Thermal degradation kinetics of these polyesters were investigated by applying Coats-Redfern and Horowitz-Metzger nonisothermal procedures. The dynamic thermogravimetry experiments were conducted in nitrogen to obtain differential thermogravimetric plots. Thermal stability of these polyesters was discussed on the basis of semiquantitative methods such as differential procedural decomposition temperature, integral procedural decomposition temperature, and fraction decomposition temperature (e.g., 10 % DT). Degradation proceeded in multiple stages. The thermal degradation patterns and activation energies in these stages were discussed in relation to central bridging moieties of aromatic diol. The activation energies of these polyesters were found to be in the range of 100 to 200 kJ/mol. The effect of spacer type on activation energy was also reported. (c) 2005 Wiley Periodicals, Inc.</p>10aActivation energy10aDegradation10akinetics (polym.)10aPolycondensation10apolyesters1 aMule, Smita, Atmaram1 aGhadage, R., S.1 aJacob, Nalini, E.1 aRajan, C., R.1 aPonrathnam, Surendra  uhttps://library.ncl.res.in/content/thermal-degradation-kinetics-polyesters-containing-mesogenic-aromatic-diols-002127nas a2200229   4500008004100000022001400041245016000055210006900215260006800284300001400352490000700366520120600373653002201579653001901601653002901620653001301649653002201662653002701684100002901711700002501740856013201765       2007                        eng d  a0887-624X00aKinetics of hexene-1 polymerization using [(N,N `-diisopropylbenzene)-2,3-(1,8-napthyl)-1,4-diazabutadiene] dibromonickel/methylaluminoxane catalyst system0 aKinetics of hexene1 polymerization using NN diisopropylbenzene23  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAR  a1093-11000 v453 a<p>{Kinetics of hexene-1 polymerization was investigated using [(N,N'-diiso-propylbenzene)2,3-(1,8-napthly)-1,4-diazabutadiene]/dibro monickel/methylaluminoxane catalyst. Experiments were performed at varying catalyst and monomer concentrations in the temperature range of -10 to 35 degrees C. First order time-conversion plot shows a downward curvature at temperatures of 20 degrees C and 35 degrees C indicating the presence of finite termination reactions. A nonlinear plot of degree of polymerization (P-n) with respect to conversion indicates occurrence of transfer reactions and slow initiation. The experimental molar masses are higher than predicted, which implies that a fraction of catalyst species could not be activated or is deactivated at the early stages of the reactions. The efficiency of the catalyst (Cat(eff)) varies from 0.77 to 0.89. The observed polydispersity of the poly(hexene-1) s is in the range of 1.18-1.48. The reaction order was found to be 1.11 with respect to catalyst. The Arrhenius plot obtained using the overall propagation rate constant, k(p), at five different temperatures (-10, 0, 10, 20, and 35 degrees C) was found to be linear with an activation energy</p>10aActivation energy10achain transfer10adegree of polymerization10ahexene-110akinetics (polym.)10anickel (alpha-diimine)1 aSubramanyam, Ummadisetty1 aSivaram, Swaminathan  uhttps://library.ncl.res.in/content/kinetics-hexene-1-polymerization-using-nn-diisopropylbenzene-23-18-napthyl-14-diazabutadiene